Theses

Browse

Search Results

Now showing 1 - 9 of 135

Open Access
Comparative micromorphologial and physico- chemical study of the upland and midupland laterite soils of Kerala
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1986) Sankarankutty Nair, R; KAU; Aiyer, R S
Open Access
Estimation of induced variability in chillies
(Department of agricultural botany , College of agriculture Vellayani, Trivandrum., 1985) Lekha Rani, C; KAU; Krishnan Nair, N
The mutagenic effect of Co-gamma rays and Ethylmethane sulphonate on three different chilli varieties have bean studied in detail in generation U3 ing two moderate doses of gamma rays <20 and 30 kR) and two concentrations of ISMS (0.5 and 1*0 par cent)* The presence and extent of chimeras and their relation to induced variability was assessed by raising branch-wise progenies in ^ generation* The experiment was conducted during 1982-84 at the Department of Agricultural Botany# College of Agriculture, Vellayani* The generation was laid out in RBD and in splitplot design with proper randomisation and replications* The crop wa3 raised and maintained following the Package of Practices recommended. The polygenic traits analysed in a, generalisen include plant height, number of branches per plant, fruit yield per plant and length and weight of fruits. The data collected were statistically analysed for proper interpretation of tho results obtained. It has been observed in almost all the polygenic traits that the extent of variability created vary depending on the genotypes, mutagen and their dosos and character under observation. The mean values wer« found to shift both in negative and positive directions to control values• significant shift in mean values depending on the type of branch category clearly demonstrates that there exists the mechanism of diplontlc selection in this particular crop variety# when exposed to mutagens. But the extent of selection varies depending on the mutagen and their doses and the genotypes concerned. a significant negative shift in mean Value was noted only in the case of fruit weight under both the concentrations of EM3 and 20 kR gamma rays whereas a positive or negative insignificant shift was noted in all other characters under both the mutagens, when under EM3 and in gansna rays showed a negative shift* positive shift in mean value wes noted in majority of the cases for number of branches per plant. Fruit length and weight and number of seeds per fruit showed a negative shift in majority of the cases analysed# but fruit number and yield per plant showed a reverse trend. The shift in mean value under the different branch categories varied depending on the varieties# mutagens and their doses and also the character under study. The phenotypes were found toAdistributedboth in negative and positive directions to control group in all the characters analysed. The frequency distribution whether negative or positive varied depending on the mutagen and their doses# the genotypes and character under study. In majority of tha cases the maximum frequencies of positive variants under both the concentrations of EMS and under 0.5 per cent for negative variants were found to be in the early formad branches when it was in the later ones is tha case of negative variants under 1.0 per cent EMS. in the case of gamma rays this general trend was not observed* The data analysed clearly demonstrate the existence of diplontic selection and promises wide scope for positive selection response either in negative or positive directions.
Open Access
Study of genetic correlations under full -SIB mating system (Two loci case)
(Department of Statistics, College of veterinary and animal sciences Mannuthy, Thrissur, 1985) Khin Moe Moe; KAU; George, K C
A purely theoretical investigation entitled ,JA Study of Genetic Correlations under Fu ll-s ib Mating System (two lo c i case)*1 was carried out with the following objectives, i ) to derive the joint distribution (correlation table) and to find the correlation between fu ll -s ib pairs under fu l l -s ib mating system in the case of two lo c i when there i s no linkage as well as when there i s complete linkage. l i ) to derive the joint distribution (correlation table) and to find the correlation between parent-offspring pair© under fu l l -s ib mating system in the case of two loci when there is no linkage as well as when there is complete linkage, i i i ) to derive the joint distribution (correlation table) and to find the correlation between fu l l -s ib pairs under paront-offspring mating system in the case of two lo c i when there is no linkage as well as when there is complete linkage, iv) to derive the joint distribution (correlation table) and to find the correlation between parent-offspring pairs under parent-offspring mating system in the case of two lo c i when there is no linkage as well as when there is complete linkage. 2 Th© joint distributions of fu ll -s ib pairs and parent- ©Ffspring pairs undor fu ll-s ib gating system wore derived with the help of generation matrix technique and th© correlations wore worked out therefrom, assuming additive genie e ffec ts and using the product-momeni correlation coefficient formula. The correlations were worked out for tho f i r s t ten generations of fu ll -s ib mating in both cases of no linkage and complete linkage, & comparative study of fu ll -s ib correlations and parent-offspring correlationsf conducted both numerically and graphically, revealed that £i) evonthough fu ll -s ib correlation was greater than parent-offspring correlation in in i t ia l generation (random mating) when there was complete linkage, the la tte r increased more rapidly than the former from in it ia l generation to f ir s t generation and ( i i ) from the second generation onwards, the rate of increase in both o f correlations were nearly the same upto tenth generation. I t was interesting to note that the parent-offspring correlations wore of comparatively higher order than th© fu ll-s ib correlations in both cases of complete linkage and no linkage. Similarly, th© joint distributions (correlation tables) for fu ll-s ib pairs and parent-offspring pairs under parentoffspring mating system were derived employing generation matrix approach and the correlations for the f i r s t ten 3 generations of parent—offspring mating in both cases of no linkage and complete linkage were worked out therefrom. A comparative study of those correlations was carried out both numerically and graphically. It was found that the trend in both correlation curves remain the same, but the value of parent-offspring correlation was always greater than that of full-sib correlation in case of no linkage as well as in caso of complete linkage. In comparison of all these correlations, it was found that the correlations increased as the number of generation increased and ultimately reached the limit unity when the number of generations increased indefinitely large. It was also observed that the magnitude of correlation in case of complete linkage was more than that of correlation In case of no linkage even under the same system of mating*
Open Access
Impact of the coconut rehabilation programme of SADU in Trivandrum district
(Department of Agricultural Economics, College of Horticulture, Vellanikkara, 1984) Lekshmi Narayanan Nair, N; KAU; Radhakrishnan, V
This study was conducted in 1983 to assess the impact of the Coconut Rehabilitation Programme implemented in Trivandrum District as part of the World Bank assisted, Kerala Agricultural Development project. The specific objectives were to examine the extent of utilization of loans, the improvements in cropping pattern and farming practices, changes in yield rates and output and the increase in farm income generated by this programme. The relative efficiency of irrigation and the various intercrops in augmenting the net farm incomes of the participating farmers was compared and the major constraints in improving coconut farming in the district were also identified as a part of this study. Data were collected from a sample of 96 participating farmers selected at random from the 14 Package Units functioning in the district under this project through personal interview using a well structured schedule. The main findings of the study are summarized below. Majority of the holdings (51.03 per cent) were in the category of less than 0.80 hectare but they accounted for only 27.36 per cent of the area covered. Holdings of 0.80 hectare and above predominated (59.26 per cent) in the category of irrigated holdings. About 49 per cent of the households depended on non-agricultural pursuits for their main source of income. Eighty per cent of the families were relatively small in size with a membership of less than 7. The overall average investment estimated, sanctioned and spent per hectare for the 96 holdings under study worked out to Rs. 17923.05, Rs.14393.67 and Rs.14959.57 respectively. Though the overall performance in respect of loan utilization was satisfactory, there was shortfall in utilization of loans under Cocoa (58 per cent), coconut gapfilling (41 per cent), purchase of Cows (23 per cent) and Fodder Development (17 per cent). The percentage of utilization of loans in the case of unirrigated category was low (50.18) compared to the irrigated category (122.43). Among the lending institutions through which the National Bank for Agriculture and Rural Development funds were channelised, Primary Co-operative Land Mortgage Bank was the most acceptable agency (61 per cent). The cropping intensity of the sample increased from 111.77 per cent to 189.87 per cent consequent on the implementation of the programme. The area under coconut, banana, cocoa and fodder increased while that under tapioca decreased. The density of coconut palms increased from 125 palms per hectare to 176 palms. This is against the project objective of attaining an optimum stand of 175 healthy and high-yielding coconut palms. By and large the target set for intercropping programme as per the individual farm production plans has been achieved. The target was exceeded in respect of banana (119.3 per cent) coconut (103.34 per cent) and cocoa (101.2 per cent). Tapioca continued to be the intercrop widely preferred by the coconut growers (192.75 per cent). Shortfall was mainly in the coverage of area under fodder (18 per cent) and livestock to be purchased (36 per cent). The project has been instrumental in stepping up substantially the level of use of various inputs including irrigation. Fifty four holdings had the benefit of irrigation covering 62 per cent of the net area covered by the sample, while in 13 cases though irrigated development was contemplated, it had not been successful due to operational constraints such as failure to obtain electric connection, failure of wells etc. The average cost of a pumpset with accessories worked out to Rs. 8717.68 while the average amount sanctioned under the lending programme was only Rs.7715 per pumpset. The intensity of senile and uneconomic palms as revealed by the study was only 3.6 palm per hectare against the projection of 20 palms per hectare assumed in the project report. Out of 388 palms identified for cutting and removal only 77 were actually removed. Though the target in respect of gap filling has been exceeded by planting 4790 seedlings against the target of 4762 seedlings, the maintenance of the seedlings was not upto the standard. The increase in use of organic manure for coconut from 17 to 48 kg per palm is commendable. But the use of organic manure for the intercrops is deplorably low especially for banana (6 kg per plant) cocoa (3 kg per plant) fodder (2200 kg per hectare) and tapioca (3698 kg per hectare). Fertilizer application for coconut has increased from 0.22 kg to 1.52 kg per palm. The average fertilizer dose of 0.08 kg per cocoa plant 0.25 kg per banana plant, 33 kg per hectare for fodder and 113 kg per hectare for tapioca as adopted by the participants were also inadequate. Only 6 out of 96 holdings covered under the survey have adopted plant protection measures. The intensity of cultural practices has increased many fold with the biggest increase for coconut (562 per cent). All the crops except tapioca have registered substantial increase in total production. Banana, coconut and milk production registered increases of 677 per cent, 62.45 per cent and 15 per cent respectively. Production of tapioca declined by 25.6 per cent. The increase in productivity of coconut was only 38 per cent over the productivity at the pre-project level. In absolute terms the productivity of coconut has increased from 25 nuts to 30 nuts per palm in the unirrigated holdings while the increase in irrigated holdings was from 30 nuts to 44 nuts per palm. The overall increase was from 29 to 40 nuts for the sample as a whole. The increase in yield was highest in the holdings which have completed 5 years (67 per cent) of development followed by holdings completing 4 years (31 per cent) and 3 years (29 per cent). The post project average yield of intercrops such as cocoa (Rs.59 per hectare) banana (6.95 kg per plant) fodder (4525 kg per hectare) and tapioca (5055 kg per hectare) was considerably low. The average gross income per holding increased from Rs.4478 to Rs.9224. In per hectare terms the increase was from Rs.4613 to Rs.9502 (105 per cent). The average net farm income rose from Rs.2860 to Rs.3821 per hectare (34 per cent). The increase in net farm income was maximum in the case of holdings which had completed 5 years of development (69 per cent) followed by holdings completing 4 years (32 per cent) and 3 years (20 per cent). An increase of 47 per cent in the average yield of coconut, 62 per cent in fodder, 0.47 per cent in banana, 134 per cent in cocoa and 17 per cent in milk was notices under the irrigated holdings over the unirrigated holdings. Comparative analysis of the different intercrops indicated that banana is the most profitable intercrop in coconut gardens in Trivandrum district with a potential net return of Rs.6015 per hectare. Mixed farming with dairying as one of the components, though successful in holdings of more than 0.8 hectare size, ranks only second in order of profitability, with a net income of Rs.2990 per hectare. Tapioca with an average return of Rs.621 per hectare ranks third in the order of profitability. Cocoa, the fourth intercrop compared showed negative returns at the yield and price levels prevailed. Economic uplift of the coconut growers by augmenting farm income through whole farm development approach had been the basic objective of the project. On the whole the project has made a good beginning in this direction in spite of several operational constraints.
Open Access
Effect of growth regulators on flowering pollination and seed-set in ginger(zingiber officinale, rose)
(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1984) Usha, K; KAU; Balakrishnan, S
Flowering behaviour and floral biology of Rio-de-Janeiro and Maran and the effect of growth regulators viz., kinetin (5, 10 and 15 ppm), Ethrel (25, 50 and 100 ppm) and NAA (10, 25 and 50 ppm) in combination with two per cent urea and without urea on flowering, pollination and seed-set in Rio-de-Janeiro were studied at the College of Horticulture, Kerala Agricultural university, Vellanikkara during 1981-’83. The objective of the investigation was to assess the available varieties of ginger for flowering behaviour and to evaluate the effect of growth regulators with and without urea on the flowering behaviour, floral biology, floral structure, pollination and seed- set in Rio-de-Janeiro. (The possibility of overcoming the problems of shy and irregular flowering, poor pollen germination and the failure to set seeds also was explored during the investigation). (Among the 25 varieties studied, flowering was observed only in two varieties viz., Rio-de-Janeiro and Maran). Considerable variation was noticed between Rio-de-Janeiro and Maran with respect to flowering behaviour, extent of flowering, types of inflorescence, time taken for scape development, anthesis, anther dehiscence, pollen production, pollen fertility, style length and ovary length. Long but thin style was noticed both in Rio-de-Janero and Maran. Irrespective of the variety, flowers were found to rot/ and dry within 16 hours after flower opening. The maximum pollen germination (6.20 per cent) was obtained in the medium containing eight per cent sucrose, three per cent gelatin and 60 ppm boric acid under moist cotton covering in BOD incubator (26.50C). Coiling of the pollen tube during the advanced stages of growth was noticed. Pollination carried out in Rio-de-Janeiro and Maran employing the variables like stage of flower (bud stage, immediately after flower opening and three hours after flower opening), condition of stigma (partial and complete removal of style), density of pollen (smearing once, twice and thrice with standard brush), mixed pollen (ginger pollen with either Alpinia, Hedychium, Kaempheria or Costus pollen) and supplementary pollination (repeated pollination twice at two hours interval) failed to record any positive evidence of seed-set. Effect of growth regulators and urea on flowering behaviour, inflorescence characteristics and floral structures of ginger was evidenced during the study. ( Favourable influence of NAA 50 ppm on inducing early flowering, kinetin 15 ppm on the duration of flowering, NAA and kinetin on inflorescence production, NAA 50 ppm without urea on the number of flowers per inflorescence, NAA 10 ppm and all the three levels of kinetin on pollen production, NAA on pollen diameter, higher levels of Kinetin and Ethrel and lower levels of NAA on exine thinning, Ethrel 25 ppm in combination with urea, Kinetin 15 ppm with urea, NAA 50 ppm and Kinetin 10 ppm on pollen fertility, lower levels of Kinetin and Ethrel on reducing the style length, Kinetin 15 ppm and NAA 10 ppm on ovary length, Ethrel 25 ppm with urea and higher levels of NAA and Kinetin on pollen germination and NAA 50 ppm on pollen tube growth was revealed during the study.) Floral biology of Rio-de-Janeiro was not influenced by growth regulator and urea treatments. Abnormal floral structures occurred as isolated cases and therefore the role of growth regulators and urea in this respect was not clear from the results. (Pollination carried out in ginger (var.Rio-de-Janeiro) plants, subjected to growth regulator treatments with and without urea, employing the variables like stage of flower, condition of stigma, density of pollen, mixed pollen and supplementary pollination failed to result in seed-set.)
Open Access
Varietal screening of banana against anthracnose disease
(Department of Plant Pathology, College of Horticulture, Vellanikkara, 1984) Srinagesh, K L; KAU; Jose, P C
Laboratory and field studies of the varietal screening of banana against anthracnose disease were conducted at the college of Horticulture. Vellanikkara and at Banana Research Station, Kannara respectively during 1981-1983. In the field the infection started at the distal end of the banana fruit and in course of time the infected fruit became blackened, shriveled and mummified. After Harvest, the symptoms appeared as small brown spots which enlarged quickly and coalesced forming larger patches. The affected areas were covered with orange to salmon pink coloured conidial masses. The detailed morphological studies of the fungus proved that the anthraemose disease of banana is caused by colletrichum cloeosporioides cooko and massee, the imperfect stage of glomerella cinoulata spauld and shrenk. Twenty five varieties of banana fruit were screened in vitro at different stages of development against anthracnose disease. The varieties showed different degrees of susceptibility at various developmental stages of the fruit. The pooled analysis of the data showed that the variety nendra padaththi followed by palayankodan, jurmani kunthali, boodida bontha bathes, peyan, kanchikela, pisang mas and kapok were found to be highly resistant. The varieties Zanzibar, adakka kunnan, klue teparod, chinia, nendran, venneettu mannan, koduppilla kunnan, hybrid sawai, poocha kunnan, red banana and boodles altafort were found to be resistant to the disease. The variety robusta was found to be susceptible. The varieties njalipoovan, pisang lilin, dwarf Cavendish, matti and gros Michel were found to be highly susceptible. The major chemical constituents of banana fruit viz. reducing sugars, total sugars starch, crude fibre, crude protein and tannin at different developmental stages of twenty five varieties were analysed. The reducing sugars and total sugar were found to increase steadily from immediately after female phase to ripened stage in all the varieties. The starch and crude fibre contents, though increased steadily upto full maturity. Declined sharply at the ripening stage. The crude protein and tannin contents were maximum at immediately after female phase but steadily decreased and were minimum at ripening phase. There was a significant positive correlation between reducing sugars, total sugars and per cent disease intensity at three fourth maturity. High sugars were responsible for susceptibility to the disease. A significant negative correlation was obtained between crude protein and per cent disease intensity at half maturity. A significant negative correlation was also obtained between tannin and per cent disease intensity at one fourth and half maturity stages. High crude protein and high tannin contents were responsible for resistance to the disease.
Open Access
Cellular and humoran immune responses to corynebacterium presudotuberculosis infection in goats
(Department of microbiology, College of veterinary and animal sciences, Mannuthy, 1986) Jayaprakasan, V; KAU; Sulochana, S
Caseous lymphadenitis was experimentally produced in cross-bred malabari goats aged 8 to 12 months by bilateral inoculation of 1 x 106 viable C. pseudotuberculosis (ATCC 19410) through intradermal, subcutaneous and submucosal routes. The clinical picture, immune response and pathological features were studied up to a period of 13 weeks. The development of immune response in experimentally infected goats was assessed, by comparing the data with those of the controls, with respect to total serum protein, serum protein fractions, antibody activity of the serum, leukocyte count, counts of lymphocyte subpopulations, leukocyte migration inhibition index and skin hypersensitivity reaction. Pathological features in the lymphnodes and other tissues of infected goats necropsied at 15 days interval were also studied. Initial febrile reaction which lasted for 72 to 96 h, local inflammatory changes caused at the site of inoculations during the first two to three weeks of infection and the development of lesions typical of caseous lymphadenitis in local/regional lymphnodes within 21 days post-inoculation were the main features of clinical manifestations of the disease. aS a result of infection, neutrophilic leukocytosis was maximum during the 2nd week of infection. No appreciable was maximum during the 2nd week of infection. No appreciable change in counts of other cells in terms of their absolute numbers was noted during the entire period of observation. The humoral immune response in infected goats was indicated by the rise in serum protein, antitoxic antibody and B-lymphocyte count in the peripheral blood. The serum protein concentration increased to significant levels from the 5th week onwards and it reached the peak value (11.346 g%) by the 8th week. From the 3rd week onwards haemolysis inhibition test, which detected goats and persisted till the end of the observation period. The peak antibody level was recorded by the 5th week of infection and thereafter there was gradual reduction in the titre. Significantly high percentage of B- lymphocyte was recorded in infected animals from the 2nd to 10th week, except at the 5th week. The percentage of B-cells in infected goats ranged between 12.3 + 0.85 – 17.63 + 1.2 while it was 8.56 + 0.75-12.3 + 1.09 in control goats. This was considered as an indication of stimulation of humoral immune response. The cell-mediated immune response was evidenced by the increased T- lymphocyte count in the peripheral blood, inhibition of leukocyte migration and the development of delayed skin hypersensitivity. The mean percentage of T-lymphocytes in the peripheral blood of infected goats by E-rosette assay recorded an initial reduction at the first week (18.44 + 1.4) followed by an increase which was significant during the 5th, 6th, 7th, 8th, 12th and 13th week of infection. The maximum value was recorded (35.24 + 1.58) at the 13th week. In the case of control goats the percentage values ranged from 24.55 + 3.66 to 26.74 + 1.34. The T-lymphocyte count in the peripheral blood enumerated the ANAE method did not show any significant change even after infection. In the experimentally infected goats, leukocyte migration inhibition index was less than 0.8 during post-infection period while the control goats had the index value above 0.8. Significant reduction in the migration index was noted by 45th day of infection and the maximum reduction was on the 60th day. Intradermal injection of the toxic supernatant of the culture elicited characteristic delayed skin hypersensitivity reaction in all the experimentally infected goats while there was no reaction in the controls. The positive reaction was found to be maximum by the 48th hour post-injection. The pathological changes were characterized by an initial stimulatory hyperplastic reaction in the lymphnodes and this was accompanied by necrobiotic changes typical of caseous lymphadenitis. The hyperplastic stimulatory reactions were characterized by the presence of several active follicles with well developed germinal centres in the cortex, distinct medullary cords densely lined with plasma cells and sinus histiocytosis indicating the early elicitation of humoral immune response to the bacterium or to its in vivo products. The results obtained from the present study revealed the operation of both cell-mediated and humoral immune responses in goats against C. pseudotuberculosis infection. Of the various methods employed to monitor the immune response, leukocyte migration inhibition and delayed skin hypersensitivity tests were found to be of value in assessing the cell-mediated immune response and haemolysis inhibition test for humoral immune response. Leukocyte migration inhibition test and haemolysis inhibition test could be employed for early diagnosis of C. pseudotuberculosis infection in goats. FINDINGS : The immune responses and pathological features in Corynebacterium pseudotuberculosis infection were studied by experimental infection of cross- bred Malabari goats of S-12 months of age. Single cell bacterial suspension in chilled sodium chloride bile salt solution was used for this purpose. Goats were inoculated at both sides of the body by three routes viz., intradermal, subcutaneous and submucosal, with 2 x 106 bacteria per site of injection. The experimentally infected and control goats were observed for clinical manifestations of caseous lymphadenitis for a period of 13 weeks. The development of immune response in experimentally infected goats was assessed by comparing the data with those of the controls with respect to total serum protein, serum protein fractions, antibody activity of the serum, leukocyte counts, counts of lymphocyte sub-populations, leukocyte migration inhibition index and skin hypersensitivity reaction. Gross and histopathological changes in the lymphnodes and other tissues of necropsied goats were studied at 15 days interval for a period of 90 days. All experimentally infected goats exhibited rise in temperature, general weakness, lethargy and impaired appetite which lasted for 72 to 96 h. The sites of inoculations showed varying degree of inflammatory reaction during the first two to three weeks of infection. All experimentally inoculated goats except one developed lesions typical of caseous lymphadenitis in regional/local lymphnodes within 21 days post-inoculation. Route of infection did not influence the ability to set up lesions in lymphnodes. Although massive dose of bacterial (1.2 x 107) was administered, none of the goats had fatal infection indicating that goats are relatively resistant to this infection. Majority of goats did not develop generalized form of caseous lymphadenitis as there was no lesions in visceral/deep seated lymphnodes or organs. The normal serum protein concentration of cross-bred Malabari goats was estimated to range from 7.187 to 9.750 g %. Consequent to experimental infection, serum protein concentration was increased and recorded significant rise from the 5th week onwards reaching the peak value by the 8th week – 11.346 g%. Estimation of quantitative distribution of serum protein fractions was done by agar gel electrophoresis and densitometer tracing of electrophoretogram. Though there was initial increase in globulin content in infected animal followed by a decrease, no significant alteration in the albumin-globulin ration (A:G ratio) was noted compared to the control group. C. psuedotuberculosis was cultivated in lemco proteose broth containing sheep serum and incubated aerobically at 370C for 72 h. Supernatant obtained from the above culture, having maximum haemolysin titre and dermonecrotoxicity was used as the toxin of the bacterium in the present studies. The haemolysin content of the culture supernatant was estimated by the haemolysis test using sheep red cells. A maximum titre of 1:256 was found in the culture aged 72 h. The dermonecrotoxicity of the toxic culture supernatant was tested by intradermal inoculation into the rabbit skin. The inflammatory and necrotic reactions were maximum by 48 h post-injection. Specific antibody activity against toxin of C. pseudotuberculosis in the serum was monitored by haemolysis inhibition test and the test was adjudged as a useful test for detecting humoral immune response to C. pseudotuberculosis infection in goats. In infected goat from the 3rd week of infection onwards MIT was positive while it was negative in control goats during the period of 13 weeks of observation. The peak antibody level was achieved by the 5th week of infection and thereafter the titre was found to dwindle gradually till the 11th week. Towards the end of the observation period (12th week) there was a marginal increase in the antibody titre, which would be considered as secondary immune response against the toxin of the multiplying bacteria. Infected goats showed leukocytosis during the entire period of observation and maximum leukocytosis was observed during the 2nd week of infection. The periodical fluctuation in leukocytosis indicated the recurrent flare up of bacterial invasion in the body. The absolute lymphocyte count obtained both at pre and post-infection periods with experimentally infected goats did not show any change which indicated no deleterious effect on peripheral blood lymphocytes. Throughout the period of observation infected animals showed numerically low lymphocyte percentage in differential counts and with several samples the percentage distribution was significantly low. Absolute counts of neutrophils were consistently high in experimental goats when compared to those of controls and the same was reflected in differential count also. The other blood cells were absolutely without any change in infected as well as control goats. Density gradient centrifugation using Ficoll-paque (1.077 g/ml, centrifuged at 720 x g) was found quite useful for separation of mononuclear leukocytes from the whole blood of goats. Such separated mononuclear cells were found to contain on an average 91.80% lymphocytes and 8.2% monocytes with an average viability of 91.2%. Peripheral blood B-lymphocytes of goats were successfully enumerated by EAC rosette assay employing bovine red cells. The normal percentage of B-cells was estimated to range 8.56 and 12.3. Significantly high percentage of B-cells was recorded in infected animal from the 2nd to 10th week post- infection except at the 5th week. B-cell percentage in infected goats ranged between 12.3 + 0.85-17.63 + 1.2 while it was 8.56 + 0.75 to 12.3 + 1.09 in control goats indicating the operation of humoral immune response to concurrently boost the specific antibody activity in the serum. T-lymphocytes of goats were identified and enumerated by E-rosette assay and ANAE activity. Goat lymphocytes presented several receptors to sheep red cells, as majority of rosettes presented erythrocytes at the entire periphery of lymphocytes. The mean percentage of E-rosette positive lymphocytes in the peripheral blood of control goats ranged from 24.55 + 3.66 to 26.74 + 1.34 during 13 weeks of observation. The E-rosette technique employed in the present study was assumed unaffected by unknown variables as the data recorded in the control goats remained near normal throughout the observation period. During the first two weeks of infection E-rosette positive lymphocyte count was found numerically decreased and the reduction was significant at the first week (18.44 + 1.40). From the third week onwards an increase in the E-rosette forming cells was observed and significant increase was noted during the 5th, 6th, 7th, 8th, 12th and 13th week of infection, the maximum being at the 13th week (35.24 + 1.58). T-cells were also identified and enumerated based on the demonstration on ANAE activity. Fixing of mononuclear cells in acetone-citric acid solution enabled the fixed smears to be stored in dry state without any interference to the enzymic activity for longer periods. T-lymphocytes presented one or two localized red coloured reaction product in the cytoplasm adjacent to the cell membrane. Mean percentage of ANAE positive cells in experimental goats was 28.09 + 1.51 while it was 35.80 + 4.86 for control goats when estimated before the start of the experiment. During infection, the count of ANAE positive cells in the peripheral blood did not show any change as the mean percentage ranged between 28.9 + 2.06-33.78 + 1.99 as against the corresponding values (30.83 + 3.5-36.91 + 3.61) in controls. In infected animals significant hike in E-rosette positive lymphocyte counts was recorded while such a change could not be observed with ANAE positive lymphocytes. Thus the results of T-cell estimation by E-rosette assay and ANAE demonstration indicated that estimation of total rosette forming cells could reflect better the T-cell competence. Cell mediated immune response to C. pseudotuberculosis infection in goats was demonstrated by leukocyte migration inhibition test under agarose. A population density of 1.5 x 108 leukocytes/ml was found suitable for LMIT. Toxic culture supernatant having haemolysin titre 1:16 whose pH adjusted to 7.2 could be successfully used as antigen in the test. In experimentally infected goats leukocyte migration index was less than 0.8 during post-infection period while with control goats it was above 0.8. Significant reduction in LMI index was noted by 45th day of infection through 75 days showing maximum reduction by the 60th day. Intradermal injection of toxic culture supernatant elicited characteristic delayed type skin hypersensitivity reaction in all experimentally infected goats, while a negative reaction in controls. Skin hypersensitivity reaction was found to be maximum by 48 h post-injection. Histopathology of skin biopsy taken from the site of inoculation revealed infiltration of lymphocytes, and macrophages at perifollicular and periglandular areas, congestion of blood vessels with perivascular infiltration of lymphocytes and macrophages and dermal oedema. Tuberculin failed to produce a positive skin hypersensitive reaction in C. pseudotuberculosis infected or control goats. From 15th day onwards, experimentally infected goats which were necropsied presented gross lesions typical of caseous lymphadenitis in lymphnodes. The lesions were found to confine to superficial lymphnodes adjacent to the site of inoculations. The histological changes observed in lymphnodes were basically of two types: hyper-plastic stimulatory reaction and degenerative changes. The changes were hyper-plastic reactive follicles with well distinguished germinal centre, accumulation of lymphocytes and varying degrees of sinus histiocytosis in medullary region, dense lining of medullary cords with plasma cells, depletion of lymphocytes from the cortical area; subcapsular and cortical oedema, congestion of blood vessels, haemorrahage, infiltration of mononuclear cells in lymphatics and blood vessels, accumulation of macrophages and plasma cels in the medulla, dilatation of sinusoids, fibrous tissue proliferation, degenerative and necrotic changes of lymphocytes in the cortex and medulla, fibrous tissue encapsulated focal areas of caseation of calcification surrounded by lymphocytes, macrophages and giant cells and finally conversion of parenchyma to a caseated mass enclosed in fibrous tissue capsule. In brief, the results obtained from the present study revealed the operation of both cell-mediated and humoral immune responses in goats against C. pseudotuberculosis infection. Of the various methods employed to monitor the immune response, leukocyte migration inhibition and delayed skin hypersensitivity tests were suitable for ascertaining the cell-mediated immune response and haemolysis inhibition test for humoral immune response. Leukocyte migration inhibition test and haemolysis inhibition test can be successfully employed for the early diagnosis of C. pseudotuberculosis infection in goats.
Open Access
Design and development of a propeller pump
(Department of Agricultural Engineering, College of Horticulture, Vellanikkara, 1984) Sasi, K; KAU; Remadevi, A N
“Petti and Para” a crude form of Axial flow pump is used in Kerala for dewatering agricultural fields. It is being fabricated by local blacksmiths and there is no scientific design for the pump. For low head high discharge conditions Petti and Para is very effective, but less efficient because of faulty construction. The broad objective of the project was to develop an axial flow pump with improved efficiency which could be economically used for dewatering and for lift irrigation purposes under low head conditions. In this investigation, a good amount of attention was given to the fluid dynamics inside the axial flow pump and theoretically studied the combined affect of various parameters involved in the design of an axial flow pump. Then the parameters were compared with the approximate values given by the various researchers in the field. The requirement of the pump to be designed, at field conditions, were studied thoroughly and an one dimensional design was done. After designing and fixing the dimensions, the pump was fabricated in the Kerala Agricultural University Research Workshop at Mannuthy. Because of the lack of facilities in the Research Workshop, it was tested in the hydraulics laboratory at the Government Engineering College, Trichur. The power unit used was a 15 HP electric motor. The accessories used to measure discharge and head were a rectangular notch with Hookgauge and water manometer respectively. Testing was done with two levels of water above the impeller, one 20 cm above the impeller and the other 10 cm above the impeller. For the above two conditions, at designed head (1.5m) the maximum efficiencies obtained were 33 per cent and 29.5 per cent at discharge 121 lit/sec. and 114 lit/sec. respectively. The maximum working capacity was 165.19 lit/sec. against a head of 1 m with an efficiency of 31.95 per cent (20 cm above the impeller) In the three bladed pump, the blades were fixed to the hub by welding it to the suitably shaped (curved) M.S flats and then bolting the curved M.S. flats to the hub. The blades were twisted from 160 to 240 in a uniform variation by simple blacksmithy. The efficiency of the pump can be increased by using perfectly curved blades, which reduces eddies and skin friction. Comparing with the existing Petti and Para made by local blacksmiths, it is found that the pump is cheap as well as efficient.
Open Access
Screening for resistance to aphis craccivora in vegetable cowpea and evaluation of early types
(Department of Olericulture, College of Horticulture, Vellanikkara, 1984) Sulochana, K A; KAU; Peter, K V
Cowpea Vigna unguiculata (L) walp is an important legume grown both in tropics and sub tropics. Eighty three cowpea lines were evaluated for field resistance to Aphis craccivora. All the lines except 10 TVU lines were infested by the aphid before 30 days after sowing. The lines TVU 1889, TVU 408, TVU 2896 and TVU 2962 were completely free from aphid infestation observed on leaves internodes and pods upto 60 days of sowing during the first crop season. The resistance reaction observed during second crop season and under controlled aphid infestation revealed that TVU 1889 was the most promising as far as aphid resistance is concerned. There are considerable variability in the cowpea for different characters and the lines K 1552 and TVU 1892 were the earliest to harvest (52 days). Among the weather parameters average number of rainy days and relative humidity had negative relationship with aphid population. Fifteen selected varieties of vegetable cowpea were grown in two seasons under two fertility levels. There were considerable variability in the vegetable types of cowpea for earliness which is important for the crop to be fitted in a multiple cropping system. The variety K 1552 was the earliest (52.13 days) followed by K 868 (52.43 days). The line IIHR 6-1-B is the most average stable variety with the highest mean (62.35 g) and bi value tending to one (0.96). The varieties K 1552, VS 89 and K 868 were high yielders but had bi value more than one and are suited for high yielding environments. The chemical analysis of pods for monosaccharides to polysaccharides ratio indicated that the yard long bean had the highest ratio followed by K 1552, IIHR 6-1-B and VS 87.

Theses

Browse

Thesis Type

Type

Author

Date

Subject

Search Results