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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 Standardization of growing media for dendrobiums (Qendkobium dpp.)(Department of Horticulture, Pomology & Floriculture and Landscaping, College of Horticulture, Vellanikkara, 1989) Anitha, Paul C; Rajeevan, P KThesisItem Open Access Effect of growth regulators on flowering pollination and seed-set in ginger(zingiber officinale, rose)(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1984) Usha, K; KAU; Balakrishnan, SFlowering behaviour and floral biology of Rio-de-Janeiro and Maran and the effect of growth regulators viz., kinetin (5, 10 and 15 ppm), Ethrel (25, 50 and 100 ppm) and NAA (10, 25 and 50 ppm) in combination with two per cent urea and without urea on flowering, pollination and seed-set in Rio-de-Janeiro were studied at the College of Horticulture, Kerala Agricultural university, Vellanikkara during 1981-’83. The objective of the investigation was to assess the available varieties of ginger for flowering behaviour and to evaluate the effect of growth regulators with and without urea on the flowering behaviour, floral biology, floral structure, pollination and seed- set in Rio-de-Janeiro. (The possibility of overcoming the problems of shy and irregular flowering, poor pollen germination and the failure to set seeds also was explored during the investigation). (Among the 25 varieties studied, flowering was observed only in two varieties viz., Rio-de-Janeiro and Maran). Considerable variation was noticed between Rio-de-Janeiro and Maran with respect to flowering behaviour, extent of flowering, types of inflorescence, time taken for scape development, anthesis, anther dehiscence, pollen production, pollen fertility, style length and ovary length. Long but thin style was noticed both in Rio-de-Janero and Maran. Irrespective of the variety, flowers were found to rot/ and dry within 16 hours after flower opening. The maximum pollen germination (6.20 per cent) was obtained in the medium containing eight per cent sucrose, three per cent gelatin and 60 ppm boric acid under moist cotton covering in BOD incubator (26.50C). Coiling of the pollen tube during the advanced stages of growth was noticed. Pollination carried out in Rio-de-Janeiro and Maran employing the variables like stage of flower (bud stage, immediately after flower opening and three hours after flower opening), condition of stigma (partial and complete removal of style), density of pollen (smearing once, twice and thrice with standard brush), mixed pollen (ginger pollen with either Alpinia, Hedychium, Kaempheria or Costus pollen) and supplementary pollination (repeated pollination twice at two hours interval) failed to record any positive evidence of seed-set. Effect of growth regulators and urea on flowering behaviour, inflorescence characteristics and floral structures of ginger was evidenced during the study. ( Favourable influence of NAA 50 ppm on inducing early flowering, kinetin 15 ppm on the duration of flowering, NAA and kinetin on inflorescence production, NAA 50 ppm without urea on the number of flowers per inflorescence, NAA 10 ppm and all the three levels of kinetin on pollen production, NAA on pollen diameter, higher levels of Kinetin and Ethrel and lower levels of NAA on exine thinning, Ethrel 25 ppm in combination with urea, Kinetin 15 ppm with urea, NAA 50 ppm and Kinetin 10 ppm on pollen fertility, lower levels of Kinetin and Ethrel on reducing the style length, Kinetin 15 ppm and NAA 10 ppm on ovary length, Ethrel 25 ppm with urea and higher levels of NAA and Kinetin on pollen germination and NAA 50 ppm on pollen tube growth was revealed during the study.) Floral biology of Rio-de-Janeiro was not influenced by growth regulator and urea treatments. Abnormal floral structures occurred as isolated cases and therefore the role of growth regulators and urea in this respect was not clear from the results. (Pollination carried out in ginger (var.Rio-de-Janeiro) plants, subjected to growth regulator treatments with and without urea, employing the variables like stage of flower, condition of stigma, density of pollen, mixed pollen and supplementary pollination failed to result in seed-set.)ThesisItem Open Access Effect of growth regulators and certain formulations on bunch development in banana var. palayankodan(Department of Pomology & Floriculture and Landscaping, College of Horticulture, Vellanikkara, 1983) Rajendran, P; KAU; Aravindakshan, MThe yield of banana in Kerala remains very low inspite of the adoption of proper manuring and other management practices. Investigations have indicated that the main barrier to the increased production in banana is the lack of sufficient leaf area at the active phase of growth of the plants. The present experiment was conducted with the banana cultivar ‘Palayankodan’ under sparsely irrigated conditions with a view to increase the plant growth and ultimate yield by the use of growth regulators and commercially available formulations. The growth regulators viz., 2-4-D and NAA and the commercially available formulation namely ‘Navras Banana Special’ were tried at four different concentrations as given below:- 2,4-D - 5,10,15 and 20 ppm NAA - 20, 30,40 and 50 ppm ‘Navras’ - 0.25, 0.50,0.75 and 1.00 per cent The various chemicals at different concentrations were applied as two foliar sprays at three and four months after planting. A third spray was also given on the bunches immediately after the female phase of flower opening. On an overall analysis, 2,4-D at 20 ppm and ‘Navras’ at 0.50 per cent were found to be more effective in promoting the vegetative growth of plants. With respect to flowering and duration of the crop, the growth regulators alone had significant effects when compared to the commercial preparation ‘Navras’. The effectiveness also depended on the concentrations of the growth regulators. Thus 2,4-D at 20 ppm induced early shooting of plants by about 12 days whereas NAA at 50 ppm caused substantial delay in shooting. The chemicals at their various concentrations were not effective in influencing the bunch maturity, thus indicating that the applied chemicals caused the earliness or delay observed, through their influencedon the vegetative growth only. Consequent to the application of 2,4-D at 20 ppm the crop duration was advanced by 22 days. Contrary to this, NAA at 50 ppm delayed the duration of the crop. The treatments with 2,4-D at 5 to 20 ppm, NAA at 40 and 50 ppm and ‘Navras’ at 1.00 per cent were found to advance the ripening of fruits. The best quality fruits in terms of TSS and total sugars were obtained by the application of 2,4-D at 20 ppm. Among the concentrations of ‘Navras Banana Special’, o.5 per cent gave the best results with respect to the growth and yield of plants. When the concentration was increased further, there was a decrease in the performance of the plants. The optimum doze of ‘Narvas Banana Special’ was worked out to 0.534 per cent. The correlations worked out from the data collected revealed that the vegetative and bunch characters such as girth of psuedostem, number of functional leaves, total leaf area, length of bunch, number of hands and fingers per bunch, number of fingers per hand and weight of hand, length, girth and weight of fingers amply contributed to the overall yield in the form of bunch weight. The yield increase observed in the present study due to the application of 2,4-D at 20 ppm was by 88 per cent and that for ‘Navras’ at 0.5 per cent was by 96 per cent. The benefit/cost ratio worked out for these treatments did not differ and hence application of 2,4-D (20 ppm) and ‘Navras Banana Special’ (0.5 per cent) were equally good for increasing the yield. The present investigations were conducted under sparsely irrigated conditions where, irrigation was given just for the maintence of the crop. Further investigations with rainfed and irrigated ‘Palayankodan’ bananas may be of particular interest.ThesisItem Open Access Biochemical characterisation of coconut palms in relation to yield(Department of Horticulture (Plantation Crops and Spices), College of Horticulture, Vellanikkara, 1983) Narayanan Kutty, M C; KAU; Gopalakrishnan, P KAn investigation on the morphological and chemical components of yield in coconut palms was conducted at the College of Horticulture, Vellanikkara during 1981-83, in order to characterise the yield of palms based on these characters. Sixty palms of the cultivar West Cost Tall (W.C.T.) were selected from the existing Plantation at Agricultural Research Station, Mannuthy comprising twenty palms each under low, medium and high yield groups (< 40, 40-80 and 80 nuts/palm/year respectively). Observations on morphological characters such as number of leaves, length of leaf, length of petiole, number of leaflets, length of leaflets, periodicity of leaf emergence and girth at collar were recorded at bimonthly intervals. Analysis of leaf samples from the leaf position 14 were taken up to estimate the contents of nitrogen, phosphorus, potassium, calcium, magnesium, soluble sugars, starch, total phenols, free amino acids, total chlorophyll, catalase activity and peroxidase activity during March-April and September-October seasons. There was a significant positive correlation for number of leaves, length of leaves, number of leaflets, length of leaflets and girth at collar with the mean annual yield. The periodicity of leaf emergence had a negative correlation with yield. Among the mineral nutrients, nitrogen and potassium had significant positive correlation with yield. Phosphorus, Calcium and magnesium failed to show any linear relationship. The nutrient ratios viz., N/Ca, K/P, K/Ca, K/Mg and K/Ca + Mg also exhibited significant positive correlation with yield. The biochemical components such as soluble sugars and total chlorophyll content in the leaf lamina had significant positive correlation with yield. Total phenolic compounds present in the leaf lamina had a significant negative correlation with yield. Starch content in the leaf did not show such relations. The free amino acids present in traces in the leaf were identified. Leaf catalase and peroxidase activity exhibited no definite pattern of variation in relation to yieldThesisItem Open Access Screening for resistance to aphis craccivora in vegetable cowpea and evaluation of early types(Department of Olericulture, College of Horticulture, Vellanikkara, 1984) Sulochana, K A; KAU; Peter, K VCowpea Vigna unguiculata (L) walp is an important legume grown both in tropics and sub tropics. Eighty three cowpea lines were evaluated for field resistance to Aphis craccivora. All the lines except 10 TVU lines were infested by the aphid before 30 days after sowing. The lines TVU 1889, TVU 408, TVU 2896 and TVU 2962 were completely free from aphid infestation observed on leaves internodes and pods upto 60 days of sowing during the first crop season. The resistance reaction observed during second crop season and under controlled aphid infestation revealed that TVU 1889 was the most promising as far as aphid resistance is concerned. There are considerable variability in the cowpea for different characters and the lines K 1552 and TVU 1892 were the earliest to harvest (52 days). Among the weather parameters average number of rainy days and relative humidity had negative relationship with aphid population. Fifteen selected varieties of vegetable cowpea were grown in two seasons under two fertility levels. There were considerable variability in the vegetable types of cowpea for earliness which is important for the crop to be fitted in a multiple cropping system. The variety K 1552 was the earliest (52.13 days) followed by K 868 (52.43 days). The line IIHR 6-1-B is the most average stable variety with the highest mean (62.35 g) and bi value tending to one (0.96). The varieties K 1552, VS 89 and K 868 were high yielders but had bi value more than one and are suited for high yielding environments. The chemical analysis of pods for monosaccharides to polysaccharides ratio indicated that the yard long bean had the highest ratio followed by K 1552, IIHR 6-1-B and VS 87.ThesisItem Open Access Effect of gamma irradiation in ginger(Department of Horticulture (Plantation Crops and Spices), College of Horticulture, Vellanikkara, 1984) Giridharan, M P; KAU; Balakrishnan, SInvestigation was carried out at the College of Horticulture, Vellanikkara, during 1983 – 84, to study the effect of gamma irradiation on germination, vegetative growth, flowering, yield, quality attributes and incidence of soft rot disease in ginger using four doses of gamma rays (0.7, 1, 1.5, 2.k rad). Irradiation treatments produced inhibitory effects on the germination of ginger rhizomes. The plant height, tiller production, leaf production, leaf size and leaf area index decreased with the increase in irradiation dosages. Flowering behaviour of ginger could not be altered by the levels of gamma irradiation tried. Rhizome yield reduced as the irradiation dose increased. The treatments did not differ significantly with regard to essential oil and oleoresin content of both green and dry ginger ; oleoresin of ginger peel and percentage recovery of dry rhizomes. However, the incidence of soft rot disease could be highly reduced by gamma irradiation.ThesisItem Open Access Studies on the fermentation and curing of cocoa beans(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1983) Premalatha, T; KAU; Mohanakumaran, MInvestigations conducted at the College of Horticulture, Vellanikkara during 1979-81 indicated mini- basket lined with banana leaves and mini- box as the methods suitable for fermenting small quantities of beans . These methods were chosen from among the seven studied , based on the temperature development in the ferment and on the result s of the cut test. Polythene sheet was found to be a poor insulating material as compared to banana leaves having led to unsatisfactory aeration and low temperature build up during fermentation. Fermentation during the dry season was found to be better with respect to the fermentation characteristics and physical quality characteristics of the beans. Fermentation of beans from yellow /ripe pods and over-ripe pods gave higher proportion of commercially acceptable beans . The cured beans had desirable PH and good physical quality characteristics. Storing the harvested pods for two to six days before the extraction of beans for fermentation led to the development of optimum temperature in the ferment , desirable pH in the dried and the production of a higher proportion of commercially acceptable beans. Storing the cured beans increased the proportion of commercially acceptable beans . An increase in the pH of the beans was also observed during the 28-week storage.ThesisItem Open Access Evaluation of a set of non-segragating and segragating populations of tomato for field resistance to bacterial wilt(Department of Olericulture, College of Horticulture, Vellanikkara, 1985) NarayananKutty, C; KAU; Peter, K VBacterial wilt caused by Pseudomonas solanacearum E.F. Smith is the single limiting factor for tomato cultivation in the warm humid tropical soils of Kerala. The susceptibility of reportedly resistant varieties elsewhere necessitates the need for continuous evaluation of tomato lines for wilt resistance. An experiment was planned and carried out during 1983-’85 at the College of Horticulture, Vellanikkara to identify new sources of resistance to bacterial wilt. The susceptible check Pusa Ruby showed 100% susceptibility in all the trials. The F2 hybrids of Saturn and LE 79 were found resistant, out of the four non-segregating (Saturn, LE 79, Pusa Ruby and Pusa Ruby x LE 79 F1) and two segregating populations (Pusa Ruby x LE 79 F2, Saturn x LE 79 F2) evaluated. In a repeated trial F3s were also evaluated along with the F2s and non-segregating populations (Saturn and FE 79). Resistance was observed in Saturn x LE 79 F3 (percentage wilt, 10.7) and Saturn x LE 79 F2 (percentage wilt, 18.23). Pusa Ruby x LE 79 F2 s and F3s were susceptible to moderately susceptible. Among the non-segregating populations, LE 79 showed moderate resistance, while Saturn was moderately susceptible to susceptible in both the trials. Information on days to fruit set, days to harvest, fruit yield/plant and average fruit weight were also gathered. A higher average fruit weight (44.63g) was observed in the resistant Saturn x LE 79 F3s. Evaluation of 15 reportedly resistant lines of tomato confirmed resistance in LE 79 LFG and LE 217. The line LE 79 LFG was also medium fruited (40.1g) and high yielding. Concentric cracking and irregular cracking were observed higher than radial cracking in all the lines evaluated. Fruit set ranging from 50 to 63% was observed in all the lines at higher night temperatures (230C average). Genetics of fruit shoulder colour revealed that white colour was recessive to green and governed by a single gene. Evaluation techniques like root dipping in bacterial culture and planting, stem inoculation in leaf axil and alternate row planting were compared with spot-planting for efficiency. Spot-planting was found easier and effective. The chances for escape are negligible in this method of evaluation.
