Idea Transcript
PERTftniKfl December 1984
Vol. 7 No. 3
Page Added Soy Proteins in Processed Meats in Malaysia. Aminah, A.
A.S.
Babji, Adrian, A. and 1
Status Fosfat Organik dalam Tanah Siri Bungor dengan Sistein Tanaman Tunggal dan Giliran. H. Aminuddin, S. Abdul Kadir, Rt Anuar dan Y. Khanif Peniprosesan Kimia ke atas Buangan Pertanian Padi.
5
Md. Xordin Hj. I.ajis. Atari Mohd.
Sharif and Mohd. Aspollah Hj. SukarL
13
Provisional Climatic Regions of Peninsular Malaysia.
I. D. Bishop.
19
The Reproductive Characters of Tour Varieties of Groundnuts (Arachis hypogaea L.J. t'.S. Urn and Othman Hamdan Growth, Mortality and Recruitment Patterns of Amblyrhynichthvs truncatus (Bleekcr) in Pay a Bungor, Pa hang. Mohd. A: mi Ambak
25 33
Biochemical Changes, Use of Polyethylene Bags, and Chilling Injury of Carambola '•rhoa carambola L.) Stored at Various Temperatures. - C.K. Wan and P.F. Lam
39
i'erineal Urethrostomy in a Dog with a Severed Penis. - W.T. Wong
47
Factors Affecting Ovi positional Behaviour of Scutellista cyanea, an Egg-par asi to id of Hemispherical Scale. A. Ghani Ibrahim. Assessment of Damage by the Rice Moth, Corcyra cephalonica (St.) on Different Grains at Four Levels of Moisture Content. - Noorma Osman.
49 53
Conductance Measurement of Water-sorbed Activated Carbon . - M. Badri, Karen A. Crouse and Harun Awang.
59
A Simplified Method of Calculating Propeller Parameters for Small Trawlers. Husin and Zainal Ashirin Shahardin.
67
Juhari
Primary Productivity and Mineral Nutrient Status of some Estuarine and Coastal Waters along the East Coast of Peninsular Malaysia during the off Monsoon Period. Lokman Shamsudin, M. ha Mansor and Juhari Husin. The Effect of Protein (as Fish Meal) on Rumen VFA Patterns of Molasses-fed
79
Sheep
orhani Abdullah.
89
The Attitudes of Malaysians Towards Soybean Products. •
P. S. Yeo
95
Phytoplankton Composition and Productivity of a Shallow Tropical Lake. -M.Y. Fatimah; A.K. Mohammad Mohsin and A.S. Mustafa Kamal. Some Quality Parameters of Intermediate Moisture, Deep-Fried Mackerel (Scomberomorus commersoni, Lacepede). -- Y. Che Man, and M. Atan.
101 115
Communications: Isolation of Corvnebacterium^Suis from Boars in Selangor, Malaysia. - A.R. J. Y.S. Lee, H. L. Too and J.E. T. Jones.
Bahaman, 121
The Effect of Different Soil Types on Growth and Nodulation of Vigna radiata (L) Wilczek Inoculated with Vesicular-arbuscular Mycorrhiza (VAM). Azizah Out Ian (Hashim) AJ.M. Kamal and M. Omar.
123
Perubahan Kanji dan Gula dalam Proses Kematangan Buah-buahan.
1 27
H. Marziah.
The Glue Joint Strength of Laminated Timber Decking made from Three Malaysian Hardwood Species. - Mohd. llamami Sahri.
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131
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Research Management Centre Universiti Putra Malaysia Number 3 , December 19S4rdang, SeiangorDarul Ehsan Contents Page
Added Soy Proteins in Processed Meats in Malaysia. - A.S. Babji, Adrian, A. and Aminah, A. Status Fosfat Organik dalam Tanah Siri Bungor dengan Sistem Tanaman Tunggal dan Giliran. - H. Aminuddin, S. Abdul Kadir, R. Anuar dan Y. Khanif Pemprosesan Kimia ke atas Buangan Pertanian Padi. - Md. Nordin Hj. Lajis, Atan Mohd. Sharif and Mohd. Aspollah Hj. Sukari.
13
Provisional Climatic Regions of Peninsular Malaysia. - I. D. Bishop.
19
1 5
The Reproductive Characters of Four Varieties of Groundnuts (Arachis hypogaea L.). E.S. Urn and Othtnan Hamdan Growth, Mortality and Recruitment Patterns of Amblyrhynichthys truncatus (Bleeker) in Paya Bungor, Pahang. - Mohd. Azmi Ambak Biochemical Changes, Use of Polyethylene Bags, and Chilling Injury of Carambola (Averrhoa carambola L.) Stored at Various Temperatures. - C.K. Wan and P.F. Lam
33
Perineal Urethrostomy in a Dog with a Severed Penis. - W.T. Wong
47
Factors Affecting Ovipositional Behaviour of Scutellista cyanea, an Egg-parasitoid of Hemispherical Scale. - A. Ghani Ibrahim. Assessment of Damage by the Rice Moth, Corcyra cephalonica (St.) on Different Grains at Four Levels of Moisture Content. - Noorma Osman, Conductance Measurement of Water-sorbed Activated Carbon. - M. Badrit Karen A. Crouse and Harun Awang. A Simplified Method of Calculating Propeller Parameters for Small Trawlers. - Juhari Husin and Zainal Ashirin Shahardin. Primary Productivity and Mineral Nutrient Status of some Estuarine and Coastal Waters along the East Coast of Peninsular Malaysia during the off Monsoon Period. Lokman Shamsudin, M. ha Mansor and Juhari Husin. The Effect of Protein (as Fish Meal) on Rumen VFA Patterns of Molasses-fed - NorhaniAbdullah. The Attitudes of Malaysians Towards Soybean Products. - P. S. Yeo
25
39
49 53 59 67
79
Sheep
Phytoplankton Composition and Productivity of a Shallow Tropical Lake. -M.Y. Fatimah; A.K. MohammadMohsin and A.S. Mustafa Kamal Some Quality Parameters of Intermediate Moisture, Deep-Fried Mackerel (Scornberomorns commersoni, Lacepede). - Y. Che Man, and M. Atan.
89 95 101 115
Communications: Isolation of Corvnebacterium Suis from Boars in Selangor, Malaysia. - A.R. Bahaman, J.Y.S. Lee, it. L Too and J.E.T. Jones. The Effect of Different Soil Types on Growth and Nodulation of Vigna radiata (L) Wilczek Inoculated with Vesicular-arbuscular Mycorrhiza (VAM). - Azizah Chulan (Hashimj A.J.M. Kamal and M. Omar.
121
123
Perubahan Kanji dan Gula dalam Proses Kematangan Buah-buahan. -M. Marziah.
127
The Glue Joint Strength of Laminated Timber Decking made from Three Malaysian Hardwood Species. - Mohd. Hamami Sahri.
131
Members of the Editorial Board Prof. Chin Hoong Fong M. Agri. Sc, Ph.D. (Melb.) F.I. Biol. (Lond.).
Faculty of Agriculture. (Chief Editor)
Prof. Ahmad Mahdzan Ayob B. Hort Sc. '(Cant), M.S.A., Ph.D. (Florida).
Faculty of Resource Economics and Agribusiness. (Business Manager)
Prof. Abdul Latif bin Ibrahim D. V.M. (Mymensingh), M.S. (Hawaii), Ph.D. (U.C. Davis).
Faculty of Veterinary Medicine and Animal Science.
Assoc. Prof. Asian bte Mohd Zain B.S. (Iowa), M.Sc. (Reading).
Faculty of Food Science and Technology.
Assoc. Prof. Ang Kok Jee B.Sc. (Madras), M.Sc. (Malaya), Ph.D. (Waterloo).
Faculty of Fisheries and Marine Science.
Assoc. Prof. Badri bin Muhamad B.Sc. (Hons.) (St. Francis Xavier), Ph.D. (Dalhousie).
Faculty of Science and Environmental Studies.
Dr. Kamis bin Awang B.Sc. (For.) (Hons.) Ph.D. (A.N.U.).
Faculty of Forestry.
Assoc. Prof. Kwok Chee Yan B. Agr. Sc. (Malaya), M.Sc. (Reading).
Faculty of Agricultural Engineering.
Assoc. Prof. Mohd. Nawi bin Abd Rahman B. Sc. (Malaya), M.S. (U.P.L.B.) Ph.D. (N.C. State).
Faculty of Science and Environmental Studies.
Assoc. Prof. Sulaiman bin Mohd Yassin B. Agric. Sc. (Hons.) Malaya, M.P.A. (C.A.), Ph.D. (Cornell).
Centre for Extension and Continuing Education.
Azizah Abdul Rahman B.A. (Hons.) (Malaya), M.S. (Wisconsin).
Faculty of Educational Services.
Sumangala Pillai B. Soc. Sc. (Hons.)
Universiti Pertanian Malaysia Press. (Secretary)
Pertanika 7(3), 1-4 (1984)
Added Soy Proteins in Processed Meats in Malaysia A.S. BABJI, ADNAN, A. and AMINAH, A. Department of Food Science and Nutrition, Faculty of Life Sciences, Universiti Kebnngsaan Malaysia Bangi, Selangor, Malaysia. Key words: Added soy proteins; processed meats; enzymatic method. RINGKASAN Dua kaedah digunakan untuk menentukan jumlah protein soya yang terkandung dalam beberapa hasil daging proses. Penggunaan protein soya makin meningkat kerana harga daging yang mahal. Oleh sebab tidak ada kawalan yang rapi, penggunaan bahan tambah seperti protein soya digunakan dengan tidak terhad sebagai pengganti kepada daging. Hasil kajian ini menunjukkan hasil-hasil daging seperti burger dan frankfurter mengandungi di antara 5 — 25% protein soya. Apabila kedua-dua kaedah dibandingkan, didapati kaedah enzimatik adalah lebih sensitif daripada kaedah pengemparan. Bagaimanapun, didapati kaedah pengemparan adalah lebih sesuai untuk digunakan dalam kawalan mutu, ia lebih murah dan praktikal. SUMMARY Two methods were used to determine the amount of soya protein added in some local processed meat products. The use of soya protein in processed meat formulation is increasing because of the high cost of meat. At present there are no strict measures to ensure the proper use of food extenders in meat and other products. Results from this study indicate that most meat products such as burgers and frankfurters produced locally contain between 5 - 25% added soya protein. The enzymatic method of determining soya protein was found to be more sensitive than the centrifugation method. However, for routine quality control work, the AOAC (1980) centrifugation method would be more practical and economical.
INTRODUCTION
Non-meat ingredients are commonly added to meat products for many reasons, some of which include curing, seasoning, binding, preservation and bulking associated with the final properties of the meat products. In Malaysia, soya-protein is becoming important as food binders, fillers and for bulking pupposes. This is especially true for the processed meat industry where meat substitutes are added to replace meat in order to reduce the cost of production. Soya protein is one of the easily available protein sources and increasing quantities are being used as human foods (Seal, 1980). Although the use of soya protein in meat and meat products is strictly regulated overseas, in Malaysia, there is
currently no specific regulation concerning its use in local meat products. Secondly, preparation of samples for analysis is cumbersome and tedious because other nonmeat materials are added besides soya protein. A method using enzyme galactose dehydrogenase was used by Morrissey et aL (1982). This procedure involves acid hydrolysis of soya meat blends and determining the free galactose plus arabinose values, which are found to be linearly dependent on the amount of soya added. The AOAC (1978) developed a rather quick centrifugation method for the determination of soya protein in meat products. This method utilises the fact that dilute acid will dissolve the hemicelluloses of soya protein, but not the cereal flour starch. The hemicelluloses are then precipitated with 95% ethanol which is then quantitated following a carefully controlled contrifugation.
A.S. BAB.M, ADNAN, A. AND AMINAH, A. This study is aimed at investigating the use of soya protein in local processing of meats and also at comparing the two methods recently used in countries overseas for monitoring the use of soya protein in meat product^ It is hoped that with the preliminary pegs'* were formed. The peg is a stalk-like structure (the gynophore) that develops from the base of the ovary and carries at its tip the fertilized ovules that eventually develop into kernels as the pod matures.
THE REPRODUCTIVE CHARACTERS OF FOUR VARIETIES OF GROUNDNUTS TABLE i Mean flower production per groundnut plant Variety Flowers Early
Nudong
V-13
Matjam
Alabama
26.5 )
37.8 )
40.7 )
26.9 )
) * 21.2 )
21.8 )
) ns
) ns
) ns
Late
29.2 )
23.8 )
Total
55.7
61.6
61.9
48.7
Range
22 104
29-142
27-133
18 118
2.14
2.28
1.92
2.19
S.E.
* = P < 0.05
ns - P > Q.05
TABLE 2 The distribution of groundnut flowers for the length of hypanthium Frequency (% flowers studied) Ilypanthium length (cm)
Xudong
V-13
Matjam
Alabama
2.4
3
3
4
4
2.5 - 2.9
6
8
8
9
3.4
20
16
22
12
3.5 - 3.9
24
18
22
25
4.0
4.4
34
31
23
32
4.5 - 4.9
11
15
12
16
5.0 - 5.4
1
5
7
1
5.5 - 5.9
1
2
2
0
6.0 and above
0
2
0
0
Mean hypanthium 3.8 length (cm)
3.9
3.9
3.8
2.0
3.0
available, only 15 percent of the yield potential was realised.
The number of pegs and pods produced were not significantly different among the varieties studied. An average of 50 percent of the flowers developed into pegs and out of these only 30 percent continued development into mature pods (Table 5). Based upon the number of flowers
Further loss of yield potential was evident from the limited development of the fertilized ovules (developing kernels) to maturity. The 27
E.S. LIM AND OTHMAN HAMDAN TABLK 3 Pollen viability of groundnut flowers Pollen Produc tion
Pollen Viability
No. Per Flower
S.E.
% Germination
S.E.
Nudong
7750
125
88.7
2.09
V~13
8250
205
90.6
2.12
Matjam
8700
215
90.5
2.17
Alabama
8125
250
89.3
2.48
Variety
TABLE 4 Percentage of ovaries with 1, 2, 3 and 4 ovules Mean no. of ovules per ovary
Percentage of ovaries Variety 1 ovules
2 ovule
3 ovule
4 ovule
Nudong'
0
8
48
44
3.24
V 13
0
95
5
0
2.08
Matjam
0
97
3
0
2.01
Alabama
0
97
3
0
2.13
TABLE 5 Peg and pod production of groundnuts Pegs
Mature Pods
Variety Mean No./plant
Percent of flowfers
Nudong
27.4
49.2
V 13
31.4
Matjam
Mean No./plant
Percent of Pegs
Percent of Flowers
6.0
22.2
11.0
51.8
10.0
32.8
17.2
29.2
47.2
10.3
35.0
16.9
Alabama
25.3
52.0
7.8
31.2
16.2
Mean
28.3
50.0
8.5
30.3
15.3
Differences between the varieties not significant at P * 0.05 28
THE REPRODUCTIVE CHARACTERS OF FOUR VARIETIES OF GROUNDNUTS number of developing kernels within the pegs varied. With the exception of the variety Nudong, the other varieties generally contained 2 developing kernels in the peg. The Nudong variety had many pegs with 3 and 4 developing kernels (Table 6).
were obtained when the distribution of pegs was compared with that of pods for kernel numbers (Table 8). All varieties exhibited a similar pattern of an increase in the number of pods with 1 and 2 kernels. Thus, in addition to the low pod set, the low number of fertilized ovules that developed into mature kernels further reduced the yield.
During the development of the pegs into pods many of the developing kernels aborted. In all the varieties studied, most of the pods contained 2 kernels. The Nudong variety had, in addition, many 3-kerneled pods. Single-kerneled pods were also found (Table 7).
DISCUSSION In all seed crops, yield is dependent to a large extent upon the basic reproductive units available. In groundnuts the basic reproductive units constitute the flowers. The production pattern of the groundnut flowers favour pod setting. The extended period of flowering is an advantage when conditions are less than favourable
The distribution of pegs for the number of developing kernels was not significantly different from the distribution of ovaries for the number of ovules present. However, significant differences
TABLE 6 Percentage of pegs with 1, 2, 3 and 4 developing kernels (DK) Percentage of pegs Mean Number DK/peg
Variety 1 DK
2 DK
3 DK
4 DK
Nudong
0
7
62
31
3.24
V-13
0
92
8
0
2.08
Matjam
0
91
9
0
2.09
Alabama
0
87
13
0
2.13
TABLE 7 Percentage of pods with 1, 2, 3 and 4 kernels Percentage of pods Mean Number kernels/pod
Variety 4 kernels
1 kernel
2 kernels
3 kernels
Nudong
11.2
50.6
35.8
2.4
2.29
V-13
12.2
86.8
1.0
0
1.89
Matjam
13.1
85.7
1.2
0
1.91
Alabama
11.5
86.4
2.1
0
1.91
29
E.S. LIM AND OTHMAN HAMDAN TABLE 8 Summary of Chi-square values for comparisons between distributions for the number of ovaries, pegs and pods according to the number of ovules, developing kerbels or seeds present Distributions compared
Variety Nudong
V-13
Matjam
Alabama
Ovaries vs. Pegs
4.10 ns
0.74 ns
3.19 ns
6.79 ns
Ovaries vs. Pods
81.24 **
15,24 **
16.32 **
12.27 **
Pegs vs. Pods
75.71 **
17.80
21.70 **
19.37 **
• *
ns = P > 0.05
to pollination and fertilization. The flowering peaks observed in all varieties to follow rainfall are also plant responses to match favourable weather conditions with flower production. However, very late flowers would not have adequate time for pod development before the harvest. Pods take about 8 weeks to mature from the time of flowering and therefore, only the first 3 weeks of flowering may be considered to be useful. The number of flowers produced during the first 3 weeks varied among the varieties but were more than 3 times the number of pods produced.
stress have been cited (Ono and Ozaki, 1974). The length of the style as indicated by the hypanthium length can also influence the success of fertilization. The hypanthium length was found to range, from 2 to 6 cm. The rate of pollen tube growth has been estimated at 1 cm per hour after an initial lag period of 2 hours for pollen germination (Lim and Siegfred, 1984). Thus, the flowers would require from 4 to 8 hours for fertilization to be affected. Although no study was made to relate the length of the hypanthium to peg formation, it is possible that fertilization of the ovules would be more likely to be achieved for flowers with short styles.
Pollination and fertilization are necessary before further development can take place. The groundnut flower had no shortage of pollen in all the varieties studied. There were over 8000 pollen grains per plant of very high viability. The only problem that may arise is the pollination process. Only about 50 percent of the flowers develop pegs indicating that in half the flowers produced, pollination or fertilization was not achieved. The location of the stigma was observed to be slightly above the anthers. This can prevent natural self-pollination. The crop cannot rely on cross-pollination, A low level of natural crosspollination of less than 2 percent has been reported (Culp et al, 1968). It has also been found that manual pollinations resulted in more pegs being produced than when groundnut flowers were left undisturbed (Lim and Siegfred, 1^84). Inadequate pollination may, therefore, cause the low peg formation.
The development of pegs into pods did not always follow peg formation. Only one-third of the pegs reached maturity. The failure of pegs to develop into pods was largely due to the abortion of the developing kernels. Unfavourable temperature and moisture regimes following fertilization, nutritional deficiencies, especially calcium and the failure of double fertilization can result in the abortion of the young kernel (Ono and Ozaki, 1974; Shibuya and Suzuki, 1956; Singh et aly 1980; Smith, 1954). For a peg to develop to maturity there must be at least one developing kernel within it. Further losses in the yield potential was evident in the number of kernels within the pod. Abortion of the developing kernels resulted in fewer kernels being present in the pod than in the pegs. Comparisons between the distribution of the ovaries for ovule number, pegs for developing kernel number and pods for kernel number show no significant differences for the distribution of ovaries and pegs indicating that fertilization and kernel development at the early pegging stage were complete. However, differences were signi-
Peg development follows fertilization (Smith 1956). However, pollination need not result in the fertilization of ovules. Many factors can delay the growth of pollen tubes and failure of fertilization. High temperatures and soil moisture 30
THE REPRODUCTIVE CHARACTERS OF FOUR VARIETIES OF GROUNDNUTS REFERENCES
ficant on comparing the distribution of pegs and pods. Therefore further loss of the yield potential occurred after pegging. Due to the abortion of developing kernels, there were only a few pods with 3 or 4 kernels. Many pods were found with 2 kernels, Single-kerneled pods were also found when originally no ovary or peg contained only one ovule. The death of one or more fertilized ovule resulted in these pod categories. These losses in yield were found in all the varieties studied.
CULP,
T.W.,
BAILEY,
W.K.
and
HAMMONS,
R.O.
(1968) : Natural hybridization of peanuts (Arachis hypogaea L.) in Virginia. Crop Set, 8: 109-110. LlM, E.S. (1978) : A technique for pollen studies. Pertanika. I: 59-61. LlM, E.S. and SlEGFRED, J. (1984) : The flowering, pollination and hybridization of groundnuts (Arachis hypogaea L.) In press.
The varieties studied were similar in their flower production and reproductive characters up to pod maturation. In these varieties, inspite of many flowers being produced, only 15 percent of the flowers developed into mature pods. The number of ovules that developed into mature kernels were even fewer, representing only 12.7 percent of the ovules available. These losses in the reproductive potential of the crop was attributed to adverse environmental influences. Thus any improvement in environmental conditions can bring about yield improvement up to the limits of the basic fertility which is about 6 times the present yield obtained. The consistency in which all varieties suffer losses at each stage of reproduction suggest that the environmental factors greatly influence the outcome of the crop. Therefore, it is not surprising that inconsistent results have been obtained in field trials. From the results it is evident that conditions that can improve pollination and reduce abortion can result in large gains in yield improvement. The manipulation of planting dates to coincide with favourable conditions, supplementary irrigation and the supply of adequate nutrients are factors to consider.
ONO, Y. and OZAKI, K. (1974) : Effect of temperature on pod development and yield of groundnut plants. Proc. Crop Set Soc. Japan., 43: 242-246. SHIBUYA, T. and SUZUKI, M. (1956) : Morphological
and physiological studies on subterranean fructification of legume crops - occurrence of abortion of fertilized seed in peanut. Proc. Crop Sci. Soc, Japan, 25: 17-18. STNGH, S U R J I T , LIM, E.S. and R A J A N A M A R T H A -
LINGAN. (1980) : Effects of lime and its placement on the growth and yield of groundnuts Arachis hypogaea L.). Proc. Legumes in the Tropic 1979, Univ, Pertanian Malaysia, pp 379-388. SMITH, B.W. (1964) : Arachis hypogaea L. Reproductive efficiency. Amer.J.Bot., 4 1 : 607-616. SMITH, B.W. (1956) : Arachis hypogaea L. Normal megasporogenesis and syngamy with occasional single fertilization. Amer. J. Bot., 43: 81-89.
(Received 26 March, 1984)
31
Fertanika 7(3), 33-37 (1984)
Growth, Mortality and Recruitment Patterns of Amblyrhynichthys truncatus (Bleeker) in Paya Bungor, Pahang MOHD. AZMI AMBAK
Department of Aquaculture and Fish Biology Faculty of Fisheries and Marine Science Universiti Pertanian Malaysia, Serdang, Selangor, Malaysia. Key words. Growth; mortality; recruitment. RINGKASAN
Kertas ini bermaksud untuk mendapatkan parameter-parameter pertumbuhan, kematian dan corak rekrutmen Amblyrhynichthys truncatus dengan menggunakan kaedah komputer untuk penganalisisan data frekuensi panjang (ELEFAN I & II). Didapati bahawa spesies ini boleh mencapat usia empat tahun dengan parameter-parameter pertumbuhan berikut: L°°=29.5cm, K=0A25 dan to = —0,41989. Walaupun kadar kematian semulajadi adalah sama dengan spesies lain di dalam tasik tersebut, tetapi kadar kematian penangkapan dan kadar eksploitasi adalah agak tinggi. Ikan ini senang ditangkap dengan menggunakan pukat tiga lapis dan penangkapan penuh berlaku pada saiz 18cm (panjang) dan purata panjang tangkapan pertama ialah 17.8cm. Terdapat satu musim rekrutmen yang kemuncaknya ialah pada bulan Januari. SUMMARY
This paper attempts to determine the growth, mortality and recruitment patterns of Amblyrhynichthys truncatus by using a computer-based method for the analysis of length-frequency data (ELEFAN I & II). It is shown that this species has an approximate life span of four years with the following growth parameters; L0O=29.5cm, K=0A25 and - -0,41989. While natural mortality (M = 1.04) is comparable to other species in the lake, fishing mortality (F - 4,15) and exploitation rates are found to be relatively high. This fish is highly susceptible to trammel nets with full retention occuring at 18cm length while the mean length at first capture is 17,8cm. There appears to be a single recruitment season with a peak in January.
INTRODUCTION
development strategies can be proposed. Thus a study was conducted by a research team from UPM from January to December 1982. With the exception of 2 papers published by the team recently (Ambak et at., 1983; Fatimah et al., 1983), no other information is available.
In many countries, freshwater bodies are being exploited for domestic and industrial purposes, i.e. mainly irrigation and power supply. In Malaysia, besides water and power supply, greater emphasis is now being placed on further development and utilization of the water bodies for fisheries related purposes such as aquaculture and recreational fishing.
Ambak et al. (1983) found that the most dominant fish species in Paya Bungor is Amblyrhynichthys truncatus. This paper describes the state of this stock and its population dynamics.
One of the areas being proposed for recreation and cages culture is Paya Bungor, a lake in Pahang. Its development will be undertaken by the Pahang State Economic Planning Unit under the project "Rancangan Projek Pelancongan Paya Bungor". Before the actual development takes place, it was though that suitable studies should be carried out especially on limnology and fish population dynamics so that adequate management and
METHODS AND MATERIALS
Samples were taken twice a month for 12 months at 2 stations using gill nets and trammel nets which were set overnight. Catches from gill nets and trammel nets were treated differently. For the purpose of this paper, only catches from 33
MOHD. AZMI AMBAK trammel nets are considered* and since the sample size is small, catches for the 2 stations have been riboled. The analysis of the population is made on a quantitative, mathematical basis.
be estimated from the empirical equation developed by Pauly (1980): log 10 M =
-
0.0066 - 0.279
log 1 0 L »
+ 0.6543 log 1Q K Estimation of Growth Parameters from LengthFrequency Data
+ 0.4634 log 1 0 T
(3)
where L°° = the maximum length in cm Growth is assumed to conform to the Von Bertalanffy Growth Formula (VBGF) ie Lt = L ° o ( l - e - K ( t ' t o ) ) where Lt = length at age t
(1)
T
• Annual mean environmental temperature in °C
Using the estimate of Z and M, values of the fishing mortality, F and the exploitation rate, E are automatically computed using the formula:
L°° • theoretical asymptothic length K = growth coefficient
F
tQ = theoretical age at length zero
E
According to Gulland (1983), this formula fits most of the observed data on fish growth. Only length data grouped in class intervals for each month are used. Since there are 2 sampling dates for every month, the monthly dates are set on the 15th. Analysis of the length frequency date for growth was done using a computer programme, ELEFAN 1 (Pauly et a/., 1980). This programme is basically a modification of the "Petersen method" which is based on modal progression in consecutive length-frequency histograms.
= number of fishes in length class
Recruitment Patterns Recruitment patterns were also derived from the ELEFAN II, using a set of growth parameters. The peaks and troughs of the length frequency data will reflect the seasonality of recruitment pattern (see Pauly et a/., (1981) for actual derivation of recruitment pattern).
a given
= time needed to grow through a length class
t
= relative age (ie when t
(5) ~Z
This gives biased estimates since fishing mortality, and therefore total mortality, is not constant. Pauly (pers. comm) has modified the ELEFAN II programme to'give a more realistic selection pattern. This modified programme was used to construct the selection pattern.
(2)
At
(4)
Every fishing gear has its own selectivity. The selection parttern for tramnel net can be obtained, by plotting the proportion of fish at each length entering the net and are retained, against length. Thus, selection patterns can be generated from the length-converted catch curves. In the original "ELEFAN II programme'*, selection patterns were contructed by assuming total mortality, Z to be constant throughout the whole size or lifespan of the fish (i.e. the straight descending portion of the catch curve can be projected backwards).
Using the growth parameters extracted from ELE FAN 1, the length frequency data was analysed for estimation of total mortality and related parameters using ELEFAN II (Pauly et ah, 1981). This programme converts the data into a catch curve with the relationship:
Where N -
Z- M
Selection Patterns
Estimation of Mortality Parameters from LengthFrequency Data
loge (N/At) = a + bt 1
-
RESULTS AND DISCUSSION and
=0) Growth
Equation (2) has the form of a liner regression where the slope, b with sign changed, represents the total mortality, Z. Natural mortality M, can
Length frequency data is shown in Fig. I and the restructured version is presented in Fig. 2.
•Gill net data are misleading since there is size selection;samples are therefore not truly representative of the population. 34
GROWTH, MORTALITY AND RECRUITMENT PATTERNS OF AMBLYRHYNICHTHYS TRUNCATUS When seeded values of K, Boo and starting points are entered, the programme provides the quantitative assessment of the growth parameters as follows: L n o significant changes were observed to have occurred in the fruits.
and
Changes in pH, oxalic acid, total soluble solids (TSS), and total sugar content of unripe fruits are shown in Table 1.
The TSS of the fruits at all storage temperaremained rather consistent. It fluctuated within a narrow range of 8.6 to 9.1 at all storage intervals.
tures
The pH ranged from 3.6 to 4.1 during storage ai the various temperatures, with no significant changes being detected.
T h e v a l u e s f o r t Q t a I g u g a r c o n t e n t dec reased slightly during storage, but was insignificant, regardless of storage temperature.
TABLE 1 Effect of storage temperature on the pH, oxalic acid, total soluble solids, and total sugar content of unripe carambola fruits. Storage period (wk)
Temp. (°C)
0
1
3
5
3.6 bc
4.0 b c
4.0 a b
3 ,6C
10
3.6*
4.1*
4.0*
3 .7 a
15
b
4.1*
3 9
a
4.1*
4.1
20
3.6
3.6
7
5
ab
3 .7*
3.8 bc — b
-
Oxalic acid (% x 100)z 5 10 15 20
29* 29* 29* 29*
5
8.6
a
8.7*
10
8.6*
15 20
18* 17 b 17 b 17 b
22 b
21b
20 b 20 b 20 b 18 b
2 1 ab 22ab
-
-
8.6*
8.6*
8.4*
8.0*
8.7*
8.5*
—
8.6*
8.5*
9.1*
8.6*
-
8.6*
8.2*
8.6*
-
-
Total soluble solids (%f
Total Sugar content (%)z 5 10 15 20
7.1a
7.0a
6.7a
6.5 a
7.1*
6.5
b
6.9
a
6.7
b
7.0
a
6.7
a
6.6*
6.6
b
6.1
b
7.1* 7.1*
6.7* —
-
Mean separation across columns by DMRT at 5% level. Means with the same letter are not significantly different from one another. 41
CX. WAN AND P.I . LAM The pH, oxalic acid, TSS and total sugarcontent values of ripe fruits obtained indicated that no significant changes occurred during storage for all the temperatures studied (data omitted) Additionally, the parameters measured above were not significantly different from the unripe fruits. Sealed bags were effective m retaining the green colour of the carambola fruit. The unripe fruits remained green, whereas the control (fruits without any packaging) and fruits in perforated bags turned yellow after 1 week in storage at 20°C. The fruits in sealed bags tasted normal. The unripe fruits turned completely yellow after 9 days when the sealed bags were left open at 20°C in normal atmosphere, thus indicating that ripening was not permanently inhibited. There were no major differences in colour change between the control and fruits in perforated bags.
Unripe fruits could be kept for 1 to 3 weeks in sealed bags, and than for another 1 week when the bags were opened. Ripe fruits in -sealed bags, on the other hand, when opened also remained good for 1 week, but the percentage of diseased fruits was much higher. The unripe and ripe fruits changed to an orange colour when exposed to normal atmosphere indicating that they would ripen on removal from storage. The CO2 concentration of the atmosphere in the sealed bags containing the unripe and ripe fruits was observed to be markedly different as storage time progressed (Fig. 1). (A)O2 18 _ • ripe A unripe _ 17
LSD 5%
I
16 \ A
A
14 13
Ripe fruits stored in perforated bags showed the greatest percentage of disease infection after 1 and 3 weeks in storage (Table 2). There was no significant difference between the control and fruits in sealed bags after 1 week in storage. However, after 3 weeks the percentage of diseased fruits in control increased significantly compared to that of sealed polyethylene bags. The fruits in sealed bags, both ripe and unripe, were less infected than the rest after 3 weeks in storage.
12 5 4
-(B)CO2 I
3
— A
- •
2 1
(C)C2H4
I
80 > c ~
70 60 50 2
TABLE 2 Percentage of diseased fruits in sealed and perforated bags at 20°C. Storage Period (Weeks) 1
3
Diseased Fruits (%)z Treatment Ripe
Unripe
Control
13 c
6 b
Sealed
19 c
0 b
Perforated 56 b
6 b
Control
!100 a
100 a
56 b
25 b
Perforated 100 a
100 a
Sealed
z
Mean separation within columns and sets by DMRT at 5% level. Means with the same letter are not significantly different.. NA = ttot available as fruits decayed.
4
6
8
10
12
DAYS AT 20 °C
Fig. 1 Percent CO%, and nl/1 sealed nonp erf orated polyethylene bags containing ripe and unripe fruits.
The CO2 concentration deceased from 4% to approximately 2% for unripe fruits, and from 4.5% to 2% for ripe ones on the 13th day at which time the experiment was terminated due to decay of the fruits. There was no observable difference between CO2 production and fruit ripeness. No sharp change in CO9 evolution was detected.
The concentration of 0 2 and C 2 H 4 in the sealed bags containing the unripe and ripe fruits was found not to be markedly affected by time or stage of ripeness. The O2 content initially increased and then gradually decreased. The
BIOCHEMICAL CHANGES, USE OF POLYETHYLENE BAGS, AND CHILLING INJURY OF CARAMBOLA and black, Cercospora rot were commonly seen in both ripe and unripe fruits when stored for another 7 days at 20°C- The occurrence of fungi attack was aggravated by the presence of dried calyxes at the stem-end. These should be removed to minimise diseases developing at the stem-end. Chilling injury though minor, began to develop in the unripe fruits, but not in the ripe fruits.
increase in O 2 content observed could probably be due to a high respiration rate of the fruit initially. This created a difference in concentration inside the bag and that of the outside atmosphere. As a result, O 2 diffused into the polybag from the outside atmosphere. The level of C 2 H 4 showed a fluctating pattern with no distinct peaks being observed. All the fruits, ripe and unripe, remained physically good, well coloured and firm with no visible signs of diseases up to 7 weeks in storage at 5°C (Table 3). Unripe fruits stored for 1 and 3 weeks at 5°C continued to ripen when they were transferred to 20°C for another 7 days
Chilling injury was distinct in the unripe fruits after 7 weeks at 5°C. All the ribs of the fruits were black, and there were dark brown patches on the skin. These brown patches were shown as discolorations and were present only on the surface of the skin. They were not diseases as such as seen at higher temperatures. The fruits were dull green or turned to a dull yellow colour on further storage for 3 days at 20°C. The ripe fruits after 3 days storage at 20°C were still good and firm without any chilling injury being seen. Some diseased dark spots caused by Cercospora species were present. Also, some ribs of the fruits turned black due to shrivelling.
Unripe fruits could be stored for 3 weeks at 5°C, followed by 1 week at 20°C, making a total postharvest storage life of 4 weeks. No chilling injury symptoms were observed in either the ripe or unripe fruits. The ribs of unripe fruits stored for 5 weeks at 5°C were dark brown
TABLE 3 Percentage of diseased fruits, and colour index changes of ripe and unripe fruits stored at 5°C. Storage Period (wk) 1
Duration at 20°C (day) 0 7
3
5
7
9
Diseased fruits (%)Y Ripe 0 15 cd
Color- indcx Y z
Unripe
Ripe
Unripe
0 c
6 be
2 de
0 c
7 a
5 be
__
7 a
14
_
0
0 d
0c
6 c
3 d
7
30 bed
5 c
7 ab
6 b
0
0 d
0 c
5 c
2 de
7
100 a
95 a
7 a
7 a
0
0 d
0 c
5 a
1 de
3
60 b
15 c
6 c
3 d
0
30 bed
15 c
6 c
2 dc
3
50 be
30 b
7 ab
4 c
100 a
Means of treatment with the same letter within each column is not significantly different from one another at the 5% level according to DMRT. Colour index score : 1 = green, 2 - green with trace of yellow; 3 = more green than yellow; 4 = more yellow than green; 5 * yellow with green rib; 6 = yellow; 7 = yellow with some brown flecks;'8 • brown.
43
C.K. WAN AND P.F. LAM starch. The total sugars found by Chan and Heu (1975) in carambola added up to 3.19% of the fresh weight of the fruit. The total sugars ranging from 6.1 tp 7.5%, of the cultivar used in this study is, therefore, twice that reported by the above researchers.
No chilling injury developed in ripe fruits after 9 weeks storage at 5°C. Generally, the ribs of fruits were shrivelled and brown in colour. There were some diseased dark spots present on the fruits. Diseases became m o - severe on further storage of 3 days at 20°C although the fruits remained firm. Unripe fruits exhibited chilling injury. The symptoms were similar to those shown in fruits stored for 7 weeks at 5°C. Fruits were firm and were either dull green or brownish green in colour.
Ripe and unripe fruits in perforated bags and controls senesced at the same rate. Both were 100% diseased after 3 weeks in storage (Table 2). This was significantly higher than the fruits stored in sealed bags. Only 56% of the ripe fruits in sealed bags and 25% of the unripe fruits were diseased. Furthermore, the green colour of the fruits was maintained when stored in sealed polyethylene bags indicating that their storage life could be prolonged. Sealed bags have also prolonged the storage life of bananas (Scott et, al., 1970; 1971) and avocados (Chaplin and Hawson, 1981) by retarding ripening due to alteration in the atmosphere around them.
DISCUSSION Vines and Grierson (1966) reported that the pH in carambola rose from 2.3 in the green fruits to 3.8 in the ripe fruits. In this study, no significant increase in pH was observed at the various storage intervals regardless of the temperature the unripe fruits were stored in (Table 1). This, perhaps, was due to the fact that the unripe fruits used had already begun to ripen since they had passed the green stage.
Initially the CO2 content in the sealed bags was high and when the respiration of the fruit reached a steady state, the CO, content decreased to a constant level. (Fig. 1). Normal atmospheric air contains about 0.03% CO 2 , and the concentration in the bag was found to vary from 2.5 to 4.5%. The COg concentration was, therefore, approximately 80 to 150 times that found in normal atmosphere. This range in CO 2 concentration lies between the range of 3 to 9% as reported by Duvekot (1961) and Moiseyeva (1960) in the internal atmosphere of apple packages. Similarly, they found that packaged apples have a longer shelf life than unpackaged apples.
Total titratable acid decreased during ripening which is similar to other fruits such as 'calamansi' citrus (Data et aL, 1975), mango (Morga et al., 1979), and papaya (Broughton, et al., 1977). This is similar to the observation made by Grierson and Vines (1965). The decrease in total titratable acid was probably due to it being metabolized in the Krebs^tricarboxylic Acid Cycle as reported by Vines and Grierson (1966). The TSS content did not change significantly when the fruits ripened from the green to the orange stage during storage at all temperatures. In contrast, mango exhibits a large change in TSS from 7 to 19% (Morga et al., 1979). The mature green carambola fruit, therefore, did not show a significant increase in TSS during ripening after harvest. This was probably because of the absence of starch in the fruit. In this respect it resembles melons. Pratt et al. (1977) reported that the soluble solids in mature melons did not increase because sugar accumulation from the hydrolysis of starch was not possible. Data ex at. (1975) showed that TSS increased with storage time in small and medium green mature 'calamansi* citrus fruits. In the citrus the stored starch was converted to sugars during storage.
The O,, content fell to approximately 15%. This is 6% lower than the noral atmospheric concentration of 21%. The modified gaseous composition of 2.5 to 4.5% CO and 15% O 2 in the polyethylene bags would re&uce the respiration rate of the unripe fruits. It also maintained the chlorophyll content of the skin of the fruits for 2 to 3 weeks at 20°C. The small deviations in CO, and O 2 concentrations at equilibrium was similar to the results of Chaplin and Hawson (1981). They found that the levels of gases in bags of avocados at ambient temperature were not different whether stored for 5 or 10 days. On the other hand, Pantastico etal (1970) found that 1% O 2 o r l 0 % a n d 15% CO2 produced irreparable peel injury and impaired the ripening process in bananas. But the levels of these two gases in the bags of carambola fruits in this study were within the range reported by Pantasico et al. (1970). They also reported that ripening was induced earlier in 10% and 15% C 0 0
Total sugar content did not change significantly regardless of temperature. The percentage of sugar in carambola is rather low when compared to that of bananas.. Bananas (CSIRO, 1972) have approximately 1% in the mature green stage and 16% in the ripened stage. The marked increase is due to the hydrolysis of starch to sugars as the green mature bananas have about 22% 44
BIOCHEMICAL CHANGES, USE OF POLYETHYLENE BAGS, AND CHILLING INJURY OF CARAMBOLA temperature. The fruit will ripen when they are removed before 5 weeks in storage at 5°C and placed at 20°C.
than in 5% CO 2 level probably because of CO 2 injury Dull et al. (1967) showed that decreased O 2 and increased CO 2 concentrations had no obvious effect on pineapple quality. They recommended that there was no advantage on quality maintenance by manipulating the concentration of these two atmospheric gases. However, we found that it could extend the storage life of the carambola fruits.
REFERENCES AOAC. (1975): Methods of Analysis. Washington D.C. 12th Edition. Biale% J.B. (1960): The postharvest biochemistry of tropical and sub-tropical fruits. Advance Food. Res. 10:293-354. BROUGHTON, W.J., HASHIM, A.W. SHEN, T.C and TAN. I.K.P. (1977). Maturation of Malaysian fruits. I. Storage conditions and ripening of papaya Carica papava L. cv. 'Sunrise Solo'). MARDI Res, Bull. 5:59-72.
Chilling injury of unripe carambola fruits occurred after 5 weeks in storage at 5°C (Table 3). The degree of injury was slight but became more severe as storage time lengthened. This is similar to bananas as reported by Pantasico et al. (1967). They showed that the portion near the blossom end, which was less mature than the bigger stem end, was more susceptible to chilling injury. Ripe carambola fruits are not effected by chilling injury at 5°C. Carambola fruits which are unripe could only be stored for 5 weeks or less at 5°C. If a longer storage period at 5°C is desired, then only ripe fruits should be used.
CHAN. H,T., and HEU. R.A. (1975): Identification and determination of sugar in star fruits, sweetsop, green sapote, jackfruit, and wiapple, /. Food Sci. 40: 1329-1330. CHAPLIN, G.R., and HAWSON. M.G. (1981): Kxtending the postharvest life of unrefrigcratcd avocado (Persea americana Mill.) fruit by atorage in polyethylene bags. Scientia Hort 12: 219-226, CSIRO, (1972): Banana ripening guide. Division of Food, Res Circulat No ',, Australia.
The development of chilling injury symptoms was similar to those exhibited by avocado fruits (Eaks, 1976). Eaks (1976) demonstrated that avocado fruits do not soften or show symptoms of chilling injury when they are stored for 5 weeks at 5° or 0°C. However, after transfer to 20°C for I week or longer they developed chilling injury and the sensitivity increased as the exposure period was lengthened.
D A T A , E.S., M E N D O Z A , D.B. and PANTASTICO, Jr. B.
(1975), Storage of Calamansi fruits (Citrus mitis Blanco). I. Chemical changes. Philippine Agri. 9: 119-125. D U L L , G.G.
YOUNG,- R.K.
and
BIALE, J.B.
(1967:
Respiratory patterns in fruits of pineapple, Ananas Cosmosus, detached at different stages of development. Physiol. Plant. 20: 1059-1065. DUVEKOT, W.S. (1961): Storage of apples, pears, under plastics. In. International Inst. Refrig. Bull. Annex.
CONCLUSION The pH, titratable acid, total soluble solids, and total sugar content changes were not significantly different during storage at the temperatures studied. No starch was detected in the mature ripe fruits. Carambola should, therefore, be harvested at the ripe stage and then stored. Ripe fruits will give a better quality and colour than the stored unripe fruits.
EAKS, I.L. (1976): Ripening, chilling injury, and respiratory response of 'Hass' and Fuerte' avocado fruits at 20°C following chilling. J. Amer. Sco. Hort. Sci. 101:538-540. GRIERSON, W., and VINES, H.M. (1965): Carambolas for potential use in gift fruit shipments. (Proc. Florida State Hort, Soc. 78: 349-353. LAM, P.F. and LYE, T.T. (1982): Durian storage ;Tt lowtemperatures. MARDI, Unpublished.
There was no difference in the storage life of fruits packed in perforated polyethylene bags and control. Fruits, particularly the unripe ones, could be stored longer in sealed polyethylene bags. Additionally, the green colour of the unripe fruits could be maintained longer. The fruits ripened and turned completely yellow in colour when the bags were opened.
LYOMS, J.M. (1973): Chilling injury in plants. Ann. Rev. Plant Physiol. 24: 445-466. MANDOSA. D.B.,
PANTASTICO, Jr, B. and
JAVIER,
F.B. (1972): Storage and handling of rambutan (Nephelium lappaceum L,) Phillippine Agri 55 : 322-332.
Unripe fruits are susceptible to chilling injury when stored for 5 weeks at 5°C. The severity is increased as storage time is prolonged at this
MOISEYEVA, N.A. (I960): The storage of apples in plastic films. In Studies on storage of fruits and vegetables. Int. Inst. Refrig. Bull. Annex 1960. 45
C.K. WAN AND P.F. LAM MORGA,
N.S., LUSTRE,
BALAGOR.
A.O. TUNAC, M.M.
SCOTT, KJ., BLAKE, G., STRATCHAN, B.C., TUGWELL, and MCGLASSON.W^B. (1971). Transport of bananas at ambient temperatures using polyethylene bags. Trop. Agri. (Trinidad) 48 : 245-254.
A.H. and S O R I A N O , M.r. (1979):
Physico-chemical changes in Philippine 'carabao' mangoes during ripening. Food Chem. 4 : 225-224.
GANDANEGARA, S. (1974): Effect of temperature on the storage life of bananas held in polyethylene bags with ethylene absorbent. Tropical Agric. (Trinidad) 51 : 23-26.
PANTASTICO, Jr. B., G R I E R S O N , W. and SOULE, J.
(1967): Chilling injury in tropical fruits. I. Bananas (Musa paradisiaca var. sapientum cv. Lacatan). Proc. Amer. Soc. Hort. Set Tropical Region 11 :
82-91. MENDOZA
SUBRAMANYAM, H., KRISHNAMURTHU, S. and PARKIA, H.A.B. (1975): Physiology and biochemistry of mango fruit. Adv. Food Res. 21 : 223-305.
D.B. ESPINO. V.C. BONDAD N.D. and
CALARA. E.R. (1970): Regulation of fruit ripening. I Refrigerated controlled atmosphere storage. Philippine Agri 54 : 120-134. PRATT.
VINES, H.M., and G R I E R S O N , W. (1966): Handling and
physiological studies with the carambola. Proc. Florida State Hort Soc. 79-: 350-355.
H.K., G O E S C H L , J.D. and MARTIN, F.W.
(1977): Fruit growth and development, ripening, and,the role of ethylene in the 'Honey Dew' muskmelon. /. Amer. Soc. Hort. Set 102 : 203-210. SCOTT.
K.J., Me GLASSON. W.B. and
VON LOESECKE, H.W. (1949): Bananas : Chemistry, physiology and technology. N. York Intersci. Pub. Inc.,
ROBERTS.
(Received 21 January, 1984)
E.A. (1970). Potassium permanganate as an ethylene absorbent in polyethylene bags to delay ripening of bananas during storage. Australia J. Expt. Agri Animal Husbandry 10 : 237-240.
46
Pertanika 7(3), 47 48(1984)
Perineal Urethrostomy in a Dog with a Severed Penis W.T. WONG
Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine and Animal Science, Universiti Pertanian Malaysia, Serdang, Selangor, Malaysia. Key words:
Perineal urethrostomy; dog. RINGKASAN
Satu laporan tentang kejayaan merawat seekor anjing yang zakarnya luka parah. Prinsip dan teknik perineal uretrostomi pada anjing dibincangkan. SUMMARY
The successful surgical management of a dog with a severed penis is reported. The principles and technique of perineal urethrostomy in the dog are discussed. INTRODUCTION
Anaesthesia was induced with thiopentone sodium and maintained with oxygen and halothane. A lactated Ringer's intravenous drip was also set up. Examination of the preputial cavity with the aid of a vaginal speculum failed to locate any remnants of the penis. A ventral midline incision was made anterior to the scrotum and the preputial cavity exposed. Oedema and contusion of the surrounding soft tissue were evident. The preputial mucosa was torn at numerous sites and the stump of the penis was observed protruding I mm from the caudal reflection of the preputial mucosa. The end of the stump had a clean, perpendicular cut surface with the urethral orifice visible. The urethra was catheterised and 250 ml of urine aspirated.
Trauma to the canine penis is not a common problem except during sexual activity when injury may be inflicted by other dogs or irate owners (Wilson, 1975). Thus at this Veterinary Teaching Hospital, common surgical manipulations of the penis per se have been confined to excision of transmissible venereal tumor lesions and correction of paraphimosis. Bite wounds in hunting dogs inflicted by wild boars are presented occasionally. It is the objective of this paper to present a case of traumatic penile amputation in a dog. HISTORY
A one-year-old male dog of mixed breed was presented with a history of having returned home the evening before with profuse bleeding from the prepuce. The owner had attempted to control the bleeding with pressure on the prepuce. A bitch in the neighbourhood had been noticed in oestrus.
An enlargement of the urethral orifice on the penile stump was made by spatulating the urethral mucosa and suturing it to the corpus spongiosum. The tears in the preputial mucosa were repaired and the skin incision closed with non-absorbable sutures. The dog was also castrated.
RESULTS
The following morning, it was noticed that whenever the dog made an effort to urinate, the inguinal region swelled and was warm. Urine seepage into the subcutaneous space had occurred and emergency surgery was indicated. It was decided to carry out a perineal urethrostomy rather than a scrotal urethrostomy because of the risk of poor healing associated with the trauma at the prepuce.
The dog was depressed on presentation. The bleeding from the prepuce had stopped. Large blood clots filled the preputial cavity and the penis was not palpable. Examination under anaesthesia and surgical intervention were scheduled pending results of a complete blood count and blood urea nitrogen (BUN). The results revealed a hematocrit of 28% and a BUN of 32.6mg%. 47
W.T. WONG
The use of an indwelling urinary catheter to maintain a patent urinary passage while the urethrostomy site heals is a valicl consideration. However, care should be exercised in choosing the size of the catheter because overstretching of the urethral wall can produce stricture (Weaver and Schulte, 1962).
The dog was placed on dorsal recumbency to expose the stump of the penis for catheterization. Another 220 ml of urine was withdrawn. A 3 cm midline skin incision was made between the anus and the scrotum. The urethra was identified by palpating for the catheter. After separating the fibers of the bulbocavernosus muscle, the urethra was incised. The mucosa together with part of the corpus spongiosum were sutured to the skin with care taken to achieve good apposition with the skin. A scrotal ablation was also performed. An indwelling catheter was left in place. The dog was maintained on a systemic antibiotic. To prevent self-inflicted trauma to the urethrostomy site, an Elizabethan collar was used and a tranquillizer given for 7 days. The dog recovered uneventfully and when examined 8 weeks later did not show any evidence of stricture or urine scald.
From the history and clinical examination of the penile stump, it is highly probable that the penis had been amputated with a sharp cutting edge. However, the question as to whether this was iatrogenic or accidental remains unanswered. REFERENCES BROWN, S.G. (1975): Surgery of the canine urethra. Vet. Gin. North Am. 5 : 457470. SMITH, C.W. and SCHILLER, A.G. (1978): Perineal
urethrostomy in the cat: a retrospective study of complications. J. Am. Anim. Hosp. Ass. 14 : 225228.
DISCUSSION
Urethrostomy in dogs is not a commonly performed procedure because of the inherent dangers of stricture and urine burns (Brown, 1975; Yoshioka and Carb, 1982). In a survey of the surgical cases in 78 small animal practices in California in which a total of 10,088 operative procedures were performed, no urethrostomies in dogs were recorded (Vasseur et alt> 1981). It is impossible to draw any conclusion from the one case reported here, but from this experience and those reported in the literature, it would appear that urethrostomics in dogs can be rewarding if certain important guidelines are followed. These include minimal tension at the urethrostomy site, accurate apposition of urethral mucosa to skin margins and the use of collars to prevent licking and selfmutilation (Yoshioka and Carb, 1982; Smith and Schiller, 1978).
VASSEUR, P.B., B E R G E R , B. and LEIGHTON, R.L.
(1981): The volume and distribution of surgical cases in 78 small animal practices in California. /. Am. Anim. Hosp, Ass. 17 : 161-166. WEAVER, R.G. and SCHULTE. J.W. (1962): Experi-
mental and clinical studies of urethral regeneration. Surg. Gyn. Obst. 115 : 729-736. WILSON, G.P. (1975): Surgery of the male reproductive tract. Vet. Gin. North Am. 5 : 537-550. YOSHIOKA, M.M. and CARB. A. (1982): Antepubic
urethrostomy in the dog. /. Am. Anim. Hosp. Ass. 18:290-294. (Received 9 June. 1984.) -
48
Pertanika 7(3), 49-52 (1984)
Factors Affecting Ovipositional Behaviour of Scutellista cyanea, an Egg-parasitoid of Hemispherical Scale A. GHANI IBRAHIM Department of Plant Protection, Faculty of Agriculture Universiti Pertanian Malaysia Serdang, Selangor, Malaysia. Key words:
Scutellista cyanea; Saissetia coffeae,egg- parasitoid opposition; adult longevity. RINGKASAN
Scutellista cyanea ialah serangga parasitoid telur teritip termasuk Skala hemisfera Saissetia coffeae. Pemangsa bertelur di dalam teritip dewasa. Suhu mempengaruhi bilangan telur yang dikeluarkan oleh parasitoid dan juga jangka masa hidup dewasa. Pada 20°C jangka hidup dewasa ialah purata 80 hari tetapi pada 28°C, hanya 30 hart sahaja. Sebaliknya bilangan telur yang dikeluarkan bertambah dengan kenaikan suhu. Dalam perbandingan di antara dua saiz teritip iaitu yang ukuran panjang lebih daripada 3.5 mm dan yang kurang daripada 2.5mm, keputusan menunjukkan perbezaan yang bermakna (pK0.05) didapati kerana bilangan serangga parasitoid yang keluar dari teritip bersaiz lebih daripada 3.5mm adalah banyak. Hubungan di antara ukuran lebar kepala dewasa parasitoid dengan jangka hidup dan bilangan telur yang dikeluarkan ialah r=0.90 dan r=0.93. SUMMARY Scutellista cyanea Motschulsky is an egg parasitoid of many coccids, including the hemispherical scale, Saissetia coffeae. The adult female parasitoid oviposits in gravid scale, S. coffeae. Ambient temperature influences the number of eggs deposited and adult longevity of the parasitoid. The life-span of the adult parasitoid was found to be reduced with an increase in temperature; at 20°C longevity it was 80.0 days while at 28°C it was only 30 days. On the other hand, an increase in temperature within limits would increase the total number of eggs deposited by the parasitoid. In a comparison of two sizes of host-scale i.e. scale >3.5mm in length and
s
Z 30O
0
E»
ADULT LONGEVIT
PRODUCTION Scales >3.0mi
6
-7 -8 HEAD WIDTH;SCYANEA
-9
Fig. 2. The relationship between head width, adult longevity and total egg production of S. cyanea.
1
2
3
A
5
6
7
8
tig. 4. Patterns of emergence of S. cyanea from different length of gravid S. coffeae at 26°C. (A) Alternating of big and small scales, (B) alternating of small and big scales, (C) consecutively big scales and (D) consecutively small scales. Figures above bar denote the number of emerged parasitoids.
Fig. 3. The pattern of daily oviposition of S. cyanea at different constant temperatures for 25 days. Based on 20 individuals at each temperature.
51
A. GHANI IBRAHIM TABLE 1 Mean number of S. cyanea adults emerging from different sizes of S. coffeae at constant temperatures of 26 C for eight consecutive days. radio
Sex
Female parasitoid offered
Mean + s.e.
LSD (3.14)
Big scale alternating with small scale
3.4 * 0.79
b
0.7 *
Small scale alternating with big scale
3.3 + 0.96
b
0.65 : 1
Big scale only
8.2 + 2.8
a
0.28
Small scales only 1
:
Male
•
0.4 + 0.17
Female
'
1: 1
b
Means with the same letters 'are not significantly different at the 5% level by LSD. (Least Significant difference). REFERENCES
These findings suggest that temperature and size of gravid scales influence the rearing of 5. cyanea. Therefore, the parasitoids should be reared at 26°C on gravid scales (>3.5mm length) to ensure the emergence of a higher proportion of female parasitoids. These newly emerged female parasitoids should be released in the biocontrol of S. coffeae for they have higher egg-laying capacity and longer longevity. The effect of temperature on the parasitoids has its practical application in the temperate countries such as the United Kingdom where there is a great variation in seasonal temperatures. In temperate glasshouses, the winter temperature is so cold that it can reduce the egg-laying capacity of the parasitiods. Therefore the parasitoids should be released in the glasshouse during summer so that they have a greater egg-laying capacity and turn-over during the warm temperature.
BARBER, P. (1980) :• Studies on fecundity, longevity and settlement of hemispherical scale, Saissefia coffeae (Walker) (Homoptera: Coccidae). M.Sc. Thesis, Wye College, University of London. 49pp. CLAUSEN, P. (1940) : Entomophagous insects. N. York & London. Hill 688 pp. EL-MINSHAWY, A.M.;
SAAD, A.H: HAMMAD, S.M.
(1978) : Efficacy of the natural enemy of S. coffeae (Walker), S. oleae and Ceroplastes floriden-
sis, Comst (Homoptera:Coccidae). Z. angew. Ent 85 : 31-37. IBRAHIM. A.G. (1983) : Biological control of Glasshouse hemispherical scale. PhD Thesis, Wye College, University of London, 234 pp. LUCK, R.F. (1981) : Parasitic insects introduced as biocontrol for arthropod pests, pp 125-284. In Handbook of pest management agriculture, Vol II (ed) Pimentel. Florida. D. CRC Press, Boca Raton, 501 pp.
ACKNOWLEDGEMENTS
QUAYLE, H.J. (1911) : The black scale. Univ. Calif. Agr, Exp, Sta. Bull. 223: 1-49.
The author is indebted to Dr. M J.W. Copland of the Department of Biological Sciences, Wye College (University of London) for guidance of the research and Prof. G. Varghese (Dept. Plant Protection, UPM) for his critical comments on the manuscript. My thanks are also due to Dr. Argyrio for parasitoid culture. This work is part of a thesis submitted for a Ph.D degree to the University of London by the author who was in receipt of funding from the Commonwealth Scholarship Commission. The work was carried out under MAFF Licence PHF 64.
SAAD,A.H.;
EL-MINSHAWY, A.M.
and
HAMMAD,
S.M. (1977) : Studies on the bionomy of 5. cyanea Motschulsky (Hym: Pteromalidae). Z. angew, Ent. 83 : 155-61. SlNADSKII, Y.V. and KOZARZHEVSICAYA, E.P. (1980) : Biological protection of flowering and decorative plants. Zashch. Rast. Vredit. 10 : 21-22. (Received 25 June, 1984) 52
Pertanika 7(3), 53-58 (1984)
Assessment of Damage by the Rice Moth, Corcyra cephalonica (St.) on Different Grains at Four Levels of Moisture Content. NOORMA OSMAN Department of Plant Protection, Faculty of Agriculture Universiti Pertanian Malaysia, Serdangt Selangor, Malaysia. Key words: Corcyra cephalonica; damage assessment RINGKASAN Taksiran kerosakan oleh C.cephalonica ke atas 'millet', sekoi, beras dan padi dalam keadaan peratus kandungan kelembapan yang berlainan telah ditentukan dengan menggunakan kaedah 'count and weigh method'. Parameter-parameter yang ditentukan adalah peratus kerosakan pada bijirin, peratus kehilangan berat kering serta berat kering'fr ass' dan 'webbings'.Peratus larva yang berumur 12 ± 12 jam yang dapat meneruskan ke peringkat dewasa dan purata kala perkembangan larva ke peringkat dewasa juga ditentukan. Empat peringkat peratus kandungan kelembapan yang digunakan dalam kajian ini tidak mempengaruhi peratus kerosakan pada bijirin, peratus kehilangan berat kering serta berat kering Jras' dan 'webbings'. Padi ialah yang terkurang sekali kerosakannya; sedikit sekali larva yang dapat meneruskan ke peringkat dewasa. Peratus larva yang dapat meneruskan ke peringkat dewasa, meningkat daripada peratus kandungan kelembapan 11.1% ke 13.2% bagi 'millet', sekoi dan beras, sementara pada peratus kandungan kelembapan 14.1%, ia susut. Peratus larva yang dapat meneruskan ke peringkat dewasa pada beras yang kandungan kelembapan 11.0% berbeza dengan jelas, dibandingkan dengan beras yang kandungan kelembapannya 14.1%. Puratakala perkembangan larva pada 'millet', sekoi dan beras yang kandungan kelembapan 11.1% berbeza dengan jelas dibandingkan dengan kandungan kelembapan 14.0%. SUMMARY Assessment of damage by C.cephalonica on millet, sorghum, milled rice and padi at four moisture contents was determined using the count and weigh method. The parameters determined were percent damaged kernels, percent dry weight loss and dry weight offrass and webbings. The percent survival and the average development period of 12 ± 12 -hr- old larva to adult were also determined. The four moisture contents used in this study did not influence the percent of damaged kernels, percent dry weight loss or the dry weight offrass and webbings. Rough rice was the least damaged of all the four grains; few larvae survived. The percent of larvae that survived to adult showed an increase from 11.1% MC to 13.2% MC for millet, sorghum and milled rice while at 14.1% MC, it decreased. For milled rice, the percent of larvae that survived at the lowest MC was significantly lower than at the highest MC. The development period in millet, sorghum and milled rice was significantly lower at the lowest MC. were totally undamaged. Corcyra cephalonica is an external feeder and thus hidden infestation is not a concern. t C. cephalonica has been reported to infest many types of stored products, from different parts of the world (Hodges 1979). However, few studies have been carried out to evaluate losses incurred by this pest. The present study was conducted to determine the quantitative loss caused by C. cephalonica in millet, sorghum, milled rice and padi store at 30 + 2°C and various moisture contents.
INTRODUCTION
Loss assessment studies on the different stored grain insects have been reviewed by Adams (1976). Three methods of loss assessment were outlined by Adams and Schulten (1976) - the standard volume and weight method, determination of the percentage insect-damaged grain and its conversion into a weight loss using a multiplication factor, and the count and weigh method. The present study utilised the count and weigh method which assumed that undamaged grains 53
NOORMA OSMAN
MATERIALS AND METHODS
drains
r Insects
Whole grains of the cereals were used. Broken grains and foreign materials were removed by using sieves of appropriate sizes for the different grains and by hand sorting. The grains were adjusted to the required moisture content (MC). Grains with an original MC higher than the required MC were air dried by spreading on paper at ambient conditions in the laboratory and the MC monitored using a Motomco moisture meter until the desired MC was reached. If the MC had to be increased, water was added to grains in a gallon jar which was then closed and shaken. The jars were shaken daily for two weeks to assure uniform conditioning/mixing. One hundred grams of each grain type that had reached the required MC was kept in a pint jar and stored in relative humidity (RH) chambers, controlled to maintain the appropriate equilibrated relative humidity. Jars were kept in the RH chambers for a week before larvae of C.cephalonica were transferred. Each grain type was replicated six times three for infestation with C.cephalonica and three for the controls. Relative Humidity tio ns
with a temperature of 30 ± 2°C and a photoperiod of 14L: 10D.
and Experimental Condi-
Saturated salt solutions of magnesium nitrate hexahydrate (Mg No 3. 6H2 O), sodium nitrite (Xa No ), sodium acetate trihydrate (Na Ac. 3II2O) and potassium bromide (KBr) were used to maintain 50, 60, 70, and 80% RH, respectively (Winston and Bates 1960). The saturated solutions of each was prepared by dissolving excess salts at room temperature. These were allowed to stand for two weeks to ensure saturation before use. Each RH chamber was a 87.6 litre brown plastic container with a diameter of 45.7 cm and height of 53.3 cm. A perforated pressed board placed about 25 cm. above the surface of the solution by means of metal pegs, was used as a platform to hold the jars of grains. The chambers were tightly sealed by means of petroleum jelly between the lid and rim of the container. Once the insects had been introduced into the jars, the chambers were opened up daily for five seconds to allow for ventilation. The relative humidity in each chamber was monitored by placing in each, a portable 12.7 cm diameter Abbeon Certified Hygrometer and Temperature 'indicator (Mod. HITAB 169B). All four hygrometers were calibrated at 70 + 2% RH before use. The chambers were placed in a rearing room
Corcyra cephalonica were reared on a standard medium (Osman et at., 1983) and maintained in a rearing room at 27 ± 1°C and 68 ± 2% RH. One hundred newly hatched larvae were transferred into each pint jar containing 100 gm of the conditioned grains. After the first adult emerged, all jars were checked daily for adults. Adults were removed daily to avoid oviposition. Experimental Design A split plot design was used for this experiment. A relative humidity was randomly chosen for infestation. The three jars in that RH were infested and three were left unifested as controls. For infestion of the jars, the RH chambers were randomly selected to be in the following order :• 70%, 60%, 50%, 80%. Infestation was completed over two .days to allow time for moisture tests and handling at the end of the experiment. Measurement of Moisture Content After all adults had emerged and had been removed from each jar, MC was determined for both infested and controlled grains. To prevent unnecessary exposure of grains to ambient conditions, grains from each jar were poured into a transparent 27.9 x 22.9 cm plastic bag and tightly closed. The grains were mixed well and two 10-gm samples per jar were weighed and placed in aluminium moisture tins. A total of six samples for each treatment were measured for their MCs. A single-stage air-oven moisture determination method was used for all grains (AACC Method 44-15 1969). Millet, sorghum and milled rice were oven dried for 18 hrs at 120°C while padi was dried for 20 hrs at the same temperature. All moisutre contents were expressed as percent of wet weight. Loss Assessment Method Each jar together with its contents was weighed. The jar was then emptied and weighed again. The difference gave the weight of the contents which included whole and damaged grains, larval webbings and frass. The contents of each jar was divided into four equal samples by weight and one was analysed for loss. Grains in the sample were separated and weighed. The number and weight of both damaged and undamaged kernels were noted. The contents of
ASSESSMENT OF DAMAGE BY THE RICE MOTH CORCYRA CEPHALONICA ON DIFFERENT GRAINS. the jars for the control were handled in the same manner. Two parameters of estimating damage were used : percentage damaged kernels and percentage dry weight loss. The percentage damaged kernels was calculated by dividing the number of damaged kernels by the total number of kernels per sample. The percentage dry weight loss was determined by using a formula described by Adams & Schulten (1976: % weight loss = (UNd) - (DNu) x 100 U(Nd + Nu) Where
U = weight of undamaged Nu = number of undamaged D = weight of damaged Nd = number of damaged
Means of treatments for each type of grain were compared by using the least significant difference statistics (LSD). RESULTS AND DISCUSSION The percentage of dry weight loss, dry weight of frass and webbings and the percentage of larvae that survived to adult were lowest for all four grains at the lowest MC. The development period from 12 + 12-hr-old larva to adult emergence was the longest at the lowest MC for all the grains. Percentage Damaged Kernels, Percentage Dry Weight Loss and Dry Weight of Frass and Webbings, The MC of grains used in this study appeared to have a variable effect on the percent of insectdamaged grains (Table 1). The only significant difference detected was the percent damaged grains of millet at 12.1% and 14.1% MC (K0.05). The data on the percent dry weight loss is also shown in Table 1. It increases as MC increases for milled rice and padi while a similar trend is not seen for millet and sorghum. The percent dry weight loss is generally lower compared to the percent of damaged kernels. Unlike Sitotroga cerealella, C.cephalonica is an external feeder. There seems to have been a preference for the germ of kernels although there were kernels that were found to have parts of the endosperm damaged. The dry weight loss of milled rice is only in the range of 3 — 7% as compared to millet and sorghum which had a
range of 12.6 to 21.5%. C.cephalonica was observed to feed solely on the germ of milled rice kernels. No kernels were* found to have portions of the endosperm consumed. The percent damaged grains, percent dry weight loss and the dry weight of frass and webbings for rough rice are extremely low compared to the other three grains. The husk covering the kernels probably prevented the larvae of C.cephalonica from feeding on the germ although there were kernels that had husks slightly damaged at the tip. Moreover, the few survivors of C.cephalonica may have caused the low dry weight loss. With the exception of millet, the dry weight of frass and webbings increased from the lowest to the highest MC (Table 1). No significant differences were detected among the grains for the MC Chatterji (1952) determined that the weight loss of sorghum due to damage by C.cephalonica at 75% RH was 9.9% and the percent damaged kernels was 23.1% Sidik (1981) reported that the percent dry weight loss of milled rice due to Tribolium castaneum after 20 weeks of storage was 2.19%. This study was conducted at 29 ±1°C and 70 ± 5% RH. Percent dry weight loss by Sitophilus oryzae was 37.0% under similar conditions. The percent weight loss of padi stored for a period from 6 to 9 months due to damage by Sitotroga cerealella ranged from 4.2 — 11.9 and with 3.4 — 12.0% infested kernels in Bangladesh (Shahjahan, 1974). The amount of frass and webbing caused by C.cephalonica in our samples increased from the lowest to the highest MC for sorghum, milled rice and rough rice (Table 1) but was inconsistent for millet. The differences were not significant for any grain. Percent of 12 ± 12-hr-old Larvae that Survived to Adult and Their Developmental Periods. More larvae of C.cephalonica survived on millet and sorghum of about 13% MC (Table 2). The percentage of larval survival on milled rice increased as MC increased. Larval survival on milled rice is significantly different (P Entomology Dept., Kansas State Univer'• *y n *rA*.*.*, r* ** WlNSTON P W a n d BATES D.H. (I960): Saturated s X i o n for the control of humidity in biological research. Ecology 4(1) : 232-237.
S I I A H J A H A N . M. (1974) : Extent of damage of unhusked stored rice by Sitotroga cerealella oliv. (Lepidoptera, Gelechiidae) in Bangladesh. /. Stored Product Research 10 : 23-26.
(Received 10 February, 1984),
58
Pcrtanika 7(3), 59-65 (1984)
Conductance Measurement of Water-sorbed Activated Carbon M. BADRI, KAREN A. CROUSE and HARUN AWANG Department of Chemistry, Faculty of Science and Environmental Studies, Universiti Pertanian Malaysia, Serdang, Selangor, Malaysia, RINGKASAN Key Words: Conductance; activated carbon; capillary; sorption pore radius RINGKASAN Keknnduksian sekeping karbon yang diaktifkan telah disukat semasa ia terendam dalam air pada lima suhu yang berlainan. Perubahan kekonduksian ini mengikut masa telah dianggapkan sebagai kesan pengionan kumpulan-kumpulan berfungsi pada dinding Hang tatkala ia disebakki air. Jejari purata Hang telah dianggarkan melalui persamaan-persamaan yang diterbitkan bagi mengaitkan perubahan ini dengan kadar pengaliran air ke dalam Hang. SUMMARY
The conductance of a piece of activated carbon has been measured while immersed under water at five different temperatures. The change in conductance with time has been attributed to the ionization of the functional groups on the walls of the pores as the latter were gradually filled. The average pore radius has been estimated by using the equations derived to relate the increase in the conductance to the rate of flow of water into the pores.
INTRODUCTION
However the pores in activated carbon increase its surface area and make it an excellent adsorbant for many chemical species both in gaseous phase and in solution. In addition to the active centres due to unsaturation of the bonding orbitals of the carbon atoms at the surfaces and edges of the pores, it has been proposed that activated carbon also possesses almost all known organic functional groups lining up along the walls of the pores (Hassler, 1974). Some of these functional groups, such as carboxylic and phenolic, could dissociate to yield hydrogen ions in the presence of a solvent such as water. These ions could then act as charge carriers between the walls of the pores and, by doing so, would increase the conductance. The increase would continue as long as the sample is able to absorb more water until a maximum is reached when all the pores are completely filled.
A new technique for the preparation of activated carbon has been reported (Universiti Pertanian Malaysia, 1984). This new method may be used to produce fairly large pieces of activated carbon in contrast to the comparatively fine granules and powders prepared by current commercial processes. These large pieces are particularly valuable for determination of the physical properties of activated carbon. In this paper one such experiment is described. Activated carbon is structurally different from graphite because of the presence of pores of various sizes. In the simplest way, activated carbon can be viewed as a cluster of graphite microcrystals separated by these pores. The diameters of the pores in the activated carbon which range from 2 nm to 1000 nm (Ponec et ait 1974), are much larger than the interplaner spacing in graphite. Hence the pores act as barriers to the flow of electrons through the entire lattice of the microcrystals.
The rate at which the conductance increases would then depend upon the rate at which the water was sorbed. Equations expressing the
59
M. BADRI, KARKN A. CROUSF AND HARUN AWANG correspond to the measure of water, C penetrating into the sample through the pores normal to the hp surface. The change occurs because the cross-sectional area, A, of the water column in the sample also changes. The conductance is independent of the height since h remains constant. At any time t, the cross-sectional area could be given as
rate of flow of water into a capillary have been given as dh
dt
877
h
(1)
for a vertical capillary, and d£
3r
1
dt
4T/
£
A = 2pC +
fi(b-2
for small b, (2)
and dA * 2p dC
da - kh dA
(a - a Q ) = khA
(a - a o )da = (kh) 2 (p 2 ) ^1 dt
(10)
On integration, (10) would give (11) of
=2(kh)2(p2)lit
(3)
(11)
n
where o [s the conductance measured at time t^ OQ is the initial conductance and k is a proportionality constant. If the vertical flow of water in the capillary could be considered independent of the horizontal flow, differentiation of (3) would give
To eliminate kh, we use (9). Then 2p 2 3r The Vertical Flow
(4)
The flow of water into a vertical capillary is governed by equation (1). If the conductor is dipped in water such that the whole of its bp surface is at all times in contact with water, any change in conductance would be due to the rise of the water column through the vertical pores. Equation (4) then beomes
Equation (4) enables the contributions of the vertical and horizontal flow to the increase in the conductance of the sample to be considered separately. The Horizontal
(8)
and \at - 0o) = khA f (9) where 0 is the final conductance value when the whole cross-sectional area has been covered by water, A f . Substituting (5), (6), (7) and (8) into (2) would give
(a -
da = kh dA + kA dh
(7)
Integration of (7) would yield
Whereas, for an ordinary conductor, the conductivity is proportional to the ratio of the cross-sectional area to the length, for the sorption conductor under study, the conductance is proportional to the product of the height of water column, h, and the cross-sectional area, A; i.e. ) =khA
(6)
As h remains constant, equation (4) becomes
Pores in the activated carbon can be likened to capillaries extending in all directions. If the rate of flow of water into the pores could also be described by (1) and (2), we could then relate the change in conductance to the gradual filling of the pores by water.
(0-0
(5)
A = 2p£
for a horizontal capillary (Bikerman, 1970). In these two equations, h and C are the height and length of water column at time t; p , 5 and 17 are the density, surface tension and viscosity of water, respectively; g is the gravitational constant; r is the radius of the capillary and h is the final height of water.
Flow
da = kA dh
Consider a piece of activated carbon of rectangular shape having surface area (h x p) cm and thickenss b cm completely immersed in water If" the conductance is measured across its height, h, as in Fig. 1, any change observed would only
(13)
By integration, (13) becomes (14) and (15)
60
(a - a o ) - kAh
(14)
(af - a , = kAh f
(15)
CONDUCTANCE MEASUREMENT OF WATER-SORBED ACTIVATED CARBON
MATERIALS AND METHODS
A piece of activated carbon was prepared by heating a piece of coconut shell in vacuum as described elsewhere (Universiti Pertanian Malaysia, 1984). It was cut into a conductor of definite shape and dimensions as shown in Fig. 2a, The surfaces and edges were ground with sand paper and a fine grinding stone. The conductor was then boiled in distilled water for 2 days and in 0.1M HC1 for an additional 2 days, washed with distilled water in a Soxhlet appratus for 4 days and left to dry in air. The conductor was then attached with epoxy resin (Araldite) to a length of glass tubing at one end and a B7 ground glass cone at the other, Fig. 2b. When the glue had set, the whole assembly was dried at 110°C overnight, heated at 70°C for three hours in vacuum, and stored in a desiccator. Fig. 1
Horizontal flow of water through capillaries into a rectangular slab of activated carbon.
For the condutance measurements, the conductor assembly was joined to a J-tube through the ground joint, Fig. 2b. A few drops of mercury were then placed in each arm. Connections to an Autoblance Universal Bridge B642 were made through platinum wires. The conductor was placed in a dry test tube and equilibrated at the experimental temperature in a waterbath. The conductance of the dry conductor was measured before each experiment. When constant readings were obtained, some distilled water at that temperature was poured slowly into the test tube until the whole piece of carbon was submerged. After the initial conductance, 0o was noted, the conductance, a,was followed tnroughout the experiment until'the final conductance, Of, was obtained (after 4 days).
Dotted area shows the surface covered at any time t. This area, A, is given as A=2 (1 xp) + l(b
-21)
which is approximated as A ^ 21p. where h, is the final height of the column. Substituting (13) and (14) into (1) we would obtain 1
da
gr2p
o)
(16) kA dt
817
After each experiment, the conductor assembly was dried in vacuum and kept in a desiccator as described above.
and on integration
r-i—av (° /O
(tf-
~
CT
o) RESULTS
— a
When the activated carbon was immersed in water, its conductance increased with time until a constant value of af was reached as it became completely soaked. The results obtained at five different temperatures are given in Fig. 3. The inrease in conductance showed a short inductive period followed by an accelerated one before slowing down again as of was approached. The total time taken for the sample to reach its final conductance value became shorter as the temperature was raised.
(17)
kA 87?
Substituting kA from (15) and dividing through by (af - a Q ).(17) becomes (18) (18)
Thus measurement of the conductance of the sample completely immersed in water would seem to lead to the possibility of evaluating the average pore radius, r, since all the other constants are known.
Analyses of the results have been made using equations (12) and (18) for two different stages of each experiment. Plots obtained using equation 61
M. BADRI. KAREN A. CROUSE AND HARUN AWANG
(12) are given in Fig. 4. Except for slight deviation at 28°C, the results obtained seem to fit a straight line up to 70% of the total sorption fraction, ° ~~ °o . The slopes of these lines have
0.18
a
f- a o
been estimated and are given in Table 1 together with the values of r calculated using equation (12). 9
Plots obtained using equation (18) are also given for the various temperatures, Fig. 5. The data seem to fall on two straight lines intersecting at sorption fraction of about 70%. Since the lower fraction has been accounted for by equation (12)? the upper line has been associated with the flow of water into the vertical pores. The slopes of these lines at all five temperatures are given in Table 2 together with the calculated values of r using equation (18).
I
—>
—n
(a)
Carbon
DISCUSSION On a m'olecular scale, the external surface of the carbon piece would still be very rough with many large depressions and crevices despite the care taken during the grinding. The initial slow increase in the conductance during the inductive period could have been due to the gradual filling of these crevices with water. As the walls of these crevices came into contact with water, the functional groups either ionized or reacted with water to give hydrogen ions which could act as charge earners in the solution within the crevices. Since the ratios of the surface area of these crevices to their volume and to the total surface area including those of the pores are small, the number of functional groups involved in this step must be small also. Therefore, the initial increase in the conductance would be small.
B7 Joint
- Mercury
(b)
Fig. 2
Conductor
assembly
(a)
carbon conductor with dimensions given in cm. The length of each tip is 1 cm.
(b)
carbon conductor attached to glass and a J-tube through B 7 glass joint. The tips were covered with mercury for proper contact.
TABLE 1 Pore radius obtained using equation (12) Temperature
Slope
Surface Tension*
Viscosity*
°C
io V
dyne cm"
10"2g c m ' V 1
0 28 36 56 78
5.975 14.64 20.19 44.00 85.58
75.6 71.5 70.25 67.00 62.90
1.787 0.8327 0.7052 0.4961 0.3638
*CRC Handbook of Chemistry &; Physics, 1970 1971. 62
Radius pm 22.9 27.6 32.8 52.8 80.2
CONDUCTANCE MEASUREMENT OF WATER-SORBED ACTIVATED CARBON TABLE 2 Pore radius obtained using equation (18) Temperature °C 0 28 36 56 78
IO-V
Radius
g cm"
Viscosity* lO^gcm-V1
0.9998 0.9962 0.9937 0.9852 0.9730
1.787 0.8327 0.7052 0.4961 0.3638
643 646 652 822 957
Density*
Slope
3
1
0.9449 2.042 2.445 5.487 10.02
nm
*CRS Handbook of Chemistry 8c Physics, 1970-1971. The openings of the internal pores are probably sited in the walls of crevices. Once the crevices were filled, the water would start to flow into the pores. Since the proportion of the total surface area due to the pores is large, the number of functional groups involved must be large also. Their ionization would enhance the conductance of the sample tremendously. This is probably the factor responsible for the accelerated period noted in Fig. 3. When these pores were filled, the water would start flowing into the smaller, "closed-end" ones. The flow would be slower and perhaps complete filling might never be achieved beacuse of air trapped in these pores, thus restricting the conductance to a certain value. At higher temperatures, more of these "close-end" pores would be filled in a shorter time. The greater mobility of the ions and the increased dissociation constants of the functional groups at higher temperatures would result in a higher final conductance obtained in a shorter time. This is shown very clearly in Fig. 3.
8-
7-
I t
2-
Since the middle portion of the conductor was completely covered by water, the flow of water into the internal cavities could have taken place from any direction. Though a vertical flow through the lower bp surface would be fast, the area in contact with water was quite small because most of it was covered with glue. Thus, the horizontal flow from both sides of the ph and bp surfaces, (Fig. 1), is more important. The measurements of the conductor, (Fig. 2)t give p = 1 cm and Af = 0.18 cm2 Therefore, for the purpose of calculation of the radius of the pore through which the horizontal flow had taken place, equation (12) could be written as
1000 TIME
Fig. 3
2000 IN
MINUTES
The conductivity of activated carbon immersed in water at various temperatures indicated in °C.
Although about 70% of the sorption-fraction has been treated according to equation (12) in Fig. 4, it is also possible that the system can be treated using a combined mechanism including vertical flow. The assumptions already used still retain their validity since the two mechanisms are quite similar in the early part of the experiment when (o — o ) is very small, as evident
(19)
63
M. BADRI, KAREN A. CROUSE AND HARUN AWANG
100
200
300
400
500
o-sH
1-4J
0-2H
"SOIN 200
Fig. 4
600 TIME
IN
1000 MINUTES
f° ~ ° \\against time,
The plot of I
1500 MINUTES
2500
1400
Fig. 5
The plot of
°f " °o
" °o ,
In
t.
Of
- o
of-oo
against time, t. below. Equation (18) could be transformed to (20).
where x =
o-o
°and x would always be smaller
o. — o
-En °f of
— o
i
o. of
- o
8r?h,. o
(
t
f
(20)
f
a series (Forbes and Smyth, (1963). fin (1 - x) = - X - - L x 2 _ 1 3
Consider the logarithm term on the left. Cn
°f - °
Therefore (20) becomes
G
= £n
i-°o-O+Oo
= Cn (1 -
o
than one. The term could then be expanded into
— a
x)
64
~ a0
gr 2 p
• - a.
8T?hf
CONDUCTANCE MEASUREMENT OF WATER-SORBED ACTIVATED CARBON pores seem larger because less time would be required for completion of the process.
for small (a — OQ) the cubic term can be neglected and we would obtain (21)
The values of r given in Table 6 are much too small. Several factors may have contributed to this. The major factor could possibly be the assumption that equation (2) is applicable to carbon capillaries. Carbon is hydrophobic (Bikerman, 1970) whereas glass is not. Hydrophobicity would slow down the flow of water in the horizontal capillaries and make them seem smaller. To accomodate this, perhaps a correction is necessary in equation (12). This is left as a subject for future investigation.
(21) 8T?hf Equation (21) which relates the increase in conductiance to the vertical flow of water in the conductor is similar to (12). If the first part of the increase in the conductance was due to a combined mechanism, the slope would be the sum of the individual slopes in proportion;. t. e.
slope = c
gr2p
REFERENCES + d UNIVERSITI PERTANIAN MALAYSIA (1984): British
8i?h
Patent No. 2086864.
where (c + cl) = 1. Because r is small, the term containing r is small, implying that the mechanism is predominated by the contribution from the horizontal flow as suggested.
PONEC, V., K N O R , Z. and CERNY, S. (1974): Adsorp-
tion on Solids. London. Butterworths. pp. 577-578. BIKERMAN, J.J. (1970) : Physical Surfaces. London. Academic Press, pp. 35, 285.
Estimation of the radius of the pore using the slopes obtained is acceptable. The value of r calculated as shown in Table 7 falls within the mesopore classification (Ponec, 1974). The variation with temperature could have been due in part to thermal expansion of the conductor. However, a more likely explanation would be that the variation is due to the filling of the pores through condensation of vapour which would be expected to be more significant at higher temperatures. Such condensation would make the
HASSLER. J.W. (1974) : Purification with Activated Carbon. Industrial, Commercial, Environmental. New York, Chemical PubL Co. p 187. FOBES, M.P. and SMYTH, R.B. (1963) : Calculus and Analytical Geometry. N.J. Prentice-Hall, p 163. CRC Handbook of Chemistry and Physics (1970-1971) : Weast, R.C. (Ed.), Ohio. The Chemical Rubber Co. (Received 3 July, 1984)
65
Pertanika 7(3), 67 78 (1984)
A Simplified Method of Calculating Propeller Parameters for Small Trawlers. JUHARI HUSIN and ZAINAL ASHIRIN SHAHARDIN Department of Fishing Technology and Marine Science, Universiti Pertanian Malaysia, Mengabang Teltpot Kuala Trengganu, Terengganut Malaysia. Key words : Trawlers; simplified method of calculating propeller parameters. RINGKASAN Adalah menjadi masalah biasa dimana kipas yang dipasang di sesebuah bot tunda tidak dapat mengadakan tujahan yang mencukupi menyebabkan ia tidak dapat menunda dengan kelajuan yang ditetapkan. Tindakan-tindakan segera yang biasa diambil ialah mengecilkan saiz pukat, menukar kipas baru ataupun menggunakan kuasa enjin yang lebih tinggi. Semua pilihan yang dinyatakan akan mendatangkan kesusahan kepada nelayan daripada segt kewangan. Oleh itu satu kaedah mudah untuk mengira bagi mendapatkan satu spektra parameter-parameter kipas seperti garis pusat, nisbah pic-garis pusat, kelajuan pusingan, pekali kuasa kerejangan dan pekali prestasi kipas untuk sesebuah jenama enjin telah dicipta, bagi mengelakkan kejadian tidak cukup kuasa tujah. Satu kombinasi parameter-parameter yang paling baik boleh didapati untuk memastikan bahaiva kehendak-kehendak penundaan dipenuhi. Pada kebiasaannya kehendakkehendak dinyatakan dalam bentuk tujahan kipas untuk mengatasi jumlah serek pukat dikelajuan penundaan yang telah ditentukan. Jumlah serek sesebuah pukat boleh didapati melalui ujian model atau pun model matematik. Tiga buah jenama enjin telah dikaji dan untuk setiap jenama nilai-nilai rejangan, pekali prestasi kipas dan pekali kuasa-kerejangan dikira. Nilai nisbah pic-garis pusat diperolehi daripada kelok prestasi kipas apabila pekali tork (\l) dan pekali mara hadapan (
s o en
s
p
I C/3
TABLE 2 Calculated propeller thrust (T) at 2 knots trawling speed for the three engine power output, propeller speed and diameter.
Model X/ 3SMGGE, MCR45shp/2200rpm
Engine model
Model X/3KDGGGE, MCR-82shp/1450rpm
Model X/ 4KDGGGE, MCR-110shp/1450rpm
Maximum Torque (kgm)
44.6
59.4
74.3
89.1
103.9
123.1
164.3
205.4
246.2
287.6
165.2
220.4
275.6
330.3
385.8
Propeller speed (rpm)
733
550
440
367
314
483
363
290
242
207
483
363
290
242
207 GO
Thrust, T (kgO Propeller diameter (m) 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8
Thrust, T (kgf)
3
Thrust, T (kgf)
>
482 593 693
+ + +
+
+
+
535 656 747 +
+ 634 718 794
+ + + + + + +
+ + +
+ +
665 765 868 891
+
+
+ + + + +
+ + + + +
+
+ + 637 725 816 890 941 +
+ + +
+ + + +
+
+
+
+
+ +
+ +
862 1015 1178 1292 +
+ + + +
+ + + +
+
1090 12?8 1342 1454 +
+
+
1123 1256 1366 1499 1567
+ + +
+ + +
+ + +
+
+
+
+ + + + + +
+ + + + + +
1196 1302 1452 1547 1640 1682
+
+ +
+
+ + + +
+ +
1396 1547 1680 + +
• 1250 1390 1947 1615 1694 1754
+ + + + +
+
1246 1454 1599 1743 1832 +
+ +
+ + + + + +
+ + +
1351 1480 1660 1798 1930 2021
+ •
1472 1591 1740 1868 1979 2102
+ + +
+ +
+ + + + + + +
X iJU
>
1576
+ +
1641
2
1749 1939
^ i-
2076 2153 2236
'.-:*
r
+ = values out of range 3w
:-•
a
• 2
?
•
&?
:•»
5w o
r
••.
m
Model XI 4KDGGGE, MCR-110shp/1450rpm
Model XI 3KDGGGE, MCR-82shp/1450rpm
Model XI 3SMGGE, MCR-45shp/ 2200rpm
HO
33*0
• + • ! - ,- ^ , V f t *••
O t—i \j
Maximum Torque (kgm)
44.6
59.4
74.5
89.1
103.9
123.1
164.3
205.4
246.2
287.6
165.2
220.4
275.6
330.3
385.8
Propeller speed (rpm)
733
550
440
367
314
483
363
290
242
207
483
363
290
242
207
Pitch- diameter ratio (P/D)
+•
+
Propeller diameter
a
fm) 0.5 0.6 0.7 0.8 0.9 ]L.O ]L.I ]L.2 ]1.3 j1.4 ]L5
L . 1.6 1.7 1.8
Pitch- diameter ratio (P/D)
o *n n > n a > o
Pitch- diameter ratio (P/D)
t
•t-
5O O
1.25 0.82 0.53 + + + + + + + +
+
1.25 0.85 0.59 + + + + + + + 4-
+ +
+ +
+ +*
1.15 0.85 0.64 + + + + + + + + +
+ + +
1.15 0.88 0.63 0.50 + + + + + + +
+ + +
1.40 1.08 0.82 0.64 0.52
+
4
4
4-
1.38 1.02 0.74 0.57 +
4 4
1.14 0.90 0.70 0.54 + +
.
4
+
4
4
f
+ +
4
+ 1.25 1.00 0.81 0.64 0.53
4 4
1.28 1.07 0.86 0.71 0.58 0.50
+ + + + + + +
4
4
4
+
+
+
4
4
4
4
4
1.32 1.08 0.90 0.76 0.64 0.53
4
+
4
4
+
+
4
+ + + +
4 4
4-
4
+
4
4-
4
1.14
0.88 0.68 0.51
+ + +
+
+
4-
4
4
4-
+ +
4
(
+ 1-40
(
1.15
1.40 1.18 0.98 0.81 0.69 0.57
4
4
+
1.33 1.12 0-81 0.64 0.52
4
4
4
4
+
+
+
4
4
4
4
+
+
4
4
4
* 0.92 ' 0.72 0.61 0.52
m
r*
4
1 (
> 50 >
4
(-as
4
1.40 1.23 1.05 0.88 0.73 U.64 0.54
73
m H 70 m
— ?0
—> >
r H
values out of range.
50
TABLE 4 Calculated quasi- propulsive coefficient (T? D ) at 2 knots towing speed for variable engine power output, propeller speed and diameter. Model XI 3SMGGE, MCR45shp/ 2200rpm
Engine model Maximum torque (kgm)
(rpm
Model X/ 3KDGGGE, MCR/82shp/1450rpm
Model X/ 4 KDGGGE, MCR-110shp/1450rpm
44.6
59.4
74.3
89.1
103.9
123.1
164.3
205.4
246.2
287.6
165.2
220.4
275.6
330.3
385.8
733
550
440
367
314
483
363
290
242
207
483
363
290
242
207
X oo
2
* •
..
•
+
a N
Propeller diameter
(m) 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8
+
+ +
+
12.9 15.8 18.0
+
+
15.2 17.3 19.1
+
+
+
16.0 18.4 20.9 21.4
+
+
+
15.3 17,4 19.6 21.4 22.6
+ + +
+ + + + +
+
+
11.6 14.2 16.7
+ + + + + + +
+ = values out of range.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ +
+ +
+
+
+
12.1 13.7 15.2 16.5
16-5 18.3 19.8 21.3 22.4 23.2
+ + + + + +
+
+
+
+
+
+
+
+
+
+
+
+
+
+
11.4 13.4 15.5 17.1
+
+
+
+
+
+
+
+ -
+
+
+
+
15.8 17.2 19.2 20.4 21.6 22.2
+ + + +
+ + + + +
+ + +
14.4 16.1 17.7 19.2
+ + +
+ + + + +
+
+
14.8 16.6 18.0 19.8 20.7 + + +
+
-r
+
+
m
+
12.3 14.3 15.7 17.1 18.0 (;, + — +
+
13.3 14.6 16.3 17.7 19.0 19.9 + + +
14.5 15.7 17.1 18.4 19.5 20.7 + +
a
+
15.5 16.1
....
17.2
-•
19.1 20.4 21.2 22.0
c
> CO
TABLE 5 Calculated propeller performance coefficient (e) at 2 knots trawling speed for variable engine power output, propeller speed and diameter. Yanmar/ 3SMGGE, MCR^5shp/22OOrpm
Engine model
Yanmar/ 3KDGGGE, MCR-82shp/1450rpm
5 rr
o
Yunmar/ 4KDGGGE; MCR-11 Ushp/1450rpm
§
Maximum torque (kgra)
44.6
59.4
74.3
89.1
103.9
123.1
164.3
205.4
246.2
287.6
165.2
220.4
275.6
330.3
385.8
Propeller speed (rpm)
733
550
440
367
314
483
363
290
242
207
483
363
290
242
207
(e)
(e)
§ > 2 a
(e)
Propeller diameter (m) 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8
O
0.605 0.688 0.745 + + + + + + + + + +
+ 0.590 0.686 0.730 + + + + + + + + +
+
+ - values out of range
+ + 0.652 0.687 0.711 + + + + + + + +
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
0.613 0.672 0.731 0.691
0.567 0.634 0.705 0.728
+ +
+
+
+
+
0.633 0-678 0.712 0.732 +
0.571 0.648 0.680 0.709 0.705
+
+
+ + +
+ + +
+
+
+
0.574 0.620 0.666 0.690 0.688
+
0.627 0.667 0.701 0.725
+
+
+
+
+
+
+ •
+
0.590 0.635 0.660 0.700 0.695
+
+
+
+
+
+ +
+ +
+ +
+ +
+ +
+
+
+
+
+
+ +
+ ": + :
+
+
+
0.590 0.614 0.668 0.682 0.695 0.676
+
+
0.578 0.625 0.649 0.679 0.684 0.678
+
+
+
+
+ +
+ +
+
+
+
+
+
+
+
+
+
0.581 0.605 0.659 0.686 0.708 0.708 0.704
+
+
0.600 0.618 0.653 0.674 0.686 0.704
+
+
+
+
+
0.610 0.598 0.611 0.666 0.691 0.687 0.687
tn
r* trn
•i J
> >
S o r1 IT
J, HUSIN AND Z. A. SHAHARDIN
Principal Particulars Length overall • 13.0 m Loaded waterline • 12.0 m Moulded beam • 4.0 m Beam waterline • 3.9 m Depth moulded • 1.3 m Draughth ( a : • 0.82m Loaded block coefficient • 0 52 Loaded displacemen 1 21 tonnes.
a
tu
o
ao
a
f / /
-
/
<
£•0
/ /
20
RAWLING
SPEEO
_-*
KNOTS
*
^
I
CRUISING
Fig. 2. Curves of Total Gear Drag (kgf) and required effective horse power (ehp) versus trawling speed (knots) of a typical small trawl.
SPEEO • knots
Fig. 3. Relationship between required engine Brake Horse Power (bhp) and cruising speed (knots) of a hypothetical small trawler.
diet with the general belief that small trawlers are trawling at speed of 2.0 knots. This is not possible unless if they are using small trawls or having engines of larger capacity such as 3 KDGGGE — 82shp or 4 KDGGGE - 1 lOshp.
For a particular engine model, the actual propeller efficiency or quasi-propulsive coefficient (T?D) increases with the increase in propeller diameter and gear reduction ratio. This is in agreement with the generally accepted idea that propeller quasi-propulsive coefficient (VD) can be improved to a certain extent by increasing its diameter. The increase in quasi-propulsive coefficient (T?D) obtained by increasing propeller diameter for a gear reduction ratio is largely due to the increase in thrust. Similarly the rate of an increase in gear reduction ratio. However, for than the rate of increase of supplied power. Thus quasi-propulsive coefficient increases with increase in gear reduction ratio. However, for practical gear reduction ratio application, say 4 : 1 , the maximum quasi-propulsive coefficient for engines 3 SMGGE, 3 KDGGGE and 4 KDGGGE are 18%, 19.2% and 18% respectively.
For a particular engine model the pitchdiameter ratio decreases with increasing propeller diameter. For a pitch diameter ratio range of 3 : 1 , 4 : 1 , the gear reduction is 1.25 to 0.53 and 1.25 to 0.59 respectively. A similar trend is shown by engine model 3 KDGGGE and 4 KDGGQE whereby the pitch-diameter ratio drops with increasing propeller diameter for a particular gear reduction ratio. The variation is 0.83 for 3 : 1 and 0.60 for 4 : 1 in the case of a 3 KDGGGE model and 0.63 for 3 : 1 and 0.81 for 4 : 1 in the case of a 4 KDGGGE model. The reduction in pitch-diameter ratio is associated with increasing thrust. This is an interesting relationship since it is possible to control the thrust by controlling the pitch of a propeller. A comprehensive study on the possibility of fitting a controllable pitch propeller (epp) to a trawler for obtaining maximum efficiency and maximum thrust has been attempted by Kowalski et al. (1974).
Table 2 shows the trend of propeller performance coefficient (e) at a trawling speed of 2.0 knots for 3 engine models considered. The table shows that for a given engine model and gear reduction, the performance coefficient (e) increases with the increase in propeller dia76
A SIMPLIFIED METHOD OF CALCULATING PROPELLER PARAMETERS FOR SMALL TRAWLERS. meter. However, the maximum value of performance coefficient (e) is found to be decreasing with increasing gear ratio. These two trends are similar for all the engine models considered. The propeller performance curve at 4 : 1 gear reduction for 3 SMGGE, 3 KDGGGE and 4 KDGGGE are 73%, 72.5% and 70.5% respectively. Thus the values of propeller coefficient seems to depend to a large extent on propeller diameter and gear reduction ratio. Also from the comparison of 3 engine models, it is noticed that the coefficient seems to actually decrease with increasing engine output at a particular gear reduction ratio,
to be viewed cautiously since the total drag of gear used in the analysis is based on a single specification of a trawl used in the country. Therefore, trawling can still be done at 2.0 knots or more by using smaller scale gear. The conclusion that can be drawn here is that, small trawlers (engines less than 50 shp) having a trawl of the same specification as the one being tested will not be able to trawl at 2.0 knots. It is expected that there will be a slight variation in the calculated values of thrusts, pitch-diameter ratios, quasi-propulsive coefficient (TJD) and propeller performance (e) obtained when the basic characteristics of the propeller used in the analysis are changed. Such basic characteristics will include developed surface ratio (blade area ratio) and number of blades. However, the error introduced in the overall calculation will be about 5% (Rawson et al, 1967). Thus the method is suitable for use in preliminary design stages.
CONCLUSION The metnod used in assessment of propeller thrust is simple and can be used as tool in inspecting the range of thrust available for a particular engine model having a specified (MCR) power output, by varying propeller diameter and reduction gear ratio. The selection of gear ratio to a large extent depends on its size. A large reduction ratio requires a large gear box. The gear ratio of up to 4 : 1 is normally available in the market and is suitable for small engine application. The quasi-propulsive efficiency (17 ) increases with the increase in propeller diameter and gear reduction ratio. As stated earlier the increase in diameter and gear ratio is usually constrained by physical limitations such as the size of propeller and the size of gear box.
ACKNOWLEDGEMENTS The authors are grateful to Ir. Kamarudin bin Mansor, a naval architect of Limbongan Timor Sdn. Bhd. for his help and useful comments during the preparation of the manuscript. Thanks are also due to Haji Umar bin Salleh, the Head of Station, Universiti Pertanian Malaysia, Kuala Trengganu for his cooperation and encouragement. REFERENCES ANONa (1980) : Annual Fisheries Statistics 1980. Ministry of Agriculture Malaysia, Kuala Lumpur, 1981.
As for quasi-propulsive efficiency, the propeller performance (e) increases with the increase in propeller diameter for a given reduction gear range. However, the maximum values of (e) obtained at a particular gear reduction decreases with gear reduction ratio increment. The best propeller performance coefficient is obtained at gear reduction of 3 : 1 for all engine models being considered.
ANONb (1980) : Yanmar diesel engine instruction book 3, Yanmar Diesel Engine Co. Ltd. Tokyo, Japan. ANONC (1981) : Marine fuel management, Cummins Engine Co. Inc., Columbus, Indiana, USA. E L D E R E D . B. I N G L E ,
R.M. and W O O D B U R N , K.D.
(1968) : Biological observations on commercial shrimp, Peneaus duodrum: Burkenroad, in Florida waters, Fla., St. Bd., Conserv. Prof., Serial No. 3, p i -139.
The effective horse power required to overcome resistance of the boat hull of a typical small trawl at a trawling speed of 2.0 knots is found to be small. Thus at trawling, the assessment of effective horse power should only be based on the total gear drag of a small trawl. Total gear drag of a trawl under operation can be determined by conducting model experiments or mathematical modelling as has been suggested byKowalski et al (1974).
HusiN, J. and SHAMSUDIN, L. (1983) : Comparative analysis of the (20-40)hp inboard powered fishing boats used in West Malaysia. Pertanika 6(2), 55-62.
The results of thrust obtained indicate that most of the trawling operation carried out by small trawlers in West Malaysia is at a speed of less than 2.0 knots. However, this statement needs
KOWALSKI, T. and GlANNOTTl, J. (1974) : Calculation of trawling gear-trawlei interaction, University of Rhode Island, Marine Technical Report no. 17, Kingston, USA.
HASHIM, W. (1980) : Komuniti nelayan di Pulau Pangkor — Beberapa aspek ekonomi dan sosial. Dewan Bahasa dan Pustaka, Kuala Lumpur.
77
J. HUSIN AND Z. A. SHAHARDIN Techniques, Japan International Cooperation Agency, Tokyo, Japan, 1977, p 175-199.
KOWALSKI, T. and GiANNOTTl, J. (1974) : Calculation of trawling gear drag, University of Rhode Island, Marine Technical Report no. 16, Kingston, USA. KOWALSKI, T. and GiANNOTTl, J. (1974) : Calculation of fish net drag, University of Rhode Island, Marine Technical Report no. 15, Kingston, USA. MIYAMOTO,H. (1968) : Establishment of fishing gear research lab,. Report to the government of India, I AOTAno. 2599. p. 1-137.
SHAHARDIN. Z.A. (1983) : Model experiment on small shrimp trawls, M Sc. Thesis, Kagoshima University, Kagoshima, Japan. SHAHARDIN, Z.A., and HlGO, N. and HUSIN, J. (1983) : Feasibility studies on the double vs single rigged shrimp trawls using experimental models, International Conference on DMTLAR, Universiti Pertanian Malaysia, Aug 2-5th, 1983.
MATHEWS, S.T. (1966) : On economics of trawling, National Research Council of Canada, Report MB-265, Ottawa, Canada. NOMURA, M. and Y A M A Z A K I ,
RAWSON. K.J. and TUPPER, E.C. (1967) : Basic ship theory. Volume 2, Longman Group Ltd., London (4th impression, (1976), p. 390-392.
T. (1976) ; fishing
(Received 12 December, 1983)
78
Pertanika 7(3), 79-87 (1984)
Primary Productivity and Mineral Nutrient Status of some Estuarine and Coastal Waters along the East Coast of Peninsular Malaysia during the off Monsoon Period. LOKMAN SHAMSUDIN, M. ISA MANSOR and JUHARI HUSIN Department of Fisheries Technology and Marine Science, Faculty of Fisheries and Marine Science Universiti Pertanian Malaysia Mengabong Telipot Kuala Trengganu, Trengganu. Key words:
Mineral nutrients; primary productivity; estuaries; coastal waters. RINGKASAN
Satu penyelidikan tentang kedudukan organik dan bukan organik, produktiviti utama dan setengah setengah parameter alam sekitar bagi peraliran muaran dan tepian pantai di sepanjang kawasan tepian pantai Semenanjung Malaysia, menunjukkan bahawa muara memainkan peranan sebagai tempat punca pernbahagian nutrien ke kawasan tepian pantai yang berhampiran. Kandungan fotosintesis net bagi stesyenstesyen di muara adalah di antara 82.0-125.4 dan 104.0-257,9 \lg C/l/h manakala untuk stesyen-stesyen tepi pantai pula masing-masing di antara 42.0-164.5 dan 66.0-192.2 fJig C/l/h masa air pasang dan surut Semasa air surut di kedua-dua stesyen muara dan tepi pantai, nitrogen organik terlarut, partikulat fosforus organik dan nitrogen ammonia bukan organik adalah berkadar tinggi manakala oksigen terlarut, nitrogen nitrat bukan organik dan nitrogen nitrit adalah berkadar rendah sewaktu penyelidikan dilakukan. SUMMARY
A study of the organic and inorganic mineral status, primary productivity and related environmental parameters of some estuarine and coastal waters along the east coast of Peninsular Malaysia indicates that the estuarine waters act as nutrient sources for the adjacent coastal waters. The net photo synthetic values at the estuarine stations ranged from 82.0-125.4 and 104.0-257.9 jJig C/l/h while that of coastal stations ranged from 42.0-164.5 and 66.0-198.2 yg C/l/h during the high and low tides respectively. During the low tides, at both the estuarine and coastal stations, the dissolved organic nitrogen, particulate organic phosphorus and inorganic ammonium nitrogen were present in high concentrations while that of dissolved oxygen, inorganic nitrate nitrogen and nitrite nitrogen were low throughout the study period. community productivity and found it to be low. This could be due to various factors, viz. high turbidity of the water and its consequent low light penetration and high organic load leading to a high biological oxygen demand. Lee et al. (1980) carried out a study on the effect of oil palm effluents on nutrient status and planktonic primary production of a Malaysian mangrove inlet. They found that the polluted inlet had elevated nutrient levels but nevertheless primary production was higher in the unpolluted inlet. They also found that the toxic nature of the effluent overrode any eutrophication effect.
INTRODUCTION
There are few studies on nutrient contents or other related productivity parameters in tropical aquatic environments, especially estuarine or mangrove ecosystems along the coast of Peninsular Malaysia. Many of these water bodies have been reported to be polluted by agrobased effluents, untreated human and animal wastes, and siltation due to erosion from land development (Bishop 1973, Law etal, 1980;Shamsudine* al., 1982). Unfortunately many of these investigations were not related to the organic content of the system. Ong et al. (1980) working on tropical mangrove ecosystems, calculated the net aquatic
The present investigation is a study of the nutrient status, both organic and inorganic, and 79
LOKMAN SHAMSUDIN, M. ISA MANSOR AND JUHARI HUSIN
With the help of a Kemmerer water sampler (capacity 1.751), 5-7 subsurface samples (at depth .5m) at each of the sampling stations were taken to the laboratory for analysis immediately, ie, analysis was done 2 to 3 hours' after sampling. Altogether, at least 10 duplicated samples were carried out for each of the various determinations at any one given time and the volume of the sample used is in accordance with their respective mentioned methods. Pretreatment filteration of the sample was carried out to separate paniculate matter in water for analysis or to obtain a particle free sample of water for the analysis of soluble material. Whatman GF/C (Glass Filter) grade filter papers (47mm diam discs with a pore size of 2-3 fi) were employed and the filteration was done at a suction pressure of less than 15 p.s.i. Photosynthetic measurements were carrried out according to the modified method of Bryan et al.y (1976) This gives a Winkler titration coefficent variation of 0.1%.
the related productivity parameters of various estuarine and coastal waters along the east coast of Peninsular Malaysia, especially the coast of Kelantan and Trengganu. METHODS AND MATERIALS
Six estuarine stations (namely, Dl, PI, Cl, Kl, Tl and TP1) and six coastal stations (namely, D2, P2, C2, K2, T2 and TP2) were selected along the coast of Kelantan and Trengganu and the research was carried out between April to May 1983 (the off-monsoon period) during two mean tidal ranges, viz. a mean low tidal range of 0.7 ± 0.5 m and a mean high tidal range of 1.2 0.5 m referring to a tide table). The estuarine station is situated in the middle of the given river estuary itself while the coastal station is situated approximately 100 m offshore adjacent to the given estuarine river mouth. The areas under study include those estuaries of sungei Dungun, Sungei Paka, Sungai Cukai, Sungai Kerteh, Sungai Golak or Taba and Sungai Tumpat as shown in Figures 1 (Station names derived from their respective first alphabetical letter).
A modification of Solarzano's method (1969) by Shamsudin (1979) was used to determine ammonium in order to eliminate the high blank values, which is basically a colorimetric phenolhypochlorite method. In this modified method, one of the reagents, phenol in methanol, is used in preference to phenol in ethanol as it will give a lower value for the blank (Shamsudin, 1979). Flasks used during the analysis were covered with aluminium foil to minimise light interference. The water solvent used for reagent preparations, blanks and glassware washing is first distilled followed by a deionisation process by passing through a cation exchange resin to remove the last traces of ammonium ions. This method requires careful attention to light interference as well as contamination and has a precision of ± 10% on a routine basis. Nitrate nitrogen was determined by the colorimetric cadmium copper amalgam reduction method (Strickland and Parsons, 1972); the reactive phosphorus was carried out by the colorimetric ascorbic molybdate method (Strickland & Parsons, 1972). Salinity and temperature at the sampling stations were measured in situ with a portable battery-operated SCT meter (YSI model 3). The pH was measured in situ using a portable battery operated pH meter (Schott Gerate pH meter Cg 817) which provides accurate digital reading over its 0-14 range with a resolution of 0.1 pH units, reproducible to ± 0.05 pH. Determination of total dissolved phosphorus and particulate phosphorus in natural waters was carried out according to the method of Solorzano and Sharp (1980b), which gives 100% recovery with refractory phosphorus compounds
Fig. 1, Map showing sampling stations along the coast of Kelantan and Trengganu. 80
PRIMARY PRODUCTIVITY AND MINERAL NUTRIENT STATUS OF SOME ESTUARINE AND COASTAL WATERS coastal stations ranged from 0.84 - 3.20 and 0.96 — 3.60 fig at N/l at coastal stations during the high and low tides respectively. The particulate organic phosphorus ranged from 0.12 — 0.72 and 0.43 — 1 02 jLtg at P/l at estuarine stations during the high and low tides respectively while the values ranged from 0.22 - 0.67 and 0.25 - 0.35 — L95 jug at P/l at coastal stations during the high and low tides respectively. Generally, the dissolved organic phosphorus contents at both the estuarine and coastal stations were found to be significantly lower as compared to that of particulate organic phosphorus and dissolved organic nitrogen throughout the study period.
and has a precision of ± 10%. This method involves drying a sample with magnesium sulphate and baking the residue at a high temperature to decompose organic phosphorus compounds. The residue is then treated with hydrochloric acid to hydrolyse poly phosphates and the orthophosphates and this is followed by the molybdate method. Total dissolved nitrogen in natural waters was determined according to the method of Solorzano and Sharp (1980a), which has a maximum capability of 40 HM nitrogen in undiluted samples and a precision of ± 2%. This method requires careful attention to pH, alkalinity, the neutralising buffer, reaction vessels and dilution factors.
The net photosynethetic values at the estuarine stations ranged from 82.0—125.4 and 104— 257.9 Mg C/l/h during the high and low tides respectively while the values at the coastal stations ranged from 42.0 - 164.5 and 66.0 - 198.2 jug C/l/h during the high and low tides respectively. High net photosynthetic values were observed at all stations during the low tide throughout the study period. Station TP1 had the highest primary productivity, nitrate nitrogen and ammonium nitrogen values especially during low tides throughout the study period.
RESULTS High ammonium nitrogen concentrations were generally present at all estuarine stations, namely, stations Dl, PI, Cl, Kl, Tl and TP1 especially during the low tides throughout the study period. These ranged from 0.28-4.4/ig at NH*-N/1 and 0.22-3.10 jug at NH^-N/1 during the low and high tides respectively at the estuarine stations (Tables 1 — 2). Similar tendencies for ammonium nitrogen concentrations were also observed at coastal stations, namely station D2, P2, C2, K2, T2 and TP2, during both the high and low tides. These ranged from 0.11 -2.80 Mg at NH*-N/1 and from 0.44 - 3.30 Mg at ' NH^-N/1 during the high and low tides respectively at the coast stations (Table 3 — 4). However, the ammo nium nitrogen values for the coastal stations were relatively lower than their respective estuarine stations throughout the study period. The nitrate nitrogen contents at the estuarine stations ranged from 0.32 - 1.80 and 0.16 - 1.30 Mg at NO~—N/l during the high and low tides respectively. At the coastal stations the values ranged from 0.29-1.60 and 0.20-1.48 Mg at NO «N/1 during the high and low tides respectively. The reactive phosphorus and nitrite nitrogen contents at the estuarine and coastal stations did not show any definite trend and their contents were less than 0.02 and 0.08 Mg at N/l respectively.
The temperature values were relatively constant at all stations throughout the study period (Tables 1 — 4). At all stations, the'pH and the salinity values were low during the low tides and vice versa during high tide. The salinity ranged between 19 - 29 and 18 - 24 p.p.t. at estuarine stations during the high and low tides respectively while the salinity was constant (32 p-p.t) at coastal stations throughout the study period. The dissolved oxygen contents at estuarine station ranged from 5.10 - 5.87 and 4.95 - 5.71 mg O J 1 during the high and low tides respectively. At the coastal stations, the values ranged from 5.90 — 6.68 and 5.18 — 6-06 mg O_/l during the high and low tides respectively. DISCUSSION AND CONCLUSION The investigation which was carried out at various estuarine and coastal waters along the east coast of Peninsular Malaysia indicated that the estuarine waters were more productive then the coastal waters especially during the low tides. It was also observed that the net photosynthetic values and the nutrient contents, especially ammonium nitrogen and dissolved organic nitrogen, were significantly higher during low tide than high tide at both estuarine and coastal waters. During the low tides, dissolved oxygen and nitrate nitrogen contents were observed to have dropped considerably while inorganic and organic ammonium rose at all stations. This was
Relatively high disolved organic nitrogen contents were observed at both the estuarine and coastal stations during the low tides and vice versa during the high tides, indicating similarity to those of ammonium nitrogen contents. These ranged from 3.81 - 10.20 and 9.26 - 11.23 Mg at N/l at estuarine stations during the high and low tides respectively while the values at the 81
TABLE 1 Productivity of various estuaries along the east coast of Peninsular Malaysia during the off — monsoon period at high tide in April May 1983. (Sampling depth 0.5 m, Time 0830 0930 h, Tide 1.2 ± 0.5 m). VR 83
ST
T
pH
D\
30
5 DOPMgat/1
VOPMgat P/1
XK'I PS/xgC/1/h
>
ND
,12 + .04
104.1 + 16.3
j£
.67 + .08
92.3 + 13-9
.11 + .02
.72 + .09
88.0 t 15.8
5.60 + .56 9.12 ± .92
ND
.45
i .05
125.4 t 25.9
MI>gat/l
NO;lugat/l
\
±.5
29.4
Kl
30 +.5
8.33 +.35
19 +.5
2.56 1 .21
.45 + .06
.04
l >3
Tl
30 + .5
8.24 29 +.30 + .5
.98 + .08
.74 + .08
.04. + .006
.01 + .004
5.40 + .5 6 7.61 + .45
.01 + .004
.39
+ .04
18.5
TP1
30 £.5
8.16 27 +.08 + .5
3.10 + .39
1.80 + .19
.02 + .004
ND
5.10 ± .52 3.81
.01 ± .002
.69
+ .09
+ .17
82.0 t
I
18 3
-
114.5 + 14.2
G > >
2 r Note: N'D-Not detectable, DON-Dissolved organic nitrogen, DOP-Dissolvcd organic phasphorus, POP-Particulate organic phosphorus, ST-Station, T-Tcmpcrature C, + denotes Standard deviation
O D
Q TABLE 2 Productivity of various estuaries along the east coast of Peninsular Malaysia during the off monsoon period at low tide in April {Sampling depth 0.5m, Time 1430 - 1530 h. Tide 0.7+ 0.5 m) YR1 84 DATE
ST
T
pH
25.4
Dl
30
26.4
PI
27.4
Cl
17.5 18.5
Tl
.TP
5.56 ± .58 9.26 ± .48
.06 + .002
.43 + .04
192.0 t 25.3
.01 + .003
4.95 + .83 9.54 ± .58
.17 ± .02
1.02 + 0.23
118.3 + 11.3
.07 ± .009
.02 + .004
5.71 + .43 10.29 + .93
.01 + .002
.44 + .04
125.0 + 12.9
.16 + .02
.06 + .008
.01 + .004
5.50 + .38 10.94 + 1.2
.05 + .008
.61 ± .88
224.4 + 22.5
1.20 ± -15
.42 ± .06
.03 ± .004
.01 + .002
5.20 + .29 11.23 +. 1.8
.02 ± .006
.60 + .07
104.0 + 15.3
4.40 ± .49
1.30 ± .16
.02 + .003
.01 + .002
5.00 + .73 10.67 ± 1.3
.01 + .002
.98 ± .08
257.9 ± 30.3
PO4Mgat/l
O2mg/1
7.85 24 ±.15 ±.5
2.92 ± .36
.15 ± .03
.02 ± .004
.01 + .002
7.85 22 +.05 ±.5
1.47 + .18
.48 + .08
.01 ± .005
7.96 24 +.08 ±.5
.28 ± .04
.35 ± .05
7.90 18 ±.16 ±.5
2.67 + .28
±.5 30 ±.5
7.86 22 ±.18 ±.5
30
7.75 22 ±.24 +.5
30 30 +.5
Kl
NETPSjUgc/1/h
NO 2 flgat/l
+.5
29.4
POPjUgat/1
NO 3 /igat/1
+.5
30
+.5
>
May 1983.
DOP/igat/1
NH+jt/gat/l
S%
<
DONjUgat/1
u E 2 C
S H
en
o
w
pi
Note XD-Not detectable, DON-Dissolved organic nitrogen, DOP-Dissolved organic phosphorus, POP-Particulate organic phosphorus, ST-Stations, T-Temperature C, + denotes Standard deviation
c
25 -
>
r >
H W
5
TABLE 3 Productivity of Coastal waters around the vicinity of their respective river mouths along the east coast of Peninsular Malaysia during the off-monsoon period at high tide in May — April 1983. (Sampling depth 0.5 m, Time 0830-0930 h. Tide 1.2 + 0.5 m). YR 83 DATE
ST
T
pH
S%
N » ; Ugat/1
NO 3 Mgat/l
NO 2 Mgat/l
PO 4 ^ g a t / l
°2 mg/1
30 8.1 32 1.70 + .25 .29 ± .03 .03 f_ .004 5.90 ± .02 ± .004 ±.5 ±.8 +.5 26.4 P2 30 8.3 32 .02 .02 + .005 6.58 + .42 + -05 .006 1.31 t.21 +.5 +.4 + .5 27.4 C2 .91 ± .08 30 8.2 32 .02 ± .008 6.21 + .11 + .03 .05 + .006 +.5 +.5 t.5 29.4 K2 6.04 t 30 1 9 1 + .24 8.3 32 .94 + .07 .05 + .007 .02 + .008 ±•5 ±.4 +.5 17.5 T2 30 8.2 32 1.11 + .18 .53 + .86 .05 + .008 6.05 ± .02 ± .006 +.5 +.3 +.5 18.5 TP2 30 8.1 32 2.80 ± .30 6.30 ± 1.60 + .18 .02 + .004 ND +.5 + .5 + .5 Note: ND-Not detectable, DON-Dissolved organic nitrogen, DOP-DissoIved organic phosphorus, POP-Particulate organic phosphorus, ST-Stations, T-Temperature°C, + denotes Standard deviation 25.4
D2
DON)Ugat/l
5* CO
>
DOPjUgat/1 POP/Ugat/1
N E T PSjuc/1/h
a
.22 ± .04 68.0 ± 7.2
.58
.84 3t .05
ND
.74
1.59 + .18
.03 + ,006 .28 + .06 81.3 + 8.9
-83
2.67 ± .22
• 11 t .012 .67 + .08
.95
2.25 + .24
.03 + 0 0 4
.44 + .06 151.2 + 20.4
.78
.96 ± .08
.02 + 005
.50 + .08
.74
3,20 + .35
.01 + .008 .50 f .06
62.0 t 7.4
'Z
o 73
42.0 + 5.8 164.5 + 20.7
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THE EFFECT OF PROTEIN (AS FISH MEAL) ON RUMEN VFA PATTERNS OF MOLASSES-FED SHEEP
TABLE 3 The mean (± S.E.) molar proportions of acetic (C 2 ), propionic (C 3 ) and butyric (C 4 ) acids of samples, the man (± S.E.) molasses intake and the relationship between molar percentages and the molasses intake for Sheep 1', 2 and 3.
Sheep
1.
Period
No. of observati ons
Acid
+ fish meal
10
C
2
10
C
3
10 fish meal
14 14 14
+ fish meal
2.
- fish meal
21
fish meal
3.
+ fish meal
c4 c2 c3 c4 C
21
C
21
C
2 3 4
±
1.3
19.7
±
0.7
34.6
±
1.1
41.7
±
0.8
24.9
1444
13 7a
NS Positive correlation (r2 - 0.47, P < 0.05) NS
1182
±
52
b
Negative correlation (r 2 = 0.35, P Bacillariophyceae > Cyanophyta > Euglenophyta > Chrysophyceae > Pyrrhophyta; and in decreasing numerical abundance : Cyanophyta > Chrysophyceae > Chlorophyta > Bacillariophyceae > Euglenophyta > Pyrrhophyta. High phytoplankton densities more or less coincide with the high values of primary productivity indicating some correlation between the two factors.
From the results, it seems that the brown water system supports a higher phytoplankton population and has higher phytoplankton productivity than the white water system. This could be due to the high concentration of suspended solids in the white water system. Although both the white and brown water systems consist of the same species of phytoplankton, their patterns of fluctuation and abundance are different. Chlorophyta and Bacillariophyceae of the white water system are very small in densities and contribute little to the total fluctuation of phytoplankton population in this system. Cynophyta and Chrysophyceae however, exhibited a peak in' July — August (Fig. 2). Similar to the blue green population of the white water system, the blue greens of the brown water system shows high densities during June — August period. Chlorophyta and Chrysophyceae, however, exhibit bimodaf fluctuations with small peaks in April and July; February and July respectively (Fig. 3). In Paya Bungor, the data shows that when the phytoplankton density is high, the nutrients such as phosphates and nitrates are low, indicating rapid utilization of these compounds by the algae growth (Figs. 8 and 9). However, it is observed that the nutrient concentrations are high just before and after the phytoplankton peaks. This is in agreement with the findings of Rzoska and
105
M.Y. FATIMAH, A.K. MOHAMMAD MOHSIN AND A.S. MUSTAFA KAMAL
Cyanophyta Chtorophyta
1283
BacillarophyciJ* Chrysophyc«a,
8
1982
Fig. 2. The fluctuations of phytoplankton density (cells/ml) in the white water system of Paya Bungor from October 1981 to September 1982. in April) and low densities in the wet season (October to December). The declining rate of primary production and population densities during the wet season could be attributed to the dilution of planktonic organisms following the increase in the volume of water. Some of the plankton could also be flushed off from the lake into the effluent river during high water levels The seasonal decline in solar radiation and hence the intensity of light during the wet season is likely to be a major factor in depressing primary production at this time.
Tailing (1966) that the nitrate content is very low during the maximum growth of diatoms. Prowse and Tailing (1958) also reported occurrence of nitrate accumulation at the beginning and end of phytoplankton growth. In Plover Cove Reservoir, Hong Kong, Hodgkiss (1974) found a decrease in phospate as a result of the increased growth of blue green algae. Generally, the phytoplankton population assumes higher densities during the dry season (January to September with scattered rainfall 106
PHYTOPLANKTON COMPOSITION AND PRODUCTIVITY OF A SHALLOW TROPICAL LAKE
-
Cyanophyta Chlorophyta
• — •
BacillanophjrciM ChrysopHyeiat
Fig. 3. The fluctuations of phytoplankton density (cells/ml) in the brown water system of Pay a Bungor from October 1981 to September 1982.
TABLE 3 Mean gross primary productivity (GPP) and net primary productivity (NPP) in mg C/l/day at 2 stations in Paya Bung^r, Pahang.
Mean
Minimum
GPP
0.334
0.083 (December)
0.761 (July)
NPP
0.204
0.43 (December)
0.587 (July)
GPP
0.479
0.179 (November)
1.310 (February)
NPP
0.294
0.152 (November)
0.713 (February)
Station Station II (White Water
Station IV (Brown water)
Productivity (mg C/l/day) Maximum
107
M.Y. FATIMAH, A.IC. MOHAMMAD MOHSIN AND A.S. MUSTAFA KAMAL
T
T
r
L •5
1
•> 0-8
T
0-7-
0-6-•
0-5-
0-4- •
0-3-
0
0-2- -
E 0-1- -
JAN
F€B
fVWY
APR
Wff
JUN
JUL
AUG
SEP
OCT
MOV
DEC
1982
Fig. 4. The seasonal variations of gross primary productivity (GPP) and net primary productivity (NPP) in Secchi disk transparency in the white water system during 1982. 108
PHYTOPLANKTON COMPOSITION AND PRODUCTIVITY OF A SHALLOW TROPICAX LAKE
GPP NPP
1.5
1*3
'day
1.2
M
-
VO
t
0-9 0*8 0-7
Primary
1
0*6 0*5 0*4 0-3 0-2 0-1
0 JAN
FEB
NtftR
APR
MAY
JUN
JUL
AUG
SEP
OCT
N0V
DEC
1982
Fig. 5. The seasonal variations of gross primary productivity (GPP) and net primary productivity (NPP) in mg C/l/day with Secchi disk transparency in the brown water systems during 1983. 109
M.Y. FATIMAH, A.K. MOHAMMAD MOHSIN AND A.S. MUSTAFA KAMAL
04
qg
0*
1Q
1.2
1-4
1-6
)&
20
01
0,^2
03
QL2
0-3
04
05
0^
0-?
Qj
02
03
0-5
OS
0-1
Q2
0-3
04
Q;6
01
OCT
SEPT
JULY
0-1
04
03 Q-3
04
I
04
.GPP .NPP
Fig. 6. The depth profiles of gross primary* production (GPP) and net primary production (NPP) in mg/C/1/ day in the white water system, Paya Bungor, during 1982. High turbidity values and hence low transparency values caused by the land run-off during the wet season reduces the amount of light intensity in the water. This is enhanced by the shallow nature of the lake and its susceptibility to wind actions. The decline of primary production in the wet season may be caused by the dilution of essential ions. This is probably because the run-off water has low nutrient content. Odum (1971) reported that the soils in the catchment area in the tropics, although rich in aluminium and iron, are, however poor in biologically essential elements such as phosphorus and nitrogen. The dilution of lake waters by run-off from ion deficient,uproductive catchment areas has been reported elsewhere in the tropics (Tailing and Tailing 1965, Imevbore 1967, Sreenivasan 1970).
Lim (1982) reported mean values lor gross primary production and net primary production in Taman Jaya lake to be 5.16 mg C/l/day and 2.88 mg C/l/day respectively. However, primary production values of Paya Bungor are higher than that found in other swamp lakes such as Tasik Bera. Okino and Lim (in Furtado and Mori, 1982) reported gross primary productivity of Tasik Bera to be from 0.07 - 0.25 mg C/l/day. Productivity depth profiles indicate that maximum production generally occurs at the top layer of the water. From June to October, however, maximum production occurs at the subsurface layers which may be due to the surface photoinhibition caused by high solar radiation on hot days. In July, when the transparency was deepest, maximum production occurred at the bottom layer (Fig. 6). In general, the depth at which maximum rate of plankton production occurs varies with the transparency of the water, which is in turn governed by the concentration of dissolved and particulate matter and abiotic turbidity (Wetzel, 1975).
The values for gross primary production in Paya Bungor are low compared to the values of eutrophic lakes in this region. Saravanamuthu and 110
PHYTOPLANKTON COMPOSITION AND PRODUCTIVITY OF A SHALLOW TROPICAL LAKE
iC/l/day 02
04
0-6
08
10
12
M
16
18
02
04
0-6
OS 1,0
02
1;2
04
0<
08
04
&6
08
02
0,6 0^
0-4
JULY
JUNE I
01
02
03
04
01
\
\ALX3
q2
06
g.4
APR
MAR
02
to
02
0,3
04
0-5
01
OS 10
MAY
02
03
04
OCT
2
t 01
02
'/ 03
04
0 1 0 2
O;3
/ /
1if
1
/ /
04
05
/\
_ _ GPP _.... NPP
\ DEC
/
. 7. 7^1^ depth profiles of gross primary production (GPP) and net primary production (NPP) in mg C/1 / day in the brown water system, Paya Bungor during 1982.
JUN
Fig. 8.
JUL
AuG
Sir
Annual Variations of PO (fJgl'1) at Different Stations in Paya Bungor, Pahang, During 1981 1982. Ill
M.Y. FATIMAH, A.K. MOHAMMAD MOHSIN AND A.S. MUSTAFA KAMAL
1;
Fig. 9,
Annual Variations of Nitrate-Nitrogen (mg T ) at Different Stations in Paya Bungor Pahangy During 1981 - 1982.
Therefore, the seasonal variations of phytoplankton growth and productivity in Paya Bungor is greatly influenced by the changes in the physicochemical properties of the water which themselves are determined mainly by the climatic changes of the region.
FATIMAH,
M.Y., AMBAK, M.A. and MOHSIN, A.K.M.
(1982) : Diurnal fluctuations of some physicochemical parameters of a swamplake in Malaysia. Malays. Appl. Biol 11(2) : 72-83. FATIMAH, M.Y.; KAMAL,
ACKNOWLEDGEMENTS This research was supported by Universiti Pertanian Malaysia research grant' 1713 — 1 — 316. The authors would like to extend their thanks to Perumal Kuppan, Jasni Md. Yusoff and Rarhlan Meon for their technical assistance in the field and in the laboratory. Thanks are also due to Mohd. Azmi Ambak for reading the manuscript and Jamilah Abdol for typing it.
M. and MOHSIN, A.K.M. :
(1983) : Some aspects of limnological features of a swamp lake with observations on its suitability for fish culture. Research Project Report No. 1713316 submitted to the Faculty of Fisheries and Marine Science, 1412 pp. FURTADO. J.I, and MORI,S. (eds.) 1982) : Tasik Bera, the ecology of a freshwater swamp. The Haque Boston - London. Dr. W. Junk Publishers. 413 pp.
REFERENCES
HODGKISS, U . (1974) : Studies on Plover Cove Reservoir, Hong Kong: Composition and distribution of phytoplankton and its relationship to environment tal factors. Freshwat. Biol 4 : 111-126.
AMERICAN PUBLIC HEALTH ASSOCIATION (1976) : Standard Methods for the examination of Water, Sewage, and Wastewater. New York. APHA. 14th edition, 1193 pp.
HUTCHINSON, G.E., (1967) : A Treatise on Limnology II. Introduction to Lake Biology and Limnoplankton. New York, John Wiley & Sons, Inc., 1115 PP.*
112
PHYTOPLANKTON COMPOSITION AND PRODUCTIVITY OF A SHALLOW TROPICAL LAKE production, and fish production on a tropical pond. Limnol Oceanogr., 9(4) : 391-396.
IMEVBORE, A.M.A. (1967) : Hydrology and plankton of Eleiyele Reservoir, Ibadan, Nigeria Hydrobiotogia, 3 0 : 154-176.
SREENIVASAN, A. (1968) : The Limnology and Fish production in Two ponds in Chinglepat (Madras). Hydrobiologia, 32:131-144.
MELACK, I.M. (1979) : Photosynthetic rates in four tropical fresh waters. Freshwaters Biology. 9 : 555-571.
SREENIVASAN, A. (1970) : Limnology of tropical impoundments : A comparative study of the major reservoirs in Madras State (INDIA) Hydrobiologia, 36 : 443-469.
ODUM, E.P. (1971) : Fundamentals of Ecology W.B. Saunders Co., Philadelphia. 574 pp. PROWSE, G.A, & TALLING, F.J., (1958) : The seasonal growth and succession of plankton algae in the white Nile, Limnol Oceanogr. 3 : 222-237.
TALLING, J.F. and TALLING, J.B. (1965) : The chemical composition of African lake waters. Int. Revue, ges, Hydrobiol $0 : 1-32.
RZOSKA, J.P. & TALLING, F.S. (1966) : The development of plankton in relation to hydrological regime in the Blue Nile. J. Anim. Ecol 55 : 637-662.
VOLLENWEIDER, R.A. (1974) : A manual on methods for measing primary production in Aquatic Environment, IBP Handbook no. 12. 2nd edition. London. Blackwell Scientific Publ. 225 pp.
SARAVANAMUTHU, J., and R. P. LIM (1982) : A preliminary Limnological survey of an eutrophic pond, Taman Jaya Pond, Petaling Jaya. Malay. Nat. J. 35 : 83-97.
WETZEL, R.G. (1975) : Limnology. Philadelphia. W.B. Saunders, Co. 743 pp. (Received 13 June, 1984}
SREENIVASAN, A. (1964) ; The limnology, primary
113
Pertanika 7(3), 115
119 (1984)
•
Some Quality Parameters of Intermediate Moisture, Deep-Fried Mackerel (Scomberomorus commersoni, Lacepede) YAAKOB CHE MAN and MAZXAH ATAN1 Department of Food Technology, Faculty of Food Science and Technology, Universiti Pertanian Malaysia, Serdang, Selangor, Malaysia. Key words:
Water activity (a w ^. Intermediate Moisture foods; humectant. RINGKASAN
Ikan Tenggiri Lembapan Sederhana dirempahi dengan ramuan tempatan telah disediakan dengan kaedah rendaman daripada larutan akuas mengandungi PEG 200, asid sorbik dan BHA. Hasil ini digoreng pada suhu 190°C selama 3 dan 5 minit, menyebabkan aktiviti air (&-J masing-masingnya 0.84 dan 0.80. Sifat-sifat kimia, fizikal dan deria telah dtuji. Ikan Tenggiri Goreng Lembapan Sederhana umumnya di dapati boleh diterima. SUMMARY Intermediate Moisture Deep-fried Mackerel seasoned with local ingredients was prepared by infusion method from an aqueous solution containing PEG 200, sorbic acid and BHA. The products were deep-fried at 190°C for 3 and 4 minutes, resulting in water activity (a^J of 0.84 and 0.80 respectively. Tests on chemical; physical and organoleptic properties were carried out The Intermediate Moisutre Deepfried Mackerel was found to be generally acceptable. baum and Karel, 1970). Humectants have been incorporated to lower a and thus control bacterial growth. Molds are more effectively inhibited by antimycotics. Antioxidants and better packaging materials have been widely recommended to overcome oxidative rancidity problems.
INTRODUCTION Deep-fried Mackerel (Scomberomorus commersonu Lacepede) is a familiar delicacy to all Malaysians. However, it has never been thought of as an example of an Intermediate Moisture Food (IMF). Research on the acceptability and stability of intermediate moisture fish is very limited except for a preliminary study by Collins and Yu (1975) where catfish was deep-fried to achieve a suitable a range and a more recent work by Dymsza and Silverman (1979).
The objective of this study was to develop an Intermediate Moisture Deep-fried Mackerel by combining deep-frying and the use of selected solutes. This paper presents the chemical, physical and sensory characteristics of the product.
In tradtional IMF for human consumption, the chemical activity of water is depressed either by salt or sugar. Recently, however, other humectants such as sorbitol and glycerol have been used to formulate IMF either by blending or infusion. More research is being done on the latter since IMF has been known to be susceptible to various degradative changes such as lipid oxidation, browning and microbial growth (Labuza, Tannen-
MATERIALS AND METHODS Product Preparation The ingredients used are shown in Table 1. A description of the method of preparation is outlined in Fig. 1. The control and infused samples were deep-fried in corn oil at 190°C for 3 and 5 minutes.
1
Present address: Food Technology Division, MARDI, Serdang, Selangor.
Key to author's name: Y. Che Man, M. Atan. 115
Y. CHE MAN, M. ATAN. TABLE 1 Ingredients used in the development of Intermediate Moisture, deep-fried Mackerel for 300 g flesh
FISH FLESH
I ( I I INTO SMALL P1F.CKS (4.0cm x 0.75cm x 3.0cm!
I WASHED (USING SALT UfDWATBft)
J IMMERSED IN INFUSION MIXTURE FOR 2 0 MINUTES
L E F T T O S T A X D FOR 20 - 3 0 MINUTES I
EXCESS SOLUTION DRAINED O F !
D E E P ! Rll D A ! t9tf*C K)K
MIXED mROl'Cm.Y WITH SI ASON1NG MIXTURI
0OOLED
LEFT TO STAND FOR 20
1 SEALED
i RF.AOY FOR AN W VSIS \ M > DRGANOLEPTIC EVALUATION
Ingredient
Amount
Fish flesh
Mackerel
300g
Infusion solution Polyethelyne glycol (PEG) 200
DRAINED EXCESS WATER O F F Control MIXED THROUGHLY WITH SEASONING MIXTURE t
Component
J
30 MINITES
2% (w/vv)
Sorbic acid
2% (w/w)
Butylated Hydroxy Anisole (BHA)
4 ppm
Distilled Water
100ml
Turmeric powder
2g
I
DKEP-I K1I.U VI I9O"C FOR 3 A M ) •> MINtTES
Seasoning mixture
COOLED
1 SEALED
i READY 1OR ANALYSIS AND ORCANOLEPTIC 1A ALL'ATION
Fig. 1 Preparation of Intermediate Moisture, deepfried Mackerel (Atan,M. 1981).
Garlic Shallot
1.5g
Red Chillies
lg
Ginger
0.5g
Wheat flour
4g
Table Salt (XaCl)
2.5g
Monosodium Glutamate (MSG) O.lg
Determination aw was determined by the chemical dessication method. Control and infused samples were placed in vacuum dessicators containing different saturated salt solutions and allowed to equilibrate at 29°C for 24 hours. Values obtained were interpreted by means of the graphical interpolation technique (Jayaratnam et ai, 1977).
Multiple blade cell attached to the Instron Universal Testing Machine (Model 1140). Firmness of the sample was expressed in kilogram of force required to shear the sample by a single downward action of the shear blade.
Chemical Analysis
Organoleptic Evaluation
Moisture, crude protein and ash were determined by the AOAC methods (1975). Crude fat was determined by the chloroform-methanol extraction method (Pearson, 1976).
Samples were evaluated for preferences of flavour, colour, firmness and overall" acceptability by a 10 member semi-trained panel comprising of adult males and females from the Faculty of Food Science and Technology on an 8-point hedonic scale (1 = extremely undesirable; 8 = extremely desirable). Samples were coded with three digits in a randomised arrangement to equalise the sample sequence effect on food preference.
Physical Analysis Colour was measured on the external portion of the cooked samples using the Hunter-lab Colormeter Model D25A-2 (A 4330). The instrument was standardized against a pink colour tile where ( L' (lightness) = + 67.3 'a' (redness) = + 22.6 and 'b' (yellowness) = + 11.4. Texture of the samples was determined using the Kramer
Statistical Analysis All data were analysed by the analysis of variance. Significance among the means was determined by the LSD test (Larmond, 1977). 116
SOME QUALITY PARAMETERS OF INTERMEDIATE MOISTURE, DEEP-FRIED MACKEREL
RESULTS AND DISCUSSION
Figures 2 shows the sorption isotherm curves of control and infused samples obtained after the samples were placed in equilibrium at 29°C for 24 hours. The infused samples containing the humectant polyethylene glycol (PEG) 200, butylated hydroxy anisole (BHA) and sorbic acid had lower a^'s than the control samples. The humectant binds the available free water thus reducing the aw of the product. The a obtained from the infused samples fried for 3 ancf5 minutes were 0.84 and 0.80, respectively, while those of the control were 0,90 and 0.83, respectively.
Table 4 shows the mean values for firmness in kilogram force. The samples which were deepfried for 5 minutes were significantly firmer or harder (p < 0.01) in the control and the infused samples. Firmness increased steadily with decreased a .
O)
CD
#
Control
samples
fried
for
3
minutes
A
Control
samples
fried
for
5
minutes
O
Infused
A
Infused
samples samples
fried
for
fried
for
3 5
prolonged heating in both the control and infused samples. Hunter V values for the control samples were not significantly different (P < 0.05) : however, in the infused samples the 'a' values increased significantly (P < 0.01) indicating an increase in red colouration. The Hunter 'b' values also showed a significant decrease (P < 0.01) as frying time was increased. This indicates the loss of yellow colouration with severe heat treatment. In general, with a milder heat treatment (3 minutes) samples were orange-red; with a more severe heat treatment (5 minutes) samples were reddish brown and lost much of their yellow colouration.
minutes minutes
Table 5 shows the mean panel scores for organoleptic evaluation of samples as affected by different treatments. There was no significant difference observed due to frying effect for all attributes except for firmness (P < 0.01). Flavour and overall acceptability reduced significantly (P < 0.01) between the control and infused samples. There was no significant difference for colour between the two treatments. However, for firmness, there was a similar trend for both treatments with better acceptability at shorter frying times (P < 0.01). Generally, the panelists prefered samples which were not immersed in the infusion solution, that is, the control samples.
CO
O
O)
s CO 2 CO O
0.1
t
t
.
.
0.2
0.3
0.4
0.5
a w (Water
.
0.6
i
0.7
i
i
0.8
0.9
CONCLUSION
i
1-0
This study indicates that the flesh of Mackerel can be prepared as an intermediate moisture product 'with moderate acceptance. However, more work needs to be done to improve the product in order to increase its acceptability for future market demand. Storage studies also need to.be carried out to determine the stability of the new product.
Activity)
Fig. 2. Graphical Interpolation Isotherm of Intermediate Moisutre Deep-fried Mackerel for Control and Infused Samples. Table 2 presents crude protein, crude control and infused frying. Data for raw for comparison.
mean values for moisture, fat and ash content of the samples immediately after samples were also included
ACKNOWLEDGEMENTS
The mean Hunter colour ( L\ V and 'b' values are presented in Table 3. There were significant differences in the values except for Hunter 'a* values from control samples. The Hunter 'L' values decreased (P < 0.01) with
The authors wish to thank Dr. Abdullah Abu Bakar, Department of Food Technology. Universiti Pertanian Malaysia, for his critical comments on the paper and Naimah Ahmad for typing this manuscript. 117
Y. CHE MAN, M. ATAN. TABLE 2 Proximate composition1 of intermediate moisture, deep-fried Mackerel Sample
Crude Fate
Moisture
Ash
Crude Protein
Percent Raw Flesh
74.9 ± 0.90
4.0 ± 0.90
1.3 ± 0.29
15.9 + 0.14
Control ; 3 min
57.4 ± 0.53
12.6 ± 0.45
2.5 ± 0.51
21.6 ± 0.72
Control ; 5 min
48.9 t 0.34
16.5 ± 0.07
3.4 ± 0.20
19.1 ± 0.93
Infused ; 3 min
53.6 ± 0.73
10.1 ± 0.48
1.9 ± 0.55
22.6 ± 0.82
Infused ; 5 min
48.7 ± 0.37
13.4 ± 0.20
3.2 ± 0.29
19.8
t 0.43
Mean of 9 observations with ± 1 Standard Deviation TABLE 3 Means for Hunter 'L, 'a' and 'b' colour values of intermediate moisture, deep-fried Mackerel Samples ; frying time
L
'b' Scores
Control ; 3 mins
38.23 b
10.23 a
18.93a
Control ; 5 mins
29.86 d
10.90a
13.40c
Infused ; 3 mins
41.13 a
6.20b
19.66a
Infused ; 5 mins
33.23°
11.13 a
17.90 b
Mean of 9 observations a-d
Mean within a column with different superscripts are significantly different (P 0.01)
TABLE 4 Mean for Instron firmness values of intermediate moisture, deep-fried Mackerel Samples ; frying time
REFERENCES
Firmness (kilogram force)
Control ; 3 mins
54.08 c
Control ; 5 mins
72.73
b
Infused ; 3 mins
38.74 d
Infused ; 5 mins
87.08 a
Analysis (12th ed). Washington, D.C., U.S.A. ATAN, M. (1981) : Intermediate Moisture, Deep-fried Ikan Tenggiri - its Development and Acceptability. B.Sc. thesis. Universiti Pertanian Malaysia, Serdang. COLLINS, J.L. and Yu, A.K. (1975) : Stability and Acceptance of Intermediate Moisture Deep-fried Catfish./ Fd. Set, 40: 858.
1
Mean of 6 observations ' Mcan with different superscripts are significantly different (P 0.01)
a d
118
DYMSZA, H.A. and SILVERMAN, G. (1979) : Improving the Acceptability of Intermediate Moisture Fish. Fd. Technol,
33:52.
SOME QUALITY PARAMETERS OF INTERMEDIATE MOISTURE, DEEP-FRIED MACKER] I
TABLE 5
Mean Panel Scores for the different treatments on flavour, colour, firmness and overall acceptability of intermediate moisture, deep-fried Mackerel. Samples, frying time
Firmness
Overall Acceptability
a
6.1 a
6.2a
Flavour
Colour
a
Scores Control ; 3 mins
5.5
Control ; 5 mins
6.1 a
5.4a
4.7 b
6.2a
Infused ; 3 mins
5.0b
6.1a
5.9a
5.4b
Infused ; 5 mins
4.5
5.9a
4.7 b
5.2b
F - Value
5.74
1.59r
14.51**
5.74*
5.9
lMean of 10 observations; Hedpnic Scale : 8-extremely desirable and 1-extremely undesirable for flavour, Colour and Firmness ; 8-extremely acceptable and l^extremely unacceptable for overall acceptability. a-b Pairs
of mean within a column with different supperscripts are significantly different
JAYATATNAM, K.S.,
RAMANUJA,
M.N.
(I* 0.01)
LABUZA, T.P., TANNENBAUM, S.R. and K A R E L , M
and NATH,
(1970) : Water Content and Stability of LowMoisture and Intermediate Moisture Foods. Fd. Technol., 24 : 543.
H. (1971). Water Activity in Food. J. Fd. Set Technol, 14: 129. LARMOND, E. (1977) : Laboratory Method for Sensory Evaluation of Food. Publication 1637 : Canada Dept. of Agriculture Ottawa.
PEARSON, D. (1976) : The Chemical Analysis of Food (7th ed.) London. Churchill Livingstone. {Received 17 June, 1983)
119
Pertanika 7(3), 121-122 (1984)
COMMUNICATION I
Isolation of Corynebacterium Suis from Boars in Selangor, Malaysia RINGKASAN
Satu band awal untuk prevalen Corynebacterium suis telah di jalankan ke atas dua ladang babi di Selangor. Swab prepius telah dititiskan ke atas agar darah Neomycin dan daripada ciri-ciri rupa bentuk koloni serta reaksi negatif dalam kebanyakan ujian biokimia, Corynebacterium suis telah di kenalpasti. Empat daripada 24 swab prepius temakan babi yang diperiksa didapati mengandungi Corynebacterium suis. SUMMARY
A preliminary survey for prevalence of Corynebacterium suis infection in boars was conducted on two pig farms in Selangor. Preputial swabs were streaked onto Neomycin blood agar plates and from the characteristic morphology of the colonies and inactive reactions on most of the diagnostic media, Corynebacterium suis was identified. Four of the 24 preputial swabs from the two farms were positive for Corynebacterium suis.
INTRODUCTION
RESULTS AND DISCUSSION
Cases of cystitis and pyelonephritis in pigs have been reported in increasing numbers overseas (Pijoan et al.f 1983), (Soltys and Spratling, 1957). The disease is prevalent in sows whilst boars may carry the causal organism in the preputial diverticulum without any ill-health. The disease can be a serious economic problem in individual herds as affected sows often lose weight, become emaciated and die. The causal organism, Corynebacterium suis was first described by Soltys and Spratling (1957) and since then the disease has been reported in pigs from many countries including Canada (Percy et aLy 1966), Germany ( J o n e s e* &, 1982), U.S.A. (Pijoan et al,t 1983). This communication describes the isolation of Corynebacterium suis from boars on two farms in Selangor, Malaysia.
Swabs from the preputial sac often contain several types of bacteria and Neomycin was included in the blood agar to inhibit these bacteria. Growth of Corynebacterium suis is often enhanced on Neomycin blood agar and its colonies can then be easily identified (Dagnall and Jones, 1982). The colonies after three days of incubation were large, flat, opaque, of matt appearance arid with slightly raised centres. Gram stained smears made from the colonies revealed small, gram . positive, pleomorphic organisms. The organism is rather inactive when subjected to biochemical tests (Table 1); however, it rapidly hydrolysed, urea. Our strain apparently did not produce acid from maltose as indicated by other workers (Soltys, 1961). We believe this is the first isolation of Corynebacterium suis from pigs in Malaysia. Corynebacterium suis could have been in Malaysia for a long time and being an anaerobe, it is often overlooked in routine diagnostic work in many laboratories. It is speculated that as in many other countries, the prevalence of Corynebacterium suis in male pigs in Malaysia could be high. This isolation indicates the need to examine the prevalence of Corynebacterium suis infection in boars in Malaysia and to watch for signs of hematuria in sows, especially those that have been recently mated as these could be cases of Corynebacterium suis infection.
MATERIALS AND METHODS
Sterile swabs were introduced into the preputial sac of 24 boars on two farms in Selangor and taken directly to the laboratory without the use of a transport medium. Xhe swabs were streaked immediately onto Neomycin blood agar (Dagnall and Jones, 1982). The plates were incubated at 37° in an anaerobic environment for at least three days and examined for the characteristic colonies of Corynebacterium suis. Discrete colonies were then inoculated into specific media for biochemical tests. 121
A- R. BAHAMAN, J. Y. S. LEE AND H. L. TOO TABLE 1 Biochemical reactions produced by the Corynebacterium suis isolates
Universiti Pertanian Malaysia, Serdang, Selangor, Malaysia.
Results
Biochemical Tests Urease Catalase Oxidase Blood agar — hemolysis Nitrate Citrate Gelatin Methyl Red Voges — Proskauer Oxidation — Fermentation SIM medium — Hydrogen Sulphide Indole Motility Carboyhdrate fermentation Glucose Lactose Maltose Salicin Mannitol
*
Royal Veterinary College, Potters Bar, Herfordshire, United Kingdom.
REFERENCES DAGNALL, G.J.R. and JONES, J.E.T. (1982) : A selective medium for the isolation of Corynebacterium suis. Res. Vet., Sci, 32 : 389-390. JONES, J.E.T., F A R R I E S , E. and SMIDT, D. (1982) :
Prevalence of Corynebacterium suis in wild boars and domestic pigs in the Federal Republic of Germany. Dtsch. Tieraentl wochenschr. 8 9 : 110-112.
_
PERCY,
D.H.,
RUHNKE,
H.L. and
SOLTYS,
M.A.
(1966) : A case of infectious cystitis and pyelonephritis of swine caused by Corynebacterium suis. Can. Vet. 3. 7 : 291-292. PlJOAN, C, LASTRA, A. and LEMAN, A. (1983) : Isolation of Corynebacterium suis from the prepuce of boars. J. Amer. Vet. Med. Assoc. 183: 428429. SOLTYS, M.A. (1961) : Corynebacterium suis associated with a specific cystitis and pyelonephritis in pigs. J.Path.Bact. 81 : 441-446.
A. R. Bahaman J. Y.S. Lee
SOLTYS, M.A. and SPRATLING, F.R. 1957) : Infectious cystitis and pyelonephritis of pigs: a preliminary communication. Vet. Rec. 69 : 500-504.
H. L. Too J. E* T.Jones Faculty of Veterinary Medicine and Animal Science,
(Received 7 June, 1984)
122
Pertanika 7(3), 123-126 (1984)
COMMUNICATION II
The Effect of Different Soil Types on Growth and Nodulation of Vigna radiata (L) Wilczek Inoculated with Vesicular-arbuscular Mycorrhiza (VAM) RINGKASAN
Kajian awal ini ialah untuk menguji potensi satu sampel tanah yang mengandungi spora mikoriza yang tinggi bilangannya sebagai satu unsur inokulum di dalam 4 jenis tanah : Serdang, Munchong, Malacca dan Bungor. Keputusan berat kering dan kandungan P dalam tisu daun tidak memberi perbezaan yang bermakna di antara rawatan, tetapi memberi perbezaan yang bermakna di antara jenis-jenis tanah yang digunakan. Ini mungkin disebabkan oleh jangka masa kajian ini dijalankan, terlalu singkat untuk membolehkan spesies-spesies kulat ini membiak dan menghasilkan pertumbuhan yang bermakna. SUMMARY
The potential of using a 'natural' soil with high my corrhizal spore count as a source of inoculum was evaluated in this preliminary experiment using 4 soil types : Serdang, Munchong, Malacca and Bungor. Results obtained on the dry weight and P content of plant tops was not significant between treatments but was significant between the soil types used. This could be due to the duration of the experiment being too short to enable these endogonaceous species to establish well in these soils and bring about significant growth response of the mungbean plants. to determine the growth response and hence nodule production of mungbean plants inoculated with Rhizobium and mycorrhizal spores (from the sandy beach soils) in four different unsterilized inland soils.
INTRODUCTION
Legumes need adequate phosphorus supply for satisfactory nodule production and nitrogen fixation (van Schreven, 1958, cited from Mosse, 1979). Since the root systems of legumes are relatively restricted, it has been established that these legumes respond favourably to mycorrhizal infections (Mosse, 1979). Several experiments carried out in P-deficient soils have shown improved nodulation and nitrogen-fixation on inoculation of the plants with mycorrhiza (Abbott and Robson, 1977; Crush, 1974; Mosse et al.t 1976). Mosse (1979) has also shown that in Centrosema, only mycorrhizal or P treated seedlings produce nodules. Without any of these, no nodules were produced in spite of a reasonably well-developed root system.
MATERIALS AND METHODS
This pot experiment was conducted in four unsterilized soils namely : the Serdang and Bungor series (Typic Paleudult) and the Munchong and Malacca series (Tropeptic Haplorthox). Table 1 gives the physicochemical properties of the four soil types used. Three of the soils have pH 4.7 except Munchong with pH 5.2. Twentytwo cm diameter pots were used for the experiment, each pot containing 5 kg soil. Urea, triplesyperphosphate and muriate of potash were applied to each pot (top-dressing) at the equivalent rate of 50 kg N, 100 kg P and 120 kg K per ha respectively. There were four treatments per soil type : (1) uninoculated control, (2) inoculated with VA mycorrhizal fungus (comprising mixed species from sandy beach soil), (3) inoculated with Rhizobium compost of variety CV 5000 (obtained from RRIM) and (4) inoculated with (2) and (3).
It has been demonstrated by Harley (1969) and Gerdemann (1975) that inoculation of forest trees and agricultural plants with mycorrhizal fungi can stimulate their growth in nutritionally poor soils. Such soils occur in very large areas of the tropics. The possible impact of mycorrhizas seems obvious from the observation that almost all plant species of economic importance in the tropics are infected with VA endophytes (Crush, 1974; Mosse et aL, 1976; Ross and Harper, 1970). In the light of the present knowledge, this preliminary investigation has been initiated
The soaked mungbean seeds (of uniform size 4mm x 5 mm ± 2mm) were mixed with the 123
AZIZAH CHULAN (HASHIM) A.J.M. KAMAL AND M. OMAR TABLE 1 Physicochemical properties of the four soil types used
Horizon
Serdang
Manchong
Malacca
Bungor
AP
Ap
Ap
Ap
+Depth (cm)
0-15
0 10
0-10
0-15
+Coarse sand (%)
35.1
7.7
16.7
16.8
+ Fine sand (%)
31.9
27.8
5.5
53.1
+Silt (%)
7.4
13.3
17.6
11.4
+Clay (%)
25.6
51.2
60.2
18.7
Organic carbon (%)
1.30
2.35
1.44
2.46
Total N (%)
0.10
0.23
0.18
0.11
Extractable P (ppm) pH (0.1 X CaCl 2 )
36.6
21.1
15.3
12.70
4.7
5.2
4.7
4.7
+S. Paramananthan (1978) Rhizobium compost before sowing. At the time of planting, 50g sandy beach soil (containing about 100-200 viable VAM spores) were placed at about 5 cm below the top-soil in each pot. The seeds were then planted 2 cm above the inoculum soil at an average of 4 seeds per pot. The uninoculated plants were similarly treated using 50g autoclaved sandy beach soil. The plants were thinned to two per pot 2 weeks after sowing. Five replicates were used for each treatment.
the level of inoculum added was insufficient to bring about significant plant response within the short period the experiment was conducted (35 days). The best overall growth response was by plants growing in the Malacca series and the poorest was shown by plants grown in the Munchong series. The difference in top dry weights of plants between treatments were not significant (Table 2). Only the difference between soil types was significant.
The plants were harvested 35 days after sowing (when 80% of them had produced flowers). The number and size of nodules per treatment were measured and recorded. The plant tops were oven-dried at 60°C for 72 hours and their dry weights determined. Subsamples of the ground tissue were digested with concentrated sulphuric acid and 50% hydrogen peroxide (Thomas et al, 1972) and analysed for N, P and K on a Technicon * R ) Autoanalyser.
Nodule Distribution In general, the size and distribution of nodules within the root-zone of the test crop was influenced more by the physical properties of the different soil types used rather than by the treatments given. Plants grown on the Serdang soil gave bigger (2—3 mm diameter) but fewer nodules (42—70 nodules/plant) compared to smaller and more numerous nodules (68—152 nodules of 1 — 1.5 mm diameter) produced in the Malacca soil. Most of the nodules in the Serdang soil were produced on the upper part of the lateral roots (about 40 cm from the crown) while in the Malacca series, pin-sized nodules were produced as deep as 10 cm from the crown along the length of the lateral roots. There was very poor nodulation in plants grown in either Bungor or
RESULTS AND DISCUSSION Growth Response Inoculation of plants with both Rhizobium and mixed mycorrhizal species did not seem to enhance plant growth when compared to plants receiving either one or no inoculation at all (Table 2). This could perhaps be due to the introduced endogonaceous species not being able to establish well in the four soils tested or that
124
THE EFFECT OF MYCORRHIZA INOCULATION AND SOIL TYPES ON GROWTH AND NODULATION OF VIGNA R ADI AT A
TABLE 2 Effect of inoculation with VA endophytes and Rhizobium on the dry weight (g) of tops of mungbean 35 days after sowing. The differences due to soil series are significant (P