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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 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 Disease resistance in the management of cowpea aphid-borne mosaic virus(Department of Plant Pathology, College of Agriculture, Vellayani, 1999) Radhika, N S; KAU; Umamaheswaran, KInvestigations were undertaken on the virus causing severe mosaic on cowpea (Vigna unguiculata (L.) Walp) in Kerala. The characteristic symptoms appeared as vein clearing, light and dark green mottling, severe mosaic, dark green vein banding, blistering, distortion and reduction in leaf size. The virus was mechanically transmitted through sap extracted in 0.01 M phosphate buffer (pH 7.0). The virus was efficiently transmitted by the aphid vector, Aphis craccivora. Seed transmission of eleven per cent was recorded in the variety Sharika. Thermal inactivation point was recorded at a range of 60 - 65° C, dilution end point at a range of 10-3 - 10-4 and longevity in vitro for four hours at room temperature (28 ± 4° C) and six hours under refrigerated condition (8° C). A. craccivora could efficiently transmit the virus with an acquisition access of ten minutes and inoculation access of one minute. Pre-acquisition starvation increased the rate of transmission while post-acquisition starvation decreased the rate. A single aphid was capable of transmitting the virus. The virus causing severe mosaic was identified as blackeye cowpea mosaic virus by ELISA. The virus could also be detected by Ouchterlony immunodiffusion test. Electron microscopic studies revealed the presence of flexuous, filamentous particles of 750 nm in length. Two varieties Co-6 and Cc-Selection were grouped as no symptom producing among 65 genotypes screened for resistance. Fifty three F2 progenies of the cross Sharika and Co-6 and twenty five F2 progenies of the cross Co-Selection and Sharika were long poded and resistant. Biochemical changes indicated a lower carbohydrate content in resistant compared to susceptible. Chlorophyll content decreased in the susceptible variety due to virus infection. Increase in protein was observed in both resistant and susceptible. The phenol content did not show variation between the varieties. Peroxidase, polyphenol oxidase and phenylalanine ammonia-lyase activities increased in the resistant variety. Bioassay of chemicals and neem oil on local lesion host (c. amaranticolor) indicated a per cent inhibition of 68.92 by neem oil in pre-inoculation application and 65.45 per cent inhibition by manganese chloride in post-inoculation application. On cowpea plants, pre-inoculation application of neem oil (ten per cent) concentration was found to be effective in reducing the symptoms due to viral infection.ThesisItem Open Access Floral biology and compatibility in gladiolus(Department Of Pomology And Floriculture,College Of Horticulture,Vellanikkara, 1999) Jisha, V; KAU; Suma, AThe present investigation on 'Floral biology and compatibility in gladiolus was conducted in the Department of Pomology and Floriculture, College of Horticulture, Vellanikkara during the period from July 1997 to December 1998. The investigations on floral biology, pollen studies and the extent of compatibility between different varieties were done in the experimental field of AICRP on Floriculture. All the varieties showed significant variation among themselves for all the characters studied. Accession-l showed maximum corm germination percentage (94.89), plant height (68.86 cm), leaf number (9.44), spike length (64.67 cm), spike yield per plant (3.11) and took minimum days for spike emergence (46.56) and first flowering (60.44 days). These desirable qualities combined in a single variety indicate its scope for using in further breeding programme. American Beauty had maximum duration of flowering (12.44 days) and highest cormel number (8.11). Agnirekha had maximum number of florets per spike (15.00) and corm weight (31.66 g). Mansoer Red had highest spike weight (25.63 g) and Wedding Bouquet had maximum floret size (11.14 cm) and cormel size (1.84). Maximum number of florets per spike was observed in Pacific. It had longest vase life (8.66 days), corm size (5.18 cm) and conn number (1.78) also. Tambri showed maximum cormel weight (4.65 g). In all the varieties fullanthesis occurred from 7.15 a.m. and peak time was 9.00 a.m. Anthers dehisced within two to three hours after unfurling of perianth .. Stigma became receptive only after it turned feathery. By 9.30 a.m. on the day of anthesis stigma turned feathery and after that upto two days it remained receptive. White Friendship had maximum pollen fertility (85.90 %) and pollen production per anther (39500) while Pacific registered highest pollen diameter (38.09 J.!). Maximum pollen germination was observed in 15 per cent sucrose + 75 ppm boric acid medium for the two varieties studied viz., White Friendship and Accession-L Pollen viabil ity was the highest when stored in desiccator at 4"C. High heritability and high genetic advance were observed in characters I ike days to first flowering, spike length and leaf area: This shows that most likely the heritability is due to additive gene effects and selection may be effective for these characters. PCV and GCV were high for leaf area, spike yield per plant, number of florets open at a time and duration of flowering and they were low in the case of vase life, spike length, plant height and leaf number. The number of florets per spike which determines the market quality had positive correlation with spike weight, number of florets open at a time and leaf area. So the number of florets per spike can be increased with the improvement of any of these characters. A straight away selection from - gennplasm lines will be very effective for making improvement in this character. The genotypic correlation coefficients were found to be higher than the phenotypic correlation coefficients for most of the characters. This indicates that the environment had lesser effects on these characters. The direct and indirect effects of 12 characters on number of florets per spike showed that spike weight had the maximum direct effect on number of florets per spike: It was followed by duration of flowering, collar girth, spike length and vase life. The direct selection for the characte-s like spike weight and duration of flowering would be beneficial for crop improvement, since these two also showed positive correlation coefficients. Negative direct effects on number of florets per spike was from days to first flowering, plant height, floret size, leaf area, leaf number and spike yield per plant. The highest positive indirect effect on number of florets per spike was of leaf area through spike weight. The indirect effect of duration of flowering on number of florets per spike through number of florets open at a time was the lowest. Ten gladiolus varieties namely, White Friendship, Tambri, Echo Saunder, American Beauty, Tiger Flame, Wedding Bouquet, Accession-l , Accession-2, Amal and Pacific were selected and crossed in all possible combinations. In Amal and Tambri there was no pod development and seed set in both cross pollination and self pollination tests. In self pollination, pod set, number of seeds per pod and weight of seeds per pod were higher than that in cross pollination. Pods took 25 to 35 days to mature. In self compatibility Accession-I had maximum -pod set (100 %) and highest number of seeds per pod (77.21). Weight of seeds . per pod was highest in Wedding Bouquet (1.36 g). In cross compatibility, the pod set was maximum in Accession-2 x White Friendship (91.78 %) and the number of seeds per pod was highest in Accession-? x Accession-I. Thc weight of seeds per pod was maximum in Tiger Flame x Amal (0.92 g). The seed germination percentage was maximum in Pacific (78.94 %) in self compatibility studies. In cross compatibility the seed germination percentage was highest in Accession-2 x White Friendship. The varieties with highest number of florets per spike, vase life and early flowering were observed in this investigation. Also the compatible varieties were identified. These varieties can be exploited in further breeding programmes in gladiolus.ThesisItem Open Access Regulation of flowering and post _harvest behaviour of Anthurium andreanum Cv . Hawaiian red(Department Of Pomology And Floriculture,College Of Horticulture,Vellanikkara, 1999) Abdussamed, K P; KAU; Valasalakumari, P KThesisItem Open Access Promotional strategy for integrated pest management in rice in Thrissur district an experimental study(Department of Agricultural Extension, College of Horticulture,Vellanikkara, 1999) Deepa, C B; KAU; Ranjan Karippai, SThe study was aimed at popularising the Integrated Pest management practices among the rice growers of Thrissur district and to formulate a strategy to facilitate the idea using the best combination of extension method and audio visual aids. The effectiveness of different treatments in terms of gaining knowledge, attitude and symbolic adoption were arrived at. The study was conducted among 120 rice growers of Pananchery Grama Panchayat of Thrissur district. The respondents were divided into groups of 30 each The dependent variables of the study were the knowledge about IPM in rice, attitude towards IPM practices and symbolic adoption. The independent variables included the personal, socioeconomic and psychological characteristics of the farmers. The distribution of respondents based on dependent variables showed that majority of the respondents where in high category regarding knowledge and in low category regarding attitude and symbolic adoption regarding IPM rice. Out of 18 independent variable studied 11 of them were significantly and positively correlated with knowledge. Seven variables showed non significant relation. Multiple regression analysis showed 65% variation with the variables related to knowledge. Correlation analysis of attitude showed a significant and positive relation with 14 variables out of 18 variables studied. The most important being scientific orientation, progressiveness, extension participation, cosmopolitness, information seeking behavior, management orientation, status of pest in field and competitiveness. Multiple regression analysis results showed a significant R- square value of 0.648 which explained 65% of the variation. The most important variables status of pests, progressiveness Correlation analysis of symbolic adoption revealed that out of 18 variables studied 14 were positively correlated with symbolic adoption. The most important variables being scientific orientation, achievement motivation, economic motivation, extension participation, extension orientation, cosmopolitness and information seeking behavior. The multiple linear regression analysis showed that 76% of the variation was explained by the selected independent variables. The variables like economic motivation, management orientation, status of pest in field and training in IPM were positively significant. Student's t- test was carried out to compare the changing knowledge, attitude and symbolic adoption of farmers after being exposed to different treatments. Significant changes were noticed after each treatment. Maximum changes were observed after T 3. ie lecture+ slide show + discussion. The major constraint observed by the farmers was the lack of expert guidance regarding IPM practices.
