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ThesisItem 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 SThesisItem Open Access Influence of leaders in the development of rural areas(Department Of Agricultural Extension, College Of Agriculture, Vellayani, 1981) Shilaja, S; KAU; Tampi, A MThesisItem Open Access Exchangeable aluminium as an index of liming for the acidic upland soils of Kerala(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1987) Meena, K; KAU; Alice, AbrahamAluminium toxicity is the major factor limiting crop production in the acidic soils and the usual practice of alleviating aluminium toxicity is liming* / The present investigation was carried out to find out the distribution of water s dluhle and exchangeable aluminium in the acidic upland soils of Kerala and to test the suitability of exchangeable aluminium as an index for liming them* It was further programmed to find out the growth, yield and nutrient uptake pattern of two acid sensitive crops namely cowpea and fodder maize in soils under different levels of exchangeable aluminium brought out by the use of different levels of lime* Chemical analysis of eighty soil samples representing the five major upland soil types of Kerala viz* laterlte, alluvial, red loam, sandy and forest a oil have indicated the highest amount of exchangeable aluminium and percentage aluminium saturation in the laterite soils* The soil with 3 high level of exchangeable aluminium and percentage aluminium saturation was selected for conducting a pot culture experiment to test the suitability of using exchangeable aluminium as an index of liming* The exchangeable aluminium content of this soil was maintained at different levels by applying different levels of lime and the performance of these crops in this soil was compared by making biometric observations and by chemically analysing plant and soil samples* From the results of the study it was seen that higher levels of exchangeable aluminium adversely affected the growth, yield and nutrient uptake In cowpea and fodder maize* Maintenance of exchangeable aluminium at 1*26 me/100 g with a corresponding percentage aluminium saturation valua of around 30, by the use of 500 kg lime/ha appeared to be the optimum for maximising the yield of cowpea* But in fodder maize this level of lime was found to be insufficient and complete elimination of aluminium toxicity appeared to be essential for maximising production* Since the critical levels of exchangeable aiuainiua appears to be different for different crop3, it is desirable that lias levels to reduce exchangeable aluminium to such a critical level alono be applied. The results of the present study thus point to the advantage in adopting the exchangeable aluminium level of soil as a better index of liming for various crops grown in the upland acidic soils of Kerala.ThesisItem Open Access Forecasting models for crop yield in cashew (anacahdium occident ale l.)(Department of Statistics, College of Veterinary and Animal Sciences, Mannuthy, 1987) Usha, Menon R; KAU; George, K CThesisItem Open Access Estimation of induced variability in chillies(Department of agricultural botany , College of agriculture Vellayani, Trivandrum., 1985) Lekha Rani, C; KAU; Krishnan Nair, NThe 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.ThesisItem 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 CA 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*ThesisItem Open Access Investigations on intervarietal F2 hybrids in cowpea(Department of Agricultural Botany, College of Horticulture Vellanikkara, Trichur, 1981) Sumathikutty Amma, B; KAU; Narayanan Namboodiri, K MCcwpea (Vlgna ungiculata) Is the major pulse crop cultivated in Kerala where the average yield of pulses in general and Cowpea in particular is very low even under modern agronomic practices* This low productivity is mainly due to the absence of high yielding varieties suited for the different agro-climatic conditions. The varietal requirements in Cowpea, in the state vary because of the highly contrasting system of cultivation and this compels Cowpea breeders to evolve varieties of different combinations of plant, pod and seed characters, This is possible by producing different varieties combining the desirable attributes required for the diverse situations by suitable means. One of the ways by which, this can be achieved is through combination breeding in which desirable genes are pooled frcra different sources* In a previous study conducted in the Department of Agricultural Botany, the 202 genotypes v/ere grouped into 17 distinct clusters. Representing 15 clusters, 15 varieties were chosen for intervarietal hybridisation and their F^'s evaluated during 1979-80, Seeds collected from the plants of the 16 Intervariota] crosses along with their parents were used for the study. Two families In each of the 16 crosses were studied along with their respective parents for the pattern of inheritance of 15 economic characters. Most of the characters were found to be inherited as quantitative characters controlled by either polygenes or by a few major genes with their action being suitably modified by minor genes. The crosses 5 x 15 (g p .p l s . 139 x p .118) and 6 X 8 (Red Seeded Selection X Kolingipayar) were identified as suitable ones for grain - production and also for using as dual purpose Cowpea culture since they might throw segregants best suited to those purposes. For the specialised system of Cot/pea culture practised in summer rice fallows exclusively for vegetable purpose, the crosses 14 X 16 (Pannithodan-early X Kolingipayarwhite), 17 X 16 (Mancheri-black X Kolingipayar^hite) and 10 X 6 (IC. 20729 X Red Seeded Selection) appeared to be the Ideal ones*ThesisItem Open Access Pattern of growth in domestic fowl(Department of Statistics, College of Veterinary,Mannuthy, 1981) Jacob Thomas, M; KAU; Surendran, P UUnder uniform feed formula and identical management practices, 30 Australorp (ALP) males, 26 (ALP) females, 25 white Leghorn(WL) males and 31 (WL) females, were reared for 24 weeks in Kerala Agricultural University Poultry Farm, Mannuthy to study their growth patterns. The initial mean body weights of chicks were 35g. for ALPmales, 34.4615g. for ALP females, 33.04g for WL males, 32.0645g. for WL females. Throughout the experiment males in each genetic group had a higher mean weight than females. A plateau on the body weight was reached by the end of 23 weeks in almost all birds, indicating that 24 weeks completely covered the growth period. By the end of the experiment the mean body weight was 1858g for ALP males, 1488.4615g. for ALP females, 1556.8g. for WL males, 1306.1290g for WL females. Though there was no significant difference between the groups at the end of the fourth week, significant differences between pairs were observed after 16 weeks. Exponential (y =aebx), Gompertz (y = abcx) and Logestic (105/y = a + bcx) curves were found to be suitable for fitting body weights for 24 weeks. The first two gave extremely good fit. Modified exponential was good only for data of twelve weeks. When growth rates for twenty four weeks were compared on the basis of the fitted curves for all birds the conclusion arrived at was the same for exponential and Gompertz curves. The rates of growth for ALP males, WL males, ALP females WL females and were in the descending order of magnitude; they were significantly different. Same was the inference obtained when Rao’s method of comparing rates of growth was adopted. The result obtained for comparing the rates of growth by fitting Exponential and Modified exponential for the body weights of birds for 12 weeks were similar. Both the curves gave very satisfactory fit to the data. The coefficient of correlation between the observed and expected body weights was nearly unity in almost all cases.ThesisItem Open Access Economics of banana cultivation in Trichur district(Department of Agricultural Economics, College of Horticulture, Vellanikkara, 1983) Indira Devi, P; KAU; Mukandan, KThis investigation on economics of banana cultivation in Trichur district was conducted during 1983.The study confined to irrigated nendran banana in Chalakudy block with the following objectives viz. to estimate cost and returns; to evaluate resource use efficiency in production; and to study the problems of banana growers. Ninetyeight holdings were selected by following the stratified two stage random sampling technique and the information was collected using a pretested schedule, through personal interview. The total cost of cultivation (cost C) of banana worked out to Rs.41814.13 per hectare. Of this, the most important item of expenditure was human labour. Average labour requirement for banana cultivation was 702.96 mandays per hectare. This was followed by expenditure on manures, fertilizers, propping materials, suckers and irrigation. All of the farmers in the locality applied chemical fertilizers though not upto the recommened level. Plant protection expenses were only 0.30 per cent of total cost. In the operationwise expenditure, manures and manuring operations demanded highest investment and formed 42.50 per cent of total cost. Propping, planting, after cultivation and irrigation, harvesting and handling and preparatory cultivation in that order were the other operations which needed investment. Plant protection operations accounted for 0.92 per cent of total cost. The average returns from banana cultivation were Rs.65011.90 per hectare. The net income from banana cultivation was Rs.23,197.77 per hectare with a benefit cost ratio of 1.55. On a per plant basis, the average cost of producing a bunch was Rs.14.31 and it gave a return of Rs.26. In the linear production function model fitted, plant population and expenditure on labour were the factors which had significant influence on the dependent variable viz. total returns. The former had a positive influence and for the latter the influence was negative. The same model was fitted for the data converted to a per plant basis. The analysis revealed that the farmers were using labour over and above the optimum level. So its use has to be restricted.
