Loading...
Theses
Browse
353 results
Search Results
ThesisItem Open Access Divergence studies in pumpkin (Cucurbita moschata Pair)(Department of Olericulture, College of Horticulture, Vellanikkara, 1989) Suresh Babu, V; KAU; Gopalakrishnan, T RThe present investigation on "Divergence studies in pumpkin (Cucurbita moschat a Poir ) was conducted at the College of Horticulture , Vellanikkara, Trissur during June 1988 - Marc h 1989. Seventy one pumpkin genotypes collected from different part of India and abroad were utilized for the study. The extent of variability and divergence among 50 selected genotypes were assessed and grouped into 5 clusters based on Mahalanobis D2 statistic . Cluster I, II, III, I V and V contained 2, 7, 9, 12 and 20 genotypes respectively y . Intercluster distance was maximum between clusters I and II and was minimum between clusters III and V . Cluster I showed maximum average intercluster distance with any other cluster. Screening 71 genotypes for resistance/ tolerance to pumpkin mosaic and yellow vein mosaic diseases revealed that all genotypes except C M 214 were susceptible. Artificial inoculation studies confirmed immunity of C M 214 (Nigerian Iocal ) to pumpkin mosaic virus and yellow vein mosaic virus .ThesisItem Open Access Evaluative perception of appropriateness of the recommended fertiliser management practices(Department of Agricultural extension, College of Horticulture, Vellanikkara, 1989) Rasheed Sulaiman, V; KAU; Muraleedhara Prasad, RA study was undertaken to investigate into the extent of knowledge, extent of adoption and evaluative perception of appropriateness of the recommended fertilizer management practices among rice farmers (n=200) and Agricultural Demonstrators (n=54) in Palghat and Cannanore Districts of Kerala State. The study revealed that farmers of Palghat and Cannanore differed significantly with respect to their knowledge and adoption of fertiliser management practices with farmers of Palaghat having higher level of knowledge and adoptionThesisItem Open Access Flower bud differentiation in clove, Eugenia caryophyllus (Sprengel) Bullock & Harrison(Faculty of Agriculture, Department of Horticulture, College of Agriculture, Vellayani, Trivandrum, 1989) Pauline Lina, Edwin; KAU; Vasanthakumar, KInvestigations on flower bud differentiation in clove were carried out at College of Agriculture, Vellayani from August, 1936 to December, 1987. Bearing clove trees (seven years old) at the Instructional Farm attached to the college were utilized for the study. The plant specimens were stored in FAA (Formalin-acetoalcohol) and then dehydrated through tertiary butyl alcohol - iso propyl alcohol series. The specimens were Infiltrated and embedded In paraffin wax (m.p. 58-60'C) and sectioned In a rotary microtone. The sections were then de-waxed, stained and examined for the anatomical features and photoalerogra- phed. The weather parameters and the nutritional factors recorded daring the period of study and those during sixteen fortnights prior to differentiation, were correlated with the data on flower bud differentiation. Significant positive correlation was obtained between the maximum temperature during the sixth to tenth fortnights before differentiation and the percentage of flower buds differentiated. Sunshine hours during ninth to twelfth fort night prior to differentiation showed a positive correlation with the percentage of flower bud differentiation.ThesisItem Open Access Comparative micromorphologial and physico- chemical study of the upland and midupland laterite soils of Kerala(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1986) Sankarankutty Nair, R; KAU; Aiyer, R SThesisItem Open Access Exchangeable aluminium as an index of liming for the acidic upland soils of Kerala(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1987) Meena, K; KAU; Alice, AbrahamAluminium toxicity is the major factor limiting crop production in the acidic soils and the usual practice of alleviating aluminium toxicity is liming* / The present investigation was carried out to find out the distribution of water s dluhle and exchangeable aluminium in the acidic upland soils of Kerala and to test the suitability of exchangeable aluminium as an index for liming them* It was further programmed to find out the growth, yield and nutrient uptake pattern of two acid sensitive crops namely cowpea and fodder maize in soils under different levels of exchangeable aluminium brought out by the use of different levels of lime* Chemical analysis of eighty soil samples representing the five major upland soil types of Kerala viz* laterlte, alluvial, red loam, sandy and forest a oil have indicated the highest amount of exchangeable aluminium and percentage aluminium saturation in the laterite soils* The soil with 3 high level of exchangeable aluminium and percentage aluminium saturation was selected for conducting a pot culture experiment to test the suitability of using exchangeable aluminium as an index of liming* The exchangeable aluminium content of this soil was maintained at different levels by applying different levels of lime and the performance of these crops in this soil was compared by making biometric observations and by chemically analysing plant and soil samples* From the results of the study it was seen that higher levels of exchangeable aluminium adversely affected the growth, yield and nutrient uptake In cowpea and fodder maize* Maintenance of exchangeable aluminium at 1*26 me/100 g with a corresponding percentage aluminium saturation valua of around 30, by the use of 500 kg lime/ha appeared to be the optimum for maximising the yield of cowpea* But in fodder maize this level of lime was found to be insufficient and complete elimination of aluminium toxicity appeared to be essential for maximising production* Since the critical levels of exchangeable aiuainiua appears to be different for different crop3, it is desirable that lias levels to reduce exchangeable aluminium to such a critical level alono be applied. The results of the present study thus point to the advantage in adopting the exchangeable aluminium level of soil as a better index of liming for various crops grown in the upland acidic soils of Kerala.ThesisItem Open Access Time of application of pre-emergence herbicides in dry-sown rice(Department of Agronomy, College of Horticulture, Vellanikkara, 1989) Suja, G; KAU; Abraham, C TThesisItem Open Access Forecasting models for crop yield in cashew (anacahdium occident ale l.)(Department of Statistics, College of Veterinary and Animal Sciences, Mannuthy, 1987) Usha, Menon R; KAU; George, K CThesisItem Open Access Spatial arrangement and nutrient management for maize- fodder cowpea intercropping in rice fallows(Department of Agronomy, College of Agriculture Vellayani, Trivandrum, 1989) Geetha Kumari, S; KAU; Mohamed Kunju, UAn investigation was carried out during the summer season of l987-88 in the instructional farm attached to the College of Agriculture Vellayani to determine the best crop arrangement for a grain maize fodder cowpea inter cropping in summer rice fallows under different fertility levels • The different crop arrangements. tried were pure crop of maize at normal row arrangement, maize at normal row arrangement, + one, row of cowpea in between the maize pure crop of maize at paired row arrangement two rows of cowpea in the interpair spaces maize at paired rows of cowpea.ThesisItem Open Access Estimation of induced variability in chillies(Department of agricultural botany , College of agriculture Vellayani, Trivandrum., 1985) Lekha Rani, C; KAU; Krishnan Nair, NThe mutagenic effect of Co-gamma rays and Ethylmethane sulphonate on three different chilli varieties have bean studied in detail in generation U3 ing two moderate doses of gamma rays <20 and 30 kR) and two concentrations of ISMS (0.5 and 1*0 par cent)* The presence and extent of chimeras and their relation to induced variability was assessed by raising branch-wise progenies in ^ generation* The experiment was conducted during 1982-84 at the Department of Agricultural Botany# College of Agriculture, Vellayani* The generation was laid out in RBD and in splitplot design with proper randomisation and replications* The crop wa3 raised and maintained following the Package of Practices recommended. The polygenic traits analysed in a, generalisen include plant height, number of branches per plant, fruit yield per plant and length and weight of fruits. The data collected were statistically analysed for proper interpretation of tho results obtained. It has been observed in almost all the polygenic traits that the extent of variability created vary depending on the genotypes, mutagen and their dosos and character under observation. The mean values wer« found to shift both in negative and positive directions to control values• significant shift in mean values depending on the type of branch category clearly demonstrates that there exists the mechanism of diplontlc selection in this particular crop variety# when exposed to mutagens. But the extent of selection varies depending on the mutagen and their doses and the genotypes concerned. a significant negative shift in mean Value was noted only in the case of fruit weight under both the concentrations of EM3 and 20 kR gamma rays whereas a positive or negative insignificant shift was noted in all other characters under both the mutagens, when under EM3 and in gansna rays showed a negative shift* positive shift in mean value wes noted in majority of the cases for number of branches per plant. Fruit length and weight and number of seeds per fruit showed a negative shift in majority of the cases analysed# but fruit number and yield per plant showed a reverse trend. The shift in mean value under the different branch categories varied depending on the varieties# mutagens and their doses and also the character under study. The phenotypes were found toAdistributedboth in negative and positive directions to control group in all the characters analysed. The frequency distribution whether negative or positive varied depending on the mutagen and their doses# the genotypes and character under study. In majority of tha cases the maximum frequencies of positive variants under both the concentrations of EMS and under 0.5 per cent for negative variants were found to be in the early formad branches when it was in the later ones is tha case of negative variants under 1.0 per cent EMS. in the case of gamma rays this general trend was not observed* The data analysed clearly demonstrate the existence of diplontic selection and promises wide scope for positive selection response either in negative or positive directions.
