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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 Survival of Xanthomonas campestris pv. Oryzae and its Control in Kuttanad(Department of Plant Pathology, College of Agriculture, Vellayani, 1996) Mary, C A; KAU; Sasikumar NairThe present investigation was taken up to understand the factors responsible for the recurrence of bacterial blight disease in a severe from only during the additional crop season in Kuttanad. The mode of survival of the pathogen during and in between the two major cropping seasons of Kuttanad region were also studied in detail. An extensive survey was also conducted among 115 farmers in 12 Krishibhavans of Kuttanad taluk for this purpose to collect specific informations on existing cultural practices, crop variety, nature and distribution of weed flora and self sown rice plants in and around rice fields and on wether data from June 1992 to March 1994. The efficacy of two different methods of spraying, prophylactic and curative using streptocycline, mixture of streptomycin and oxytetracycline in the proportion 1:9, Bactrinol – 100 cowdung extract on the control of bacterial blight disease was tested under field condition at Nedumudi in Kuttanad. The survey showed that there was considerable variation in the incidence of bacterial blight in Kuttanad taluk. Among the 12 Krishibhavan areas the disease incidence was maximum in Ramankari and Nedumudi and minimum in Kavalam, Kainakary and Muttar. In Neelamperoor and Thalavadi areas there was no incidence of this disease during the period of survey. Between the two major cropping seasons the disease incidence was more during the additional crop season than during Punja season. Red Triveni and Jyothy were the most popular varieties cultivated in the area and more than 50% of the farmers cultivate Red Triveni. It was observed that the variety Red Triveni as highly susceptible to bacterial blight disease. The isolate of the pathogen Xanthomonas oryzae pv. Oryzae from the rice variety Red Triveni was capable of both gelatin liquefaction and starch hydrolysis. The pathogen X. oryzae pv. oryzae was found to survive for a maximum period of 42 days in infected seed, 105 days in infected straw, 56 days in infected stubbles at room temperature, 24 days in infected stubbles under dry land condition and 14 days under wet land condition. The pathogen did not survive in soil and water. Weeds like Oryza sativa var. fatua and Paspalum conjugatum served as alternate host for the pathogen. Bacterial blight infected self sown rice plants could be seen in Kuttanad during the cropping and non cropping seasons. Due to certain specific reasons, the cultivation practices were often found to extend beyond the normal cropping seasons in the region resulting in the chances of survival of bacterial blight pathogen in the host plant itself. The specific weather conditions during the additional crop season played an important role for the severity of bacterial blight desease in this season in Kuttanad. The pathogen X. oryzae pv. oryzae was tested for sensitivity to antibiotics, Bactrinol – 100 and cowding extract under in vitro conditions. The maximum growth inhibition was obtained with oxytetracycline followed by chloramphen icol which was statistically on par with oxytetracycline. The effect of increasing concentrations of oxytetracycline in combination with streptomycin on growth of X. oryzae pv. oryzae was studied with 100, 250 and 500 ppm concentrations. The growth inhibition increased not only with the concentrations of antibiotic from 100–500 ppm but also with increasing concentration of oxytetracycline. The maximum zone of growth inhibition was obtained with 1:9 proportion of streptomycin and oxytetracycline. The five treatments selected for field evaluation trial included streptocycline at 500 ppm, streptomycin + oxytetracycline (1:9) at 250 ppm and 500 ppm, Bactrinol -100 at 500 ppm and fresh cowdung extract at 20g/1. Two different spraying methods, prophylactic and curative were evaluated in two rice varieties, T(N) 1 and jyothy. The reduction in disease index by prophylactic and curative sprayings was maximum after spraying with cowdung extract 20g/1. As regards to two methods of spraying, significant reduction in per cent disease index was obtained with curative spraying. The maximum per cent increase in grain yield over control was obtained after curative spraying with 500 ppm streptomycin and oxytetracycline mixture in jyothy followed by cowdung extract 20 g/l. In T(N) 1 and jyothy both by prophylactic and curative spraying, the thousand grain weight was maximum with cowdung extract 20 g/1. As regards to two method of spraying, significant increase in grain yield and thousand grain weight was obtained after curative spraying. In T(N) 1, both by prophylactic and curative spraying the per cent increase in straw yield was maximum with a mixture of streptomycin and oxytetracycline at 500 ppm and jyothy with cowdung extract 20g/1. In T(N)1 significant reduction in chaff per cent was recorded by prophylactic spraying while in Jyothy no significant difference was obtained by the two methods of spraying. In both these varieties the reduction in chaff per cent was maximum by spraying with cowdung extract (20g/1). It was observed that two prophylactic spraying with selected bactericidal agents, neither resulted in any significant reduction in disease index nor increase in yield as compared to curative spraying. This could be due to the fact that in Kuttanad bacterial blight disease usually occurred only around the panicle initiation stage or even later. Therefore a need based curative spraying schedule would be most effective for the control of bacterial blight disease in Kuttanad. On working out the economic benefits of controlling bacterial blight it was observed that there will be economic return only from spraying infected plants of both (T(N) 1 and jyothy with cowdung extract 20g/1. The return from plants sprayed with all other treatments in the investigation was low when compared to unsprayed control plants. Thus it will be economically advantageous to use cowdung extract to control bacterial blight of rice.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 Effectiveness of soil solarization for the control of soft rot disease in ginger(Department of Plant Pathology, College of Horticulture, Vellanikkara, 1996) Vilasini, T N; KAU; Peethambran, C KThe effectiveness of soil solarisation for the control of soft rot disease in ginger was studied at the College of Horticulture, Vellanikkara, Thrissur during March 1992 to December 1993. The beds were inoculated with Pythium aphanidermatum, five days before the solarisation. Transparent, 150 guage polyethylene sheets were used for solarizing the beds. Maximum soil temperatures recorded were 63.00, 59.00 and 46.50 at 5, 10 and 15 cm depths in solarized soil, while, that in non-solarized soils were 49.50, 43.00 and 40.00C, respectively, at 5,10 and 15 cm depths. Temperature in the solarized soil at 5 cm depth was above 50.00 C for the entire solarisation period and above 55.00 C for 38 days, while, at 10 cm depth the temperature was above 50.00 C for 35 days and above 55.00 for five days. The soil temperature at 15 cm depth never reached 50.00 C during the solarisation period. Based on the soil and air temperature recorded, two simple regression equations at 5 and 10 cm depths, one simple equation at 15 cm depth and one multiple regression equation at 10 cm depth were developed for predicting soil temperature under polyethylene mulch. Rate of germination in ginger was enhanced by solarisation. Significant effect of solarisation was observed in controlling the pre and post-emergence rotting in ginger. Increasing the period of solarisation from 30 to 45 days did not result in a corresponding reduction in the pre-emergence rotting. Trichoderma incorporated neem cake amended 30 day solarized treatment was highly effective and recorded cent percent control of the soft rot disease, while, maximum disease incidence (90.67%) was in Trichoderma incorporated neem leaves amended 45 days solarized plots. Reduction in Pythium population ranging from 79.49 to 99.1 per cent was observed in solarized plots immediately after the removal of polyethylene sheets. Solarization reduced the total fungal, bacterial, actinomycetal and Pseudomonas sp. population in the field. Plants grown in solarized plots showed better colonization of VAM and Azospirillum. Significant reduction in the nematode population was recorded by solarisation. Solarization had a profound suppressive effect on the weed population and it lasted till harvest. Solarization effect was more pronounced in dicots. Eventhough, solarisation substantially reduced weed population, its effect was less in the edges. Bulbostylis barbata, Cynodon dactylon and Cyperus rotundus survived the solarisation effect. Increased growth response of ginger plants was observed as a result of solarization. Growth parameters like height, number of leaves/plant, number of tillers, number of roots, leaf length, leaf breadth, fresh weight of shoots and rhizomes were influenced by solarisation. Significant increase in the yield was obtained through solarisation. Trichoderma incorporated and neem cake amended 30 days solarized treatment gave the maximum yield/plant (623.23 g) and also per plot yield (10159.57 g), which was 5361 per cent more than that of control. Availability of nitrogen, phosphorus and potassium was improved by solarisation. The initial cost of solarization is comparatively high, an amount of Rs. 52,500/- is required for solarizing one hectare of ginger field. An additional profit generated from this technique was Rs. 40,136/ha for 30 days solarisation.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.ThesisItem Open Access Characterisation and evaluation of the dwarf cattle of Kerala(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1994) Girija, C R; KAU; Sosamma, IypeThe native cattle of Kerala have been treated as non descript animals always eventhough they possess some special features. The dwarf cattle often called as Vechur were very popular in Central Travancore until 35 years back. With the emergence of the crossbred population of cattle the traditionally reared local cattle have gradually suffered genetic erosion. Under this circumstance, the present work was undertaken to characterize and evaluate the germplasm of local dwarf cattle of Kerala by studying (a) the karyotype and morphology of chromosomes using G-banding (b) the population structure by means of gene frequencies of different blood proteins (c) the growth and production performance. The characterization and the evaluation would help in finding out the genetic differences of the dwarf cattle which will help in deciding about the conservation of their germplasm as a reserve for the future. The dwarf cattle maintained under the ICAR scheme on “Conservation of germplasm of Vechur cattle of the coastal area and the dwarf cattle of the high ranges of Kerala” formed the material for the study. The characterization and evaluation was carried out through the cytogenetic, immunogenetic and polymorphism studies as well as through the description of the growth and production traits. Karyotype analysis was carried out using peripheral blood leukocyte culture technique described by Halnan (1977) and Halnan (1989) with suitable modifications. G-banding of chromosomes were done by the method described by Thiagarajan (1993). Blood protein polymorphism systems such as Haemoglobin and transferring were studied by poly acrylamide gel electrophoresis in horizontal dimension. (Gahne et. al. 1977) with suitable modifications. The statistical analysis of the growth and production data were done as suggested by Snedecor and cochran (1967). The diploid chromosome number of the dwarf cattle was found to be 60, with 29 pairs of autosomes and one pair of sex chromosomes. All the autosomes and the ‘Y’ chrosome were acrocentric. The X chromosome was submetacentric. The relative length of the autosomes ranged from 1.757 to 5.431 per cent. The relative length of the X and Y chromosomes were found to be 5.591 per cent and 2.875 per cent respectively. In the karyological array, the X chromosome occupied the first position. The X chromosome was biarmed and the arm ratio and centromere index obtained were 2.182 and 0.314 respectively. The karyotype and morphometric measurements resembled the finding in Bos indicus group of cattle. The G-banding pattern of chromosomes revealed 72 regions and 314 G-bands. The Y chromosome had 7 G-bands in the ‘q’ arm which resembled the ‘q’ arm of Bos taurus described in the international system for cytogenetic nomenclature of domestic animals. There were two haemoglobin variants HbA and HbB and three phenotypes viz. HbAA, ,HbAB and HbBB , in the population. The heterozygocity was found to be 0.4815. The population was found to be in genetic equilibrium with respect to the Haemoglobin locus. Six transferring phenotypes controlled by three alleles TfA, TfD and TfE were observed. The frequency of TfE (0.359) allele in the dwarf cattle was as high as the frequency of the allele reported in the zebu cattle. The absence of transferring variants like TfF, TfH, TfN and TfG and higher frequency of TfE allele are probably indicative of the genetic isolation of the population from exotic breeds. The absence of TfB and TfF allele which is present in Gir, Hariana, Kankrej, Kangayam, Ongole, Red Sindhi, Sahiwal and Tharparkar also indicates that the dwarf cattle has not inherited genes from the above cattle breeds. The body weights and measurements of calves at birth studied showed that the male calves had a higher body weight (12.55 ± 0.31 kg with a CV of 7.86 per cent) than female calves (10.78 ± 0.40 kg with a CV of 15.02 per cent). The same trend was observed with regard to the birth body measurements also. The heart girth measurement and body weight showed a positive correlation from birth to the 24th fortnight. There is a 100 per cent increase in the birth weight by the 5th fortnight and a three-fold increase by the 10th fortnight. The average daily gain in weight for the four periods I e., fortnights 0-6, 7-12, 13-18 and 19-24 were 0.160 ± 0.011, 0.167 ± 0.018, 0.212 ± 0.011 and 0.139 ± 0.015 respectively for female calves and 0.188 ± 0.023, 0.145 ± 0.016, 0.116 ± 0.025, 0.242 ± 0.049 kg respectively in male calves. During the period from birth to 6th fortnight the growth rates in males and females were similar. The gain in body weight per day during the periods from 7 to 12th and 13 to 18th fortnight was comparatively less for males but the trend reversed during the period of fortnights for 19 to 24th. The average body weights of adult females and males were 126.90 ± 3.56 kg (CV 16.39%) and 210 ± 15.75 kg (CV 14.95%) respectively. The body measurements such as length, heart girth and height (in cms) in females were 97.5 ± 1.12 (CV 5.85%), 115.60 ± 1.32 (CV 5.82%) and 87.53 ± 0.82 (CV 4.82%) respectively. The corresponding figures in males were 111.5 ± 3.77 (CV 6.76%), 146.0 ± 2.92 (CV 3.99%) and 107.5 ± 1.35 (CV 2.50%) respectively. The average body weights and measurements were lesser than those reported in other Indian breeds and crossbred cattle. The total lactation milk production performance of the dwarf cattle was 471.68 ± 38.72 kg (CV 45.29%) in an average lactation length of 217 ± 16.50 days (CV 32.20%). The average daily yield was 2.17 ± 0.11 kg (CV 29.48%). The dwarf cattle attained a peak yield of 3.71 ± 0.16 kg (CV 21.5%) in 23.23 ± 1.703 days (CV 37.38%). The milk production performance eventhough was lesser than crossbreds or some recognized Indian breeds, the milk production in comparison with the body size was reasonable. Considering the morphology of the Y chromosome, the Hb as well as Tf polymorphism and their allelic frequencies, it is to be summarized that the stock of dwarf cattle of Kerala maintained at Kerala Agricultural University is genetically isolated from the other cattle breeds of the country and world. The body size and milk production of the cow indicates its suitability for a farmer who requires milk just for home consumption. The study strongly confirms the necessity of conservation of the dwarf cattle of Kerala which is the smallest variety available in India and perhaps in the world itself.ThesisItem Open Access Performance of selected orchids under varying light regimes, culture methods and nutrition(Department of Horticulture, College of Agriculture, Vellayani, 1996) Sabina George, Thekkayam; KAU; Mohanakumaran, NThe present study was undertaken to evolve agrotechniques for cut flower orchid production in Kerala. Two experiments were conducted at the College of Agriculture, Vellayani in 1991 and 1992 with two popular cut flower varieties namely Arachnis Maggie Oei ‘Red Ribbon’ and Dendrobium Sonia – 16. The effects of varying light intensities and nutrient regimes under two methods of cultivation were assessed in Arachnis Maggie Oei ‘Red Ribbon’ (Experiment 1) and in Dendrobium Sonia -16, the performance under varying light intensities and nutrient regimes was evaluated (Experiment 2) In Arachnis Maggie Oei ‘Red Ribbon’, trench culture was found to promote growth, flowering and the floral attributes. The number of leaves, aerial roots, leaf area and plant height were greater in the trench grown plants. The number of inflorescences produced, their branching, length and vase life were also enhanced under trench culture. The effect of light intensities on growth was mediated through interactions with culture methods and nutrients. The trench grown plants under 50 and 75 percent light had a greater number of leaves and leaf area. The plants receiving 500 ppm of P and K under 100 percent light had a shorter stature. The direct effect and interactions of nutrients on growth were observed at certain months during the experimental period which was indicative of differences in the requirement at different stages of growth. The dry matter content of the stem and apical shoot was greater in the plants receiving 500 ppm P. Inflorescence production and the vase life of inflorescences was greater under 100 and 75 percent light. Branching of inflorescences was greater under 75 percent light. In Dendrobium Sonia -16 the number of inflorescences produced was greatest under 75 percent light. The length of the inflorescences was greater under 75 percent light and the span area of the flowers was greater under 50 and 75 percent light. Nitrogen at 500 ppm increased the length of the inflorescences, the number of flowers in an inflorescence, and the span area of the flowers. The number of inflorescences produced was also greater in the plants receiving 400 or 500 ppm N, 400 or 500 ppm K and in those receiving 500 ppm P. Interactions between the nutrients and between light intensities and the nutrients were also observed. The nutrient composition of the leaves in both the cultivars were enhanced by the 400 and 500 ppm doses of N and P and 500ppm K. Based on the observed effects, in Arachnis Maggie Oei ‘Red Ribbon’, trench culture of plants under 75 to 100 percent light and a nutrient dosage of 300 ppm N, 400 ppm P and 300 ppm K from planting till nine MAP and thereafter a dosage of 400 to 500 ppm N, 400ppm, P and 500 ppm K can be recommended. In Dendrobium Sonia -16 growing in pots under 75 percent light with 400 to 500 ppm of N, P and K can be recommendedThesisItem Open Access Somaclonal variation in black pepper (piper nigrum L)(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1996) Shylaja, M R; KAU; Sreekandan Nair, GInvestigations on the exploitation of somaclonal variation for screening for resistance to Phytophthora foot rot disease in black pepper were carried out at the Plant Tissue Culture Laboratory of the Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara during September 1991 to January 1995. Calliclones of different black pepper cultivars viz. Kalluvally, Cheriakanyakkadan, Balankotta, Karimunda and Panniyur – 1 were produced with and without applying in vitro selection pressure using toxic metabolite(s) of Phytophthora capsici. In vitro induction of mutation using gamma irradiation and partial purification of the toxic metabolite(s) present in the culture filtrate of P. capsici were also attempted in the present study. Leaf puncture bioassay of the concentrated culture filtrate (CCF) of P. capsici showed that toxic metabolite(s) were accumulated in the culture filtrate. The symptoms produced by CCF were quite typical of natural and artificial infection by P. capsici. Concentrated culture filtrate induced quick electrolyte leakage from leaves and calluses. Concentrated culture filtrate induced necrosis on susceptible calli. The cultivars showed significant variation in callus necrosis. Prolonged duration of selection/screening with CCF totally inhibited the regeneration potential of the calli. Concentrated culture filtrate was not found to inhibit shoot proliferation and shoot growth in already regenerated cultures but inhibited the root growth. In the three direct selection/screening methods tried for calli viz. growing in CCF incorporated MS medium (Method 1) shaking in CCF incorporated liquid MS medium (Method 2) and double layer culture technique (Method 3), cultivars showed significant differences in callus necrosis and callus growth. Direct screening of calli was not found to inhibit the regeneration of shoots, shoot proliferation and recovery of rootable shoots but affected the root growth adversely. Gamma irradiation of calli using 60Co source did not give any better response to in vitro screening. The toxic metabolite(s) present in the culture filtrate could not be separated by organic solvent fractionation. However ion exchangers like Dowex 1 and Dowex 50 could be used for separation of the toxic fraction from the filtrate. The response of five different cultivars at various stages of development of cultures when compared, it was found that the cultivars differed significantly in callusing, callus growth, regeneration of shoots, recovery of rootable shoots and root growth. The clones regenerated from screened and unscreened calli were further tested for resistance/ tolerance to P. capsici using different methods of screening viz.natural screening (keeping in infected field), screening by electrolyte leakage method and screening by artificial inoculation of culture disc of P. capsici. None of the regenerated calliclones were found to be resistant to the disease in natural screening. When the tolerance level of the regenerated calliclones was looked into, the performance of the unscreened calli derived clones was found better as compared to the screened calli derived ones. The calliclones of different cultivars differed significantly inthetolerance/susceptibility reaction to the disease. The calliclones of Cheriakanyakkadan recorded greater degree of tolerance to the disease when compared to others. Among the cultivars studied, Kalluvally exhibited high rate of somaclonal variation.ThesisItem Open Access Ecophysiology and management of Isachne in rice fields of Onattukara(Department of Agronomy, College of Horticulture, Vellanikkara, 1996) Abraham, Varughese; KAU; Tajuddin, EIsachne miliacea Roth is the most dominant weed in the 28,000 ha of low land rice fields of the coastal sandy Onattukara region, situated in Kollam and Alapuzha districts of Kerala. A serious of investigations were undertaken at Rice Research Station, Kayamkulam, during 1991 to 1994 with the objective to identify the major weeds in the rice ecosystem and to bring out the ecophysiology of 1. Miliacea and to find out a suitable weed management strategy for the rice based cropping system of Onattukara. Isachne miliacea was found to be the dominant weed in rice during Kharif and Rabi seasons. The weed seeds germinate in April – May, attains its peak vegetative growth in July and flowers in October. The seeds mature in November and the plants dry off in January with the onset of summer. The weed is propagated by seeds and stem cuttings. Germination of seeds can be prevented by submerging the seeds in the area in water even to a depth of one centimetre. The forcing of the stem cuttings of 1. Miliacea to a depth of five centimetre below the soil surface or maintaining a submergence for more than five centimetre can effectively check the vegetative multiplication of the weed. Seeds attained physiological maturity in November and remained dormant upto March. Seeds of the season that remain on the surface germinate fully in April – May with the pre – monsoon showers while the buried seeds remain dormant. Burying the seeds to more than five centimetre depth and water stagnation in July to November induced secondary dormancy. Viability of the seeds was lost faster at shallow depth of burial. Crop weed competition studies were conducted in Kharif and Rabi for two years with different densities of 1. Miliacea. Weed competition was severe in dry dibbled Kharif compared to wet transplanted Rabi. Even a small density of five 1. Miliacea plants per square metre produced appreciable biomass and reduced the DMP of rice substantially. Integrated weed management study was conducted in Kharif and Rabi for two years in a split – plot design in three randomised blocks. Kharif season treatments formed the main plots for Rabi trial. In Kharif five pre – emergence herbicides were compared with local practice. Local practice of hoeing on 15 DAS and HW twice on 25 and 40 DAS gave maximum grain yield. Application of oxyfluorfen 0.1 kg ha-1 followed by HW on 30 DAS was on par with local practice and ranked second. The performance of other herbicides anilofos 0.40 kg, butachlor 1.25 kg and thiobencarb 1.25 kg per hectare were also satisfactory when followed by one HW on 30 DAS. Pretilachlor 0.50 kg ha-1 was phytotoxic to rice. The tested herbicides effectively controlled 1. miliacea upto harvest of rice compared to local practice. During Rabi the effect of pre-plant spray of glyphosate and hand weedings were compared. Among the treatments a pre – plant spray of glyphosate after harvest of Kharif controlled 1. miliacea best and gave maximum rice yield in Rabi season. Kharif treatments did not show any significant influence on yield of rice during Rabi. From the study it could be concluded that pre – emergence spray of oxyfluorfen 0.1 kg ha-1 followed by one HW on DAS in Kharif and pre – plant application of glyphosate 0.75 kg ha-1 on residual weeds immediately after the harvest of the Kharif crop gave efficient weed control and economic yield of rice in the rice based cropping system involving rice – rice – fallow of Onattukara region.
