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ThesisItem Open Access Diallel analysis in rice bean(Vigna umbellata( Thunb.) ohwi & ohashi)(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1999) Preeti, S V; KAU; Radha Devi, D SA diallel analysis in ricebean (Vigna umbellata (Thunb.) Ohwi and Ohashi) was carried out in the Department of Plant Breeding and Genetics, during 1997 - '98. The experimental material consisted of six parental lines and 30 F I hybrids, laid out in Randomised Block Design with three replications. The six parents were 3 LG, 5 LG, 6 LG, 8 LG, 9 LG, and 100 LG obtained from the germ plasm collection maintained at NBPGR, Thrissur. The observations were recorded on yield and yield attributing characters. Significant differences were detected among the mean performance of the genotypes, for all the characters studied. The combining ability analysis carried out by Method I, Model I of Griffing's approach (1956), revealed that the parent, 8LG was the best general combiner for most of the yield attributing traits. Among the crosses, 8LG x 3 LG exhibited outstanding sea for seed yield per plant. The crosses involving 8 LG were found to be good specific combiners. The combinations involving 3 LG and 6 LG also gave good specific combining ability effects. The numerical analysis by Hayman's approach indicated overdominance for almost all characters, which was confirmed by graphical analysis. The dominance of decreasing alleles in the parents was indicated by the negative value of F for all characters except, plant height, length of pods and number of seeds per pod. An almost equal distribution of genes with positive and negative effects was indicated by the ratio of H2 to 4H} for all the characters. The regression coefficient of covarince between parents and their offsprings in each array (Wr) on variance of all progenies in each parental array (Vr) did not- differ from unity, for plant height, length of pods, seed yield, 100 seed weight, days to maturity and protein content, indicating that assumption of non-allelic interaction was satisfactory for these characters. The Vr - Wr graph indicated that the parents were genetically divergent for days to first flowering, number of pods per plant, number of seeds per pod, 100 seed weight, days to maturity, root weight and nodule weight. Manifestation of heterosis was seen for all the characters studied. Among the hybrids, 8 LG x 3 LG was the most outstanding for yield and yield related characters. The crosses, 8 LG x 9 LG, 8 LG x 100 LG, 6 LG x 9 LG, 100 LG x 8 LG and 6 LG x 3 LG also performed better in yield and yield attributing characters. In general, hybrids involving 8 LG and 6 LG were found to be heterotic.ThesisItem Open Access Anthracnose disease of vegetable cowpea [Vigna unguiculata subsp. sesquipedalis (L.) verdcourt](Department of Plant Pathology, College of Horticulture, Vellanikkara, 1999) Praveen Kumar, M; KAU; Sally Mathew, KA study on vanous aspects of anthracnose disease of cowpea was conducted at College of Horticulture, Vellanikkara during 1997-98. Etiological studies revealed Colletotrichum lindemuthianum (Sacc. and Magn.) Br. and Cav. as the main pathogen causing anthracnose disease in Kerala and the pathogen was found to be seed borne. Among the 50 genotypes tested, Kanakamony was found immune to the disease and seven genotypes were highly resistant to the disease. In ( disease management studies, all fungicides, botanicals and antagonist Trichoderma viride were equally effective under in vitro and field conditions. As far as disease control, yield and C:B ratio were concerned, mancozeb was found to be the best treatment. Summer season was found to be the best season for cowpea cultivation in areas where anthracnose is a problem. In crop loss assessment, significant difference was noticed between carbendazim treated and untreated plots in case of disease infection and yield, and yield loss of 53.85 per cent was recorded under natural condition due to this-disease.ThesisItem Open Access Biocontrol of rhizome rot of ginger using selected antagonists(Department of Plant Pathology, College of Horticulture, Vellanikkara, 1999) Julie George, K; KAU; Sukumaravarma, MRhizome rot of ginger cas used by Pythium aphantdermatum (Edson) Fitzpatrick is one of the most destructive diseases of ginger in Kerala. The pathogen was isolated and its pathogenecity was established by Koch's postulates in ginger variety Rio-de-Jenerio. Among the various food bases evaluated, for the mass multiplication of selected antagonists, rice hull was found to be significantly superior to all others to obtain maximum growth for Trichoderma viride and Aspergillus flavus. For Aspergillus niger, rice bran was found to be significantly superior. The results on the effect of various treatments on germination showed that there was no significant difference among the treatments. The effect of antagonists on the pre- emergence rotting and post-emergence rotting (rhizome rot) were studied. In plots where antagonists (T viride, Aflavus or A. niger) or fungicides (mancozeb or copper oxychloride) were applied either as seed treatment or as soil incorporation at the time of planting, the pre-emergence rotting was not observed. The plot in which the antagonists T. vtride, A. mger and At flavus were applied in combination at 60 and 120 OAP, recorded the minimum rhizome rot incidence compared to other treatments. The plots in which the antagonists were applied twice, i.e., 60 and 120 OAP, the rhizome rot incidence was minimum compared to the plots with only one time application of antagonists. The maximum population of the pathogen P. aphanidermatum. was observed in plot where A. flavus was applied in combination with mancozeb. The multiplication of selected antagonists, 7: viride, A. flavus and A. niger in soil was found out by estimating their population at different stages. The population of T. virtde was maximum in plots where it was applied in combination with mancozeb in most of the period. The soil application of the combination of antagonists T. viride, A. flavus and A. niger did not affect the multiplication of anyone of them in soil. In general, soil incorporation of antagonists was found to helping in their mulitplication profusely compared to the seed treatment. The incorporation of the antagonists A. flavus and A. niger to the plots, twice was found to be superior than applying them only once, for getting maximum multiplication of propagules in soil. The result on the compatibility of antagonist with fungicide in field condition revealed that the antagonist T viride was quite compatible with mancozeb whereas A. flavus and A. niger were compatible with both fungicides tested (mancozeb and copper oxychloride). The treatments which was found to be superior in minimising the incidence of rhizome rot of ginger viz., T 16 (soil incorporation of T vir/de, A. niger at 60 and 120 DAP) and TI9 (soil incorporation of I: viride, A. niger and A. flavus) also recorded the maximum yield of ginger.ThesisItem Open Access Economics of production and marketing of tuber crops in Palakkad district(Department of Agricultural Economics, College of Horticulture, Vellanikkara, 1997) Sheena, P A; KAU; Thomas, E KThe present investigation on the economics of production and marketing of tuber crops viz. coleus, sweet potato and tapioca in Palakkad district was undertaken during the year 1994-95. The study focussed on estimation of cost and returns and marketing system. Data for the study was generated through a sample survey of farmers, village traders, wholesalers and retailers. Two stage sampling technique was adopted for the study, with panchayats selected purposively and sample farmers by random sampling method. The sample size for each crop was 50 making a total of 150 sample respondents. The results of the cost structure analysis revealed that the largest single item of expense was rental value of own land for coleus and tapioca and for sweet potato chemical fertilizer had the highest expense. Among the explicit cost items male labour accounted the highest share in coleus while rental value of own land and farmyard manure were the most important item in sweet potato and tapioca respectively. Cost A1, Cost A2, Cost B1, Cost B2, Cost C1 and Cost C2 per hectare was Rs.10101.74, Rs.13016.86, Rs.10101.74, Rs.17593.80, Rs.10743.99 and Rs.18236.05 respectively for coleus and Rs.8124.94, Rs.8124.94, Rs.13304.05, Rs.8852.50 and Rs.14031.61 respectively for tapioca and Rs.6733.13, Rs.6733.13, Rs.6733.13 and Rs.9079.94, Rs.7311.04 and Rs.9654.84 respectively for sweet potato. The average per hectare yield of coleus, sweet potato and tapioca were 9154 kg, 8801 kilogram and 7398.73 kilogram respectively. Benefit-cost ratio for coleus was Rs.2.27, Rs.1.76, Rs.2.27, Rs.1.30, Rs.2.13 and Rs.1.25 based on costs A1, A2, B1, B2, C1 and C2 where as the corresponding figures for sweet potato were Rs.1.74, Rs.1.74, Rs.1.74, Rs.1.29, Rs.1.60 and Rs.1.21 respectively. In the case of tapioca Benefit cost ratio was Rs.3.19, Rs.3.19, Rs.3.19, Rs.1.95, Rs.2.93 and Rs.1.85. The income measures in relation to different cost concepts, in coleus cultivation such as gross income, farm business income, family labour income, net income and farm investment income were Rs.22884.72, Rs.12782.98, Rs.5290.92, Rs.4648.67 and Rs.12140.73 respectively and Rs.11734.04, Rs.5000.91, Rs.2654.10, Rs.2076.20 and Rs.4423.00 respectively for sweet potato and Rs.25895.56, Rs.17770.62, Rs.12591.51, Rs.11863.95 and Rs.17043.06 respectively for coleus. Functional analysis was carried out using Cobb-douglas production function and the results revealed that for coleus fertilizer was found to be negative and significant. The production elasticity of labour was negative and insignificant. Farmyard manure and planting material were found to be insignificant. With regard to sweet potato labour was found to be negative and significant and the production elasticity of fertilizer was found to be negative though insignificant. Farmyard manure and planting material was found to be significantly influencing production. Regarding tapioca the production elasticity of labour and farmyard manure was found to be negative though insignificant. The high value of production elasticity of area indicated the dominance of this particular factor. Marginal value product of farmyard manure and planting material for coleus and sweet potato were greater than their factor cost ratio and was negative for labour and fertilizer. In the case of marketing of coleus and sweet potato more than 95 per cent of the produce was sold to wholesalers through commission agents. The producer’s share was only 34.53 per cent and 31.76 per cent of the consumers’ rupee for coleus and sweet potato respectively. The index of marketing efficiency was 0.53 for coleus and 0.47 for sweet potato. Regarding tapioca the tubers who performed the role of commission agent and from them produce is taken by mill owners of Salem and Dindigul. Since there is a product diversification the marketing of tapioca tubers was studied only upto the intermediary level.ThesisItem Open Access Developing baked and confectionery products based on sweet potato(Department of Home Science, College of Agriculture, Vellayani, 1999) Elizabeth, Augustine; KAU; Chellammal, SA study on ‘Developing baked and confectionery products based on sweet potato' was conducted with major objective to develop value added baked and confectionery products based on sweet potato flour. The study comprised of standardisation of raw materials, product development, assessing nutritional significance, organoleptic quality studies, preference tests and shelf life studies. The five baked and five confectionery products was formulated with sweet potato flour as the basic ingredient. Three combinations were tried with different proportions of sweet potato flour. The other ingredients added to sweet potato flour were maida, egg, sugar, ghee and skimmed milk powder. The selection of best combination was based on amino acid scores chemical scores and cost benefit ratio. A combination with 50 per cent sweet potato flour and 50 per cent maida was selected as the ideal combination, since it secured higher amino acid score and chemical score. The cost of the combination was also found to be satisfactory. The nutritional composition of the food product revealed that the product contained all the nutrients in optimum quantity. The nutritional quality of the developed food products after processing with reference to calories, proteins, β carotene, calcium, phosphorous and zinc were determined through suitable laboratory techniques. ISI type tests specified to such products were administered to the developed foods and the values were comparable with ISI specification. Organoleptic studies of the developed food products was assessed by two groups of consumers viz., college students and technical experts. The parameters tested were appearance, colour, flavour, texture and taste. The analysis revealed that both the baked and confectionery products got highest scores. Baked products had a slightly higher mean score, compared to confectionary products. In the preference tests of the developed products conducted among farm women of Venganoor, Srikariyam and Kaliyoor panchayath and entrepreneurs in Thiruvananthapuram city were also showed the same result. Moisture and insect infestation were-lower in flour stored in glass and plastic containers. Effect of storage on moisture and over all acceptability were revealed that there was an increase in moisture content during the fourth week of storage period. There was an increase in moisture during storage and the difference was statistically significant. The overall acceptability was found to be decreased after storage. There was no insect infestation in the developed products during the storage period. The assessment of microbiological quality revealed that all the products were attacked by different types of microorganisms. The result of the present study suggest that new methods of processing could be introduced to add value to the crop and it is possible to develop different types of processed products based on sweet potato products which may result in increased consumption of tuber in the future and also for building up a healthy rural population.ThesisItem Open Access Investigation on allelopathic influence and control of purple nuts edge(Department of Agronomy, College of Agriculture, Vellayani, 1999) Ameena, M; KAU; Sansamma, GeorgeLab and field experiments were conducted at the Instructional farm, College of Agriculture, Vellayani to study the allelopathic influence of Purple nutsedge (Cyperus rotund us L) on important field crops; to investigate the effectiveness of systemic herbicides for control of nutsedge and also to assess the effect of chemical weed control on growth and yield of subsequent field crops. In Ex. no. I, allelopathic influence of purple nutsedge on important field crops like rice, ragi, cowpea, green gram, bitter gourd and bhindi were studied. The treatments comprised of aqueous extracts and blended extracts of fresh and dry plant parts of nutsedge. The results revealed that aqueous extracts of nutsedge inhibited germination of rice, ragi, bitter gourd and bhindi while it had some stimulatory effect on germination of cowpea and green gram. The early growth characters of the field crops were found suppressed by the aqueous extract treatment while the blended extract showed no effect. In general, the dry plant parts showed greater effect than the fresh material. Under Ex.no.Il, field studies were made to investigate the effectiveness of systemic herbicides viz. Glyphosate and 2,4-D for control of nutsedge. The treatments included different doses of the herbicides with and without adjuvants and Glyphosate combined with sublethal dose of 2,4-D. The results revealed that lowest dose of the herbicides were sufficient for complete kill of the purple nutsedge plants in the experimental area and there was no regrowth upto 6 weeks. There was significant reduction in viability of tubers collected one month after herbicide application, but the tubers tested 45 days after spraying showed an increase in germinability over the record on 30th day. Tubers from treatments involving Glyphosate with sublethal dose of 2,4-D recorded the lowest sprouting percentage indicating the possibility for weed control for a longer period. In Ex. no. In, the persistence of the herbicides in soil were monitored and it was observed that early growth of cucumber sown on the same day of herbicide application was affected while that sown on soils collected 10 days after spraying recorded growth characters comparable to that of control. From Ex.no.IV, it could be inferred that chemical weed control did not show any deleterious effect on growth and yield characteristics of ragi and cucumber sown 15 days after the treatments. Application of 2,4-D for nutsedge control was found superior to other treatments in terms of net income and B:C ratio and the lower unit cost of the chemical was precisely the reason for its superiority.ThesisItem Open Access Evaluation of multi x bi bivoltine hybrids of silkworm(1998) Rajeni, Narayanan; KAU; Ranjith, A MIn a study undertaken to evaluate the region and season specific multi x bi and bivoltine hybrids of silkworm Bombyx mori, for commercial exploitation in Kerala, six hybrids of silkworm were reared using K-2 and S-36 mulberry varieties under Vellanikkara condition. The crosses used were PM x NB18, PM X NB4D2 and their reciprocals, NB4D2 x NB18 and its reciprocal and PM as check. The evaluation was carried out based on characters like leaf consumption, larval duration and weight, cocoon and shell weights, shell ratio percentage, average filament length, denier, reelability and renditta. The climatic factors were also correlated with major economic characters of silkworm. The present study confirms the superiority of bivoItine silkworm hybrids like NB4D2 x NBI8 and NB18 x NB4D2 justifying their wide acceptance in states other than Kerala. It is evident that if rearing is done in a systematic way, by strictly adhering to the brushing period in correlation with the seasons and if the use of high quality mulberry varieties is advocated these crosses will yield good returns in Veil ani kkara. Though the various economic parameters reflected a variable trend, ultimately when the average filament length/g cocoon, shell ratio percentage and cocoon weight were considered, the bivoltine hybrids performed superior to the others.ThesisItem Open Access Biocontrol of water hyacinth using fungal pathogens(Department of Plant Pathology, College of Agriculture, Vellayani, 1997) Susha Thara, S; KAU; Naseema, ADetailed study was conducted on the host range of the already identified fungal pathogens of water hyacinth viz. Colletotrichum gloeosporioides, Fusarium eguiseti and F.pallidoroseum on thirty cultivated plants including vegetables, pulses and oil seeds, field crops, fruits and forest crops and ornamental plants and forty one common weed plants which are seen in and around water ways infested with water hyacinth. It was observed that C. gloeosporioides could infect amaranthus, bhindi, chilli, Euphorbia hirta, Hydrocotyl asiatica and Phyllanthus niruri. Of the thirty cultivated plants and forty one weed plants tested F. eguiseti was seen to be pathogenic to amaranthus, Amaranthus viridis, Commelina . bengalensis, C. jacobi and Monochoria vaginalis. F. pallidoroseum could produce symptoms on napier grass, Axonopus sp., boerhaavia diffusa, C.benghalensis, C.jacobi, Echinochloa colonum, Euphorbia hirta, Justicia diffusa, J.prostrata, M.vaginalis and Oldenlandia umbrellata and Scorpia dulcis. For the effective destruction of the weed, lxl011 spores per ml concentration of Q. gloeosporioides, E. eguiseti and F. pallidoroseum were found to be more effective than lxl09 and lxl010 spores per ml concentration. Cell free metabolites of the pathogenic fungi were found to produce symptoms on water hyacinth plant. Metabolite produced by E. pallidoroseum caused considerable damage than by E.equiseti and C. gloeosporioides. When pathogens were applied singly and in combination on water hyacinth it was observed that the combined application of F. pallidoroseum and F. equiseti followed by F. pallidoroseum alone gave maximum intensity of infection. Eventhough C. gloeospoirioides gave least intensity of infection it can be used as a co-pathogen with E. eguiseti. Metabolite of the pathogens individually and in combination when applied on healthy water hyacinth plants, maximum damage was caused by F.pallidoroseum alone and the combination of metabolite of three fungi viz. C. gloeosporioides,F equiseti and F. pallidoroseum. Least damage was caused by metabolite of C. gloeosporioides. An experiment was conducted to find out suitable carrier materials for the mass multiplication and storage of pathogen. It was observed that for C. gloeosporioides maximum sporulation was in water hyacinth leaf followed by guinea grass straw and rice bran. But the spore viability was maximum for rice straw, and on coir pith. Maximum infection was caused by fungus grown on guinea grass straw and rice straw. In the case of E. equiseti spore counts was higher in guinea grass straw followed by coir pith. The spore germination was maximum in rice bran and coir pith. Maximum infection was produced by the fungi on guinea grass straw, coir pith and waterhyacinth leaf. E. pallidoroseum produce maximum number of spores on rice bran followed by guinea grass straw. It was observed that the germination percentage of spores were maximum on coir pith. Out of the six carrier materials used the fungus produced maximum infection when grown on rice bran and guinea grass straw. In the study for testing the storage life of metabolities, it was observed that the efficiency to produce symptom was reduced on storage in the case of C. gloeosporioides and E. pallidoroseum whereas for E. eguiseti on storage the effeciency of the metabolite to cause damage increased. Metabolite stored on refrigerated condition performed poorly for all the three fungi. Different methods of application of the three fungi were tried. Of the five treatments, placement of bits and dusting the inoculum along with the carrier materials produced maximum infection. In the experiment conducted to characterize the toxin presented in the cell free metabolite of pathogenic fungi, observed the presence of Fusaric acid in the metabolite of Fusarium spp.ThesisItem Open Access Distribution of extractable in soils of selected major land resource area of Kerala(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1997) Sathyanarayanan, R; KAU; Abdul, HameedThe investigation was carried out to assess the total and available micronutrients in soils of selected major land resource areas (MLRAs) of' Kerala. The micronutrients investigated in the present study were iron, manganese, zinc, copper and boron. The study was intended to establish the pattern of the distribution of micronutrients both vertically and spatially in eight MLRAs viz, Palode, Vellayani, Trivandrum, Mannar, Kottarakkara, Thakazhy, Ramankary and D-Block soil series of Kerala. Three extractables viz DTPA, EDTA and ammonium acetate were used in the analysis. The available boron content in these soils was also determined by hot water extraction method. All the micronutrients showed great variation in their distribution in the various horizons of the profiles. The micronutrients content of the soils estimated were correlated with soil properties like pH, organic carbon, CEC and clay content. They were found to be positively and significantly correlated with organic carbon, CEC and clay content while it was significantly and negatively correlated with pH. The significant correlations revealed that the micronutrient availability in these soils were influenced greatly by the soil properties mentioned above. From the results obtained, it was observed that micronutrients like iron and manganese were well supplied in all the profiles studied. The micronutrients were found to decrease with depth except in Ramankary, D-Blockand Thakazhy series where it showed an irregular trend with depth due to the peculiar hydrologic and oxidation-reduction conditions existing in these soil series. The available and total micronutrients content in the surface soils from places around the profile sites did not show any significant variation among places. In almost all the samples very high iron content was recorded.
