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Kerala Agricultural University, Thrissur
The history of agricultural education in Kerala can be traced back to the year 1896 when a scheme was evolved in the erstwhile Travancore State to train a few young men in scientific agriculture at the Demonstration Farm, Karamana, Thiruvananthapuram, presently, the Cropping Systems Research Centre under Kerala Agricultural University. Agriculture was introduced as an optional subject in the middle school classes in the State in 1922 when an Agricultural Middle School was started at Aluva, Ernakulam District. The popularity and usefulness of this school led to the starting of similar institutions at Kottarakkara and Konni in 1928 and 1931 respectively.
Agriculture was later introduced as an optional subject for Intermediate Course in 1953. In 1955, the erstwhile Government of Travancore-Cochin started the Agricultural College and Research Institute at Vellayani, Thiruvananthapuram and the College of Veterinary and Animal Sciences at Mannuthy, Thrissur for imparting higher education in agricultural and veterinary sciences, respectively. These institutions were brought under the direct administrative control of the Department of Agriculture and the Department of Animal Husbandry, respectively. With the formation of Kerala State in 1956, these two colleges were affiliated to the University of Kerala. The post-graduate programmes leading to M.Sc. (Ag), M.V.Sc. and Ph.D. degrees were started in 1961, 1962 and 1965 respectively.
On the recommendation of the Second National Education Commission (1964-66) headed by Dr. D.S. Kothari, the then Chairman of the University Grants Commission, one Agricultural University in each State was established. The State Agricultural Universities (SAUs) were established in India as an integral part of the National Agricultural Research System to give the much needed impetus to Agriculture Education and Research in the Country. As a result the Kerala Agricultural University (KAU) was established on 24th February 1971 by virtue of the Act 33 of 1971 and started functioning on 1st February 1972. The Kerala Agricultural University is the 15th in the series of the SAUs.
In accordance with the provisions of KAU Act of 1971, the Agricultural College and Research Institute at Vellayani, and the College of Veterinary and Animal Sciences, Mannuthy, were brought under the Kerala Agricultural University. In addition, twenty one agricultural and animal husbandry research stations were also transferred to the KAU for taking up research and extension programmes on various crops, animals, birds, etc.
During 2011, Kerala Agricultural University was trifurcated into Kerala Veterinary and Animal Sciences University (KVASU), Kerala University of Fisheries and Ocean Studies (KUFOS) and Kerala Agricultural University (KAU).
Now the University has seven colleges (four Agriculture, one Agricultural Engineering, one Forestry, one Co-operation Banking & Management), six RARSs, seven KVKs, 15 Research Stations and 16 Research and Extension Units under the faculties of Agriculture, Agricultural Engineering and Forestry. In addition, one Academy on Climate Change Adaptation and one Institute of Agricultural Technology offering M.Sc. (Integrated) Climate Change Adaptation and Diploma in Agricultural Sciences respectively are also functioning in Kerala Agricultural University.
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ThesisItem Open Access Fungal diseases of selected medicinal plants of Kerala(Department of Plant Pathology, College of Horticulture, Vellanikkara, 1991) Sukumara, Varma A; KAU; ; Abi, CheeranThesisItem Open Access Qualitative changes of yoghurt prepared from milk preserved by different methods(Department of Dairy Science, College of Veterinary and Animal Sciences,Mannuthy, 1990) Prasad, V; KAU; Sukumaran, M VAn experiment was conducted to study the qualitative changes of yoghurt prepared from milk preserved by different methods. An attempt was also made to study the efficiency of LP system in controlling psychrotrops in refrigerated milk thereby extending the keeping quality of such stored milk. The efficacy of the system was compared with pasteurized milk and raw milk stored under similar conditions. An exhaustive review of literature has been presented on the use of various preservation methods employed in milk, quality of yoghurt and other related aspects. The methods of analyses of some important components of milk and yoghurt has been detailed. The milk after collection were divided into three portions and used for various treatments A (raw milk as such), B (laboratory pasteurized) and C )LP activated). Samples in each treatment were again divided into four parts and stored under refrigeration for 0, 24, 48 and 72 hours for further analysis and yoghurt preparation. When raw milk was stored under refrigeration, acidity developed to a significantly high level (P < 0.05) at the end of 72 hours of storage whereas no significant increase in activity was noticed in treatments B and C. This result was corroborated by a decrease in both psychrotrophic and total bacterial counts in milk under treatments B and C. So it was concluded that the development of acidity in treatment A could be due to bultiplication of microbes particularly psychrotrophs. In B and C its growth was arrested by the treatments. Hydrogen peroxide and thiocyanate were detected in all raw milk samples at a level of 3.78 and 7.33 ppm respectively. The level of H2 O2 and SCN – used for the activation of LP system for the study were found to be adequate, since the psychrotrophic count in milk at the end of 72 hours in treatment C was less than that found in treatment B. The residual H2 O2 and SCN – contents at the end of 72 hours were found to be within the normal level found in milk thus having no health hazards, by this method of preservation. When yoghurt samples were prepared from stored milk no significant differences between treatments were noticed in the values of fermentation period, acidity, pH, total proteins and total solids. A significant increase in NPN and tyrosine values were noticed in yoghurt prepared from milk under treatment A indicating extensive proteolysis in milk during storage under this treatment. However, no difference was noticed between treatments B and C. Diacetyl and acetaldehyde were produced at a desirable level in yoghurt samples under all the three treatments. A proper ratio of Str. Thermophiles – 6 and L. bulgaricus – 4 was found to be maintained in all yoghurt samples. On organoleptic evaluation the yoghurt prepared from milk under treatment C could not be distinguished from other two treatments. In fact, yoghurt under C got a higher total score on organoleptic evaluation than A and B. Low score for body and texture, and falvour was observed under treatment A. This may be attributed to the effect of growth of psychrotrophs in raw milk during refrigeration. From the results, it was concluded that good quality yoghurt can be prepared from milk stored under refrigeration following pasteurization or LP activation. Yoghurt samples prepared from milk stored under treatment A was found to be of inferior quality when compared to B and C. The result also confirmed that LP system can be recommended as a safe preservative for extending storage life of refrigerated milk. When such stored milk was used for yoghurt production, no significant difference in the quality was noticed when compared to yoghurt under treatment B. Suggesting that LP activated milk can be conveniently and economically used for the production of fermented milk products like yoghurt without any apparent harmful effect.ThesisItem Open Access Differential adoption of plant protection technology by farmers of Kerala - a critical analysis(Department Of Agricultural Extension, College Of Agriculture, Vellayani, 1995) Meera, B; KAU; Thyagarajan Nair, GIndian agriculture has undergone intensive farming with the introduction of high yielding varieties of crops. Adoption of improved technology and management practices for boosting up production of food grains have resulted in serious pest and disease complexes warranting intensive and extensive use of plant protection chemicals. A number of limitations and adverse side effects such as pest resistance to pesticides, pesticide residues, health hazards, environmental pollution and ecological imbalance have been identified recently. The components of plant protection technology were taken to study the differential adoption in important crops like paddy and vegetables by the farmers and explained the variations in their cognitive, affective and connative components of behaviour with a selected set of independent variables. The study analysed the indigenous practices of plant protection being followed by farmers and also their perception about the impact of pesticides on environmental aspects. The major constraints experienced by the farmers in the adoption of plant protection technology along with the suggestions to overcome the same were also studied. The study was undertaken in two districts of Kerala viz., Thiruvananthapuram and Alappuzha. A sample of 120 farmers each from the two districts was selected and the total sample size for the study was 240.The data were collected using an interview schedule and analysed using suitable statistical techniques. There was significant difference among the farmers of Thiruvananthapuram and Alappuzha districts with regard to their knowledge about chemical and cultural methods of plant protection. Majority of farmers of both the districts belonged to low knowledge group. The farmers of both the districts were ignorant about biological, physical and integrated methods of plant protection methods. Majority of the farmers of both the districts possessed favourable attitude towards chemical method of plant protection. The farmers of Alappuzha district were significantly higher adopters of plant protection methods than the farmers of Thiruvananthapuram district. Majority of the farmers of both the districts belonged to low perception category with regard to their perception about the utility and practicability of plant protection methods. Crops yield index and scientific orientation emerged as significant independent variables in the correlation and multiple regression analysis with regard to the farmers of both the districts. The practices, viz., controlled application of nutrients for reducing pest and disease attack in paddy and use of ‘thulsikeni’ in ‘pandals’ to trap and kill fruit flies in vegetables were judged as the most effective and scientifically rational practices adopted by farmers. The farmer’s perception about the impact of pesticides on environmental aspects was very low and majority of them belonged to low perception category. The constraint ‘untimely supply and high cost of imputs’ was the most important constraint experienced by the farmers of Thiruvananthapuram district, while ‘lack of proper drainage facilities’ was the most serious constraint experienced by the farmers of Alappuzha District. The most important suggestion given by the farmers to overcome the constraints was to ‘develop simple and more compatible plant protection technologies’ and the most important suggestion given by the experts to overcome the constraints experienced by the farmers was to ‘impart adequate training to farmers as well as extension workers on IPM practices’. The strategic model developed by integrating the salient findings of the present study, emphasized the importance of popularizing effective plant protection technology among the farmers in ecologically sensitive rice and vegetable production systems in Kerala.ThesisItem Open Access Nutritional status of women engaged in fishvending in Thivandurm district(Department of Home Science, College of Agriculture, Vellayani, 1993) Karuna, M S; KAU; Prema, LThe study on the “Nutritional status of women engaged in fishvending in Trivandrum District” comprises of the socio-economic and food consumption pattern of the fisherwomen families with special reference to their actual food intake, energy expenditure and nutritional status. Families surveyed were nuclear type belonging to under privileged communities. Main occupation of the families was fishing and fishvending. Most of the families belonged to the income groups of Rs.1000 to 2000. In these families as the income increased the percentage of income spent on food items decreased. Expenditure on education and health was very low. Male members spent much money for their faulty habits like alcoholism and playing cards. Most of the families were in debts and only women were responsible for the economic management of the families. Index developed from various socio-economic variables revealed that all the families lived below the poverty line. All the families were non-vegetarians and fish was the main nonvegetarian food in their diet. However, consumption of vegetables, pulses, eggs and green leafy vegetables was less due to lack of knowledge about nutritious food. Preparation of food is not upto the standard and this results in the poor quality of the food. Unbalanced, monotonous meal pattern was observed in the community. Compared to other stages of life, special attention was given only during infancy and pre-school period. Besides fishvending women were responsible for household tasks and child care practices. The women got employment for 7 months in a year. Most of the women sold the fish either in the markets in the city or by home to home delivery. Income getting from fishvending was not in proportion to the distance covered. Time spent for fishvending activity was more than the time they spent for other activities. Most of the household activities were combined with fishvending activities. It was found that total time spent for fishvending and household activities was more than 10 hours in a day. Time spent for fishvending activities was positively associated with family income, age of the fisherwomen and income of the fisherwomen. Compared to recommended daily allowance, higher energy expenditure was noticed in all the fisherwomen studied. Majority of the women were below the normal weight. Body Mass Index of the women showed that 33.33 percent suffered from energy deficiency. Nutritional status index was developed from height, weight and body mass index. The index developed ranged from 14.04 to 18.58. A highly significant positive association was observed in between nutritional status index of the women and their height, weight, BMI, Index developed from socio-economic factors and their energy expenditure. Clinical examination of the fisherwomen revealed that 95.33 percent of the women were suffering from any one of the nutritional deficiency disorders. Consumption of food quantity and availability of nutrients from the food were not satisfactory. The nutrients like energy, calcium, iron , retinol, thiamine , niacin and riboflavin and Vitamin C were deficient in their diets. As a result nutritional deficiency symptoms were more prevalent among them. Energy expenditure was more than the intake of energy. Blood constituents like haemoglobin, total protein albumin and Vitamin A were deficient in many of the women studied. From the above findings it was concluded that the nutritional status of the fisherwomen was found to be affected by geographic, environmental and disease factors.ThesisItem Open Access Genetic divergence, prepotency and inbreeding depression in para rubber (Hevea brasiliensis Muell. Arg.)(Department of Plant Breeding, College of Agriculture, Vellayani, 1992) Kavitha Mydin, K; KAU; Gopinathan Nair, VA study on genetic divergence, prepotency and inbreeding depression in rubber was undertaken in an effort to identify clones for use as components of polyclonal seed gardens. Forty clones of Indian, Indonesian, Malaysian and Sri Lankan origin were evaluated in a replicated trial at the Rubber Research Institute of India. Genetic variability, correlations and the cause and effect relationships of dry rubber yield and its components were worked out. Genetic divergence was estimated employing the Mahalanobis' D2 techinique. The factors of divergence were identified through principal factor analysis. Twenty promising clones from genetically divergent clusters were subjected to seedling progeny analyses for the estimation of propotency based on performance of their open pollinated seedling progenies and inbreeding depression in the first generation of selfing. Significant clonal variation was revealed in respect of all the physiological, morphological and structural attributes studied as mean values for the fourth year of tapping for the stress period and for the peak yield period. High genetic variability for volume of latex under stress, plugging index under stress, annual mean dry rubber yield and dry rubber yield during the stress and peak periods was indicated by the high estimates of genotypic coefficient of variation. Additive gene effects offering scope for improvement through selection was indicated for dry rubber yield, latex flow rate and volume of latex during the three periods, girth increment rate, annual mean plugging index and plugging index under stress, by the moderate to high heritability estimates along with high genetic advance for these traits. Non- additive gene action was indicated by the high heritability and low genetic advance for dry rubber content during the three periods, girth and bark thickness. At both genotypic and phenotypic levels, annual mean dry rubber yield showed moderate to high positive correlations with dry rubber content and latex flow rate during the three periods, girth, girth increment rate, length of the tapping panel and bark thickness and negative correlations with yield depression under stress and plugging index during the three periods. Dry rubber yield under stress emerged as a more important component than peak dry rubber yield by its higher magnitude of positive direct effect on annual mean dry rubber yield. Latex flow rate during the stress and peak periods and annual mean volume of latex exhibited high positive direct effects on annual mean dry rubber yield while plugging index during the peak yield period, volume of latex under stress and girth increment rate had negative direct effects on annual mean dry rubber yield. The magnitude and direction of the effects of the components on dry rubber yield during the three periods varied indicating these relationships to be under different genetic control. Selection for a high dry rubber yield under stress, annual mean volume of latex and latex flow rate during the stress and peak periods and against a high plugging index during the peak period, volume of latex under stress and girth increment rate would help achieve improvement in annual mean dry rubber yield. Considerable genetic diversity was revealed by the wide range of D2 values and intra and inter cluster distances. The forty clones were grouped into eight genetically divergent clusters irrespective of their country of origin indicating the absence of any relationship between geographical diversity and genetic divergence. Volume of latex, plugging index, latex flow rate, dry rubber content and dry rubber yield contributed more towards divergence than the morphological and structural attributes. Supporting evidence was obtained from principal factor analysis which revealed the yield factor to be the main factor of divergence with respect to the clusters studied. Junveile rubber yield on test tapping, number of latex vessel rows and number of leaf flushes in seedling progenies exhibited high heritability and genetic advance indicating scope for their use as early selection parameters, while girth exhibited high heritability and low genetic advance. These three traits showed significant positive correlations with juvenile rubber yield, of which girth exhibited the strongest association. Juvenile rubber yield, number of latex vessel rows, girth and number of leaf flushes were identified as important traits for being accorded simultaneous emphasis in the computation of performance index and index scores for the determination of recovery of superior seedlings as estimates of prepotency. Nine clones were identified as likely preopotents on the basis of seedling progeny analysis at the age of two years. Selfing resulted in a lower fruit set than open pollination in the clones in general. No significant inbreeding depression was recorded for juvenile vegetative traits and rubber yield in seedlings. Clones PB 28/83, PB 215, RRII 105, AVT 73, PB 217, PB 252, Ch 26, PB 242 and PB 5/51 were identified as likely prepotents from three genetically divergent clusters. They recorded superiority for yield and various yield components. These clones exhibited synchrony in flowering and are suggested as components of a nine parent polyclonal seed garden. For a seven parent seed garden the clones suggested to be excluded are PB 5/51 and PB 242. A polyclonal seed garden comprising these nine or seven clones as components could generate good quality polycross seed material. Appropriate seed garden layouts have been suggested.ThesisItem Open Access Development and application of a scale to measure the efficiency of adult education centres(Department Of Agricultural Extension, College Of Agriculture, Vellayani, 1990) Padmanabhan, V B; KAU; Thampi, A MThis study on the development and application of a scale to measure the efficiency of Adult Education Centres (AECs) was designed to develop and standardize a scale to measure the efficiency of AECs, to evaluate the selected AECs by using the scale developed and to suggest a model for the efficient functioning of AECs. The study was conducted in the Rural Functional Literacy Programme (RFLP) centres of the Rural Development Blocks of Ollukkara and Kodakara in Thrissur district during 1989. A three stage sampling design was adopted for the study. Instructors and learners of the AECs were the two types of respondents included in the study. Efficiency of AEC (dependent variable) and selected 41 factors (independent variables) were the variables for the study. The data were collected from the instructors by using questionnaires and from the learners by using interview schedules. The collected data were analysed using appropriate statistical techniques including percentage analysis, simple, linear correlation analysis, multiple linear regression analysis, step-wise regression analysis and path coefficient analysis. The salient findings oDepartment of Agricultural Extension College of Agriculturef the study are as follows : 1. Thirty seven independent variables out of the 41 were found to have significant positive relationship with the efficiency of AEC. Job commitment of instructor had the highest value of correlation coefficient. 2. The selected 24 independent variables taken together accounted for 98.35 per cent variation in the efficiency of AEC. The nine variables which were found to exert significant influence on the efficiency of AEC when taken together accounted for 96.27 per cent variation in the efficiency of AEC. 3. The best prediction equation was with eight variables which accounted for 93.97 per cent variation in the efficiency of AEC. These variables were instructor-learner communication, information processing behaviour of instructor, job commitment of instructor, job satisfaction of instructor, human resources, supply of inputs, monitoring and empathy of learner. 4. Job commitment of instructor alone explained 89.03 per cent variation in the efficiency of AEC. 5. Job commitment of instructor had the largest direct effect on the efficiency of AEC and its three components, namely, achievements of learners in literacy, awareness and functionality. The high positive correlations of all the other factors with the efficiency of AEC and its components were due to their positive inter-relationship with job commitment of instructor. 6. The scale developed to measure the efficiency of AECs was found to have high validity (content, criterion – related and concurrent) and reliability (test-rest and split-half). 7. The distribution of scores obtained on evaluating the selected AECs by using the scale was found to be normal. 8. A model was suggested for the efficient functioning of AECs based on the results of this study.ThesisItem Open Access Managerial efficiency of cassava farmers(Department Of Agricultural Extension, College Of Agriculture, Vellayani, 1991) Asnantharaman, M; KAU; Thyagarajan Nair, GThe study aimed at analyzing the managerial efficiency of cassava farmers. It was conducted in four districts namely, Thiruvananthapuram (low productivity), and Pathanamthitta (high productivity) in Kerala State and Kanyakumari (low productivity) and Selem (high productivity) in Tamil Nadu state. The first three districts were considered as non- industrial district and Selem district was considered as industrial district also. A total of 240 cassava farmers were selected, 60 from each district following stratified random sampling. The managerial efficiency was measured with the help of a scale consisting of 30 items developed for the study. The data on the managerial efficiency of farmers and on the fifteen socio- psychological and situational factors of the farmers were collected using an interview schedule. The components of managerial efficiency identified empirically were ‘planning’, ‘labour management’, ‘information management’, ‘financial management’ ‘production management (variety)’, ‘production management (practices)’ and ‘marketing management’. The managerial efficiency of cassava farmers as the whole was somewhat better as little more than half of the farmers had high managerial efficiency. While the farmers exhibited high efficiency in the managerial components namely, ‘planning’, ‘labour management’, ‘financial management’ and marketing management’, they were not efficient in the components of ‘Information management’, ‘production management (variety)’ and ‘production management (practices)’. The farmers of industrial district were found to have significantly higher efficiency in the overall managerial efficiency as well as in the managerial components viz., ‘planning’, ‘information management’, ‘financial management’, ‘production management (variety)’, and ‘production management (practices)’ when compared to farmers of non- industrial district. The component- wise performance of farmers on the whole was in the order of ‘labour management’, ‘marketing management’, ‘planning’, ‘financial management’, ‘production management (practices)’, ‘information management’, and ‘production management (variety)’. While farmers of industrial district relatively performed well in ‘production management (variety)’, ‘production management (practices)’ and ‘planning’ when compared to other components, non-industrial district farmers performance was good at ‘labour management’, ‘marketing management’ and ‘financial management’. The managerial components namely, ‘planning’, ‘information management’ and ‘financial management’ were found to be relatively more important than other components with regard to their contribution towards the profit from cassava cultivation. The socio-psychological and situational factors namely, closeness with agricultural support system, market perception, achievement motivation, economic motivation, attitude towards scientific management in crop enterprise, knowledge on scientific management in crop enterprise, cultivated holding, cassava area and irrigation potential were found to be significantly contributing to the managerial efficiency. The major managerial constraints faced by the farmers were lack of awareness, knowledge, conviction, timely information and planting materials; limited resources, uncertainty and shortage of labourers.ThesisItem Open Access Genetic analysis of biological nitrogen fixation traits and yield components in cowpea (Vigna unguiculata (Linn). walp)(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1995) Sreekumar, K; KAU; Manikantan Nair, PA study on the parameters of variability, correlations, path-coefficients, combining ability, gene action and heterosis in cowpea was undertaken at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 1991 to 1993. Fifty three genotypes of cowpea collected from different sources were planted in a field experiment for the estimation of variability, correlation and path coefficient. Eleven biological nitrogen fixation characters, viz., number of days to flower, length of primary root, number of secondary roots, number of nodules in the primary root, number of nodules in the secondary roots, total number of nodules, weight of effective nodules in the primary root, weight of nodules in the secondary roots, total weight of nodules, nitrogen content in the plant at 50 per cent flowering and plant dry weight and six yield characters, viz., grain yield per plant, length of pods, number of pods per plant, number of seeds per pod, weight of 100 seeds and seed protein content were considered for this study. The ten selected varieties/types from the initial evaluation trial were crossed in a line x tester model, keeping the three high nitrogen fixing types and three high yielding types as lines (total six lines) and two low nitrogen fixing and two low yielding types as testers (total four testers). The F1’s along with their parents were compared in a field experiment and combining ability, gene action and heterosis were estimated. The study of combining ability and gene action were confined to six biological nitrogen fixation characters, viz., number of days to 50 per cent flowering, weight of nodules in the primary root, total weight of nodules, weight of effective nodules, dry weight of the plant and nitrogen content per plant and six yield characters, viz., length of pod, number of seeds per pod, number of pods per plant, hundred seed weight, seed protein content and grain yield per plant. The analysis of variance revealed that a considerable amount of variation among the varieties was present with respect to the characters under study. Characters like number of days to flower, total nodule weight, nitrogen content per plant, weight of 100 seeds and seed protein content had recorded narrow relative magnitude of difference of phenotypic and genotypic coefficient of variation along with high heritability estimate. Moderate magnitude of difference of PCV and GCV along with moderate heritability was recorded for the characters viz., number of nodules in the primary root, number of nodules in the secondary roots, total number of nodules, weight of effective nodules in the primary root, weight nodules in the secondary root, length of pods and number of pods per plant. Plant dry weight and grain yield registered a wider difference of PCV and GCV along with low heritability indication the greater influence of environment over these two characters. Genetic advance as percentage of mean was found to be high for the characters like number of nodules in the secondary roots, weight of effective nodules in the primary root, weight of nodules in the secondary roots, total nodule weight, number of pods per plant and 100 seed weight and moderate for number of nodules in the primary root, total number of nodules and grain yield. Low genetic advance was recorded by number of days to flower, plant dry weight, nitrogen content per plant, length of pod and seed protein content. Hence characters such as number and weight of nodules in the primary root, number and weight of nodules in the secondary roots, total number and weight of nodules, number of pods per plant and weight of 100 seeds may be controlled by additive genes whereas days to 50 per cent flowering, nitrogen content in plant, length of pod and seed protein content may be controlled by non-additive genes. Correlation coefficients were workedout at the genotypic and phenotypic levels. Based on the genetic correlation of characters studied, it was understood that high nitrogen fixing genotypes may not be high yielders because of the antagonistic relationship between grain yield and total nitrogen per plant. Weight of nodules in the primary root and total nodule weight were positively correlated with the nitrogen content in plant. Hence genotypes which was able to form effective large nodules on the primary root system seems to be a better nitrogen fixer. Number of days to 50 per cent flowering had negative genotypic correlation with grain yield. Hence an early flowering genotype may be better yielder than a late flowering type. Weight of hundred seeds and seed protein content exhibited very strong negative correlation indicating that small seeded genotypes may be better with respect to protein content. Grain yield recorded positive phenotypic and genotypic correlation with number of pods per plant. Path coefficient analysis at the genotypic level revealed that total number of nodules had the highest positive direct effect on nitrogen content per plant followed by weight of effective nodules in the primary root and weight of effective nodules in the secondary root. Highest positive direct effect was recorded for length of pod with grain yield. The combining ability analysis revealed that both additive and non-additive gene actions were important for all the characters under study. However GCA and SCA variance ratio which was less than unity for all the traits under study indicated the predominance of non-additive gene action in the inheritance of these traits. Considering the combining ability effects, VCP 4 was found to be the best general combiner for most of the biological nitrogen fixing characters and V 322 was the best general combiner for the grain yield. The cross combination of V 27 x C 152 and V 271 x Co Vu 85020 showed the best performance with respect to sea for the character number of days to 50 per cent flowering while VCP 4 x C 152 for weight of nodules in the primary root and nitrogen content in plant. DPLC 210 x PTB 2 recorded high sea for total weight of nodules, weight of effective nodules, dry weight of the plant and number of pods per plant, on the other hand Co Vu 358 x C 190 recorded high sca for length of pod, number of seeds per pod and seed protein content. The cross combination V 322 x C 190 exhibited high sca for hundred seed weight and V 27 X C 152 for grain yield per plant. Marked heterosis was observed in many cross combinations for most of the characters studied and pronounced heterotic expression was obtained for weight of nodules in the primary root, total weight of nodules, weight of effective nodules, dry weight of the plant at 50 per cent flowering, number of pods per plant and grain yield. It was already established that these characters are predominantly governed by the non – additive gene action. Hence the heterotic vigour expressed by the hybrid combination with respect to these characters are justified. Since the biological feasibility for the exploitation of heterosis is not economical as a plant improvement programme in this crop, genetic improvement of these trait can be brought about more effectively through combination breeding involving genetically diverse and high combining parants.ThesisItem Open Access Incorporation of resistance to fruit cracking in a bacterial wilt resistant genetic background in tomato(Department of Olericulture, College of Horticulture, Vellanikkara, 1995) Sadhan Kumar, P G; KAU; Rajan, SAn investigation on “Incorporation of resistance to fruit cracking in a bacterial wilt resistant genetic background in tomato” was undertaken in the Department of Olericulture, College of Horticulture, Vellanikkara during the period from January, 1991 to March, 1994. The findings are succinctly mentioned below. Evaluation for bacterial wilt resistance revealed that Sakthi and LE 79 – 5 are consistently resistant to bacterial wilt. Four addition sources of bacterial wilt resistance were identified viz., LE 214, CAV – 5, LE 415 and LE 382 – 1. Resistances to bacterial wilt in these lines was governed by recessive genes. Screening for resistances to fruit cracking resulted in the identification of fifteen tomato genotypes which were found to be resistant to both radial and concentric cracking. Resistances to concentric fruit cracking in these lines were found to be dominant. All the bacterial wilt resistant genotypes had a higher content of total phenols, O.D. phenol and ascorbic acid than the susceptible line pusa Ruby. The crack resistant varieties had a higher content of insoluble solids and pectin, lower content of acidity, total sugar and reducing sugar in fruits, thick fruit skin and pericarb as compared to susceptible variety. The elasticity of skin was also higher in crack resistant genotypes. Crack resistant varieties had a compact arrangement of parenchymatous cells when compared with crack susceptible variety. The resistant lines had a thicker cuticle also. The F1 S developed by line x tester crossing were susceptible to bacterial wilt. All the same, they were resistant to both radial and concentric fruit cracking indicating dominant gene action for crack resistance. The F2 segregants with combined resistance to both bacterial wilt and fruit cracking were selected for further improvement.
