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ThesisItem Open Access Investigations on intervarietal F2 hybrids in cowpea(Department of Agricultural Botany, College of Horticulture Vellanikkara, Trichur, 1981) Sumathikutty Amma, B; KAU; Narayanan Namboodiri, K MCcwpea (Vlgna ungiculata) Is the major pulse crop cultivated in Kerala where the average yield of pulses in general and Cowpea in particular is very low even under modern agronomic practices* This low productivity is mainly due to the absence of high yielding varieties suited for the different agro-climatic conditions. The varietal requirements in Cowpea, in the state vary because of the highly contrasting system of cultivation and this compels Cowpea breeders to evolve varieties of different combinations of plant, pod and seed characters, This is possible by producing different varieties combining the desirable attributes required for the diverse situations by suitable means. One of the ways by which, this can be achieved is through combination breeding in which desirable genes are pooled frcra different sources* In a previous study conducted in the Department of Agricultural Botany, the 202 genotypes v/ere grouped into 17 distinct clusters. Representing 15 clusters, 15 varieties were chosen for intervarietal hybridisation and their F^'s evaluated during 1979-80, Seeds collected from the plants of the 16 Intervariota] crosses along with their parents were used for the study. Two families In each of the 16 crosses were studied along with their respective parents for the pattern of inheritance of 15 economic characters. Most of the characters were found to be inherited as quantitative characters controlled by either polygenes or by a few major genes with their action being suitably modified by minor genes. The crosses 5 x 15 (g p .p l s . 139 x p .118) and 6 X 8 (Red Seeded Selection X Kolingipayar) were identified as suitable ones for grain - production and also for using as dual purpose Cowpea culture since they might throw segregants best suited to those purposes. For the specialised system of Cot/pea culture practised in summer rice fallows exclusively for vegetable purpose, the crosses 14 X 16 (Pannithodan-early X Kolingipayarwhite), 17 X 16 (Mancheri-black X Kolingipayar^hite) and 10 X 6 (IC. 20729 X Red Seeded Selection) appeared to be the Ideal ones*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 Variability studies in the seedling progenies of T*D coconut hybrids(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1981) Valsala, P A; KAU; Kannan, KA study was conducted at the Instructional Farm , Vellanikkara , during 1979-80 with the objective of assessing the extent of variability in the seedling progenies obtained from open pollinated seednuts of tall x Dwarf (F1) palms Seednuts were collected from 30 Tall x Dwarf F1 palms belonging to six family groups and the experiment was laid out in completely randomised design with family groups as treatment and progeny as replication The present investigation emphasised the utility of selection of high yielding West Coast Tall palms in controlled mating for the production of Tall x Dwarf hybrids and showed the stability of superiority of Tall x Dwarf hybrids even under poor environmental conditions. The percentage of vigorous , medium and poor seedlings produced by each (F1) progeny was found to be independent of the productivity of the palm under open pollinated condition . There fore , collection of seednut from high yielding TxD progenies for further propagation should be resorted with great caution . Progenies of the same parent have shown considerable difference in respect of the number of days taken for germination giving an indication of the variability existing in the TXD palme , in their capacity for production of early bearing and high yielding f2 progency. The petiolar colour of the grand parents and f1 progenies were green, while the F2 progenies showed segregation with green , bronze, orange and yellow colour. Four progenies each of grand parents Vlll/23 and l/58, and two progenies each of Vlll/158, I/76, Vlll/143 and 1/109 have been identified as prepotents on the basis of seedling performance . Seasonal variations were noticed on yield, size and weight of nuts. The total chlorophyll content in the leaves of the vigorous seedling which were potential high yielders were found to be high. Early germinated nuts produced seedling having more collar girth and as such greater vigour.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 Effects of graded doses of nitrogen , phosphorus and potassium on the growth and leaf nutrient status in cocoa(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1981) Salikutty, Joseph; KAU; Mohanakumaran, NInvestigations were carried out at the College of Horticulture , Vellanikkara during 1979-80 to study the effect of graded doses of nitrogen , phosphorus and potassium on the growth and leaf nutrient status of cocoa . The results of a pot culture experiment in completely Randomised Design revealed that growth parameters (height, girth and number of leaves) as well as dry matter production remained unaffected following the application of nitrogen , phosphorus and potassium. The studies indicated that addition of fertilisers to seedling grown in potmixture may not be necessary . It has also been observed that the uptake of nitrogen , phosphorus and potassium by cocoa seedlings was not affected by varying levels of these nutrients. Leaf ranked fifth from the apwas found to be suitable for leaf analysis in cocoa seedlings. Field grown young cocoa trees were utilised for evaluating the relationships between soil test values and leaf nutrient concentration vis a vis plant growth.The studies indicated the suitability of either fan or chupon leaves for foliar nutrient analysis in cocoa. However, indiscriminate sampling between the two types is to be avoided . No significant correlations existed between phosphorus and potassium contents in soil leaf, and tree growth.ThesisItem Open Access Maturity and post-harvest studies in mango (Mangifera indica Linn.)(Department of Processing Technology, College of Horticulture, Vellanikkara, 1982) Jessy Kuriakose, M; KAU; Damodaran, V KThe present investigations were carried out in the College of Horticulture, during the year 1979-80. The objectives were to study (i) the growth and maturity of mango fruits in order to standardise the harvest indices in five varieties viz., Bennet Alphonso, Mundappa, Suwarnarekha, Olour and Neelum (ii) the effect of different storage methods on the shelf life of fruits harvested at three different stages (A,B and C) and (iii) the suitability of the varieties for canning. Studies on physic-chemical characters of the fruits throughout the period of maturation were conducted with the view to fix optimum time for harvest. This study brought out that the length, weight, specific gravity (except for Mundappa) reducing sugar, starch and T.S.S. contents could be taken as dependable maturity standard. Based on these parameters the maturity standards have been fixed for the five varieties studied. The growth of fruits by way of increased length, girth, weight and volume was maximum during the first four weeks of maturation. From a stage to full maturity the acidity showed a declining trend while starch content increased. The change in reducing sugar content was erratic throughout the period of maturation. Towards full maturity the moisture and ascorbic acid contents showed gradual decline whereas an increasing trend was observed in case of drymatter content. As maturity advanced, the rate of increase in carotene content also increased. To prolong the shelf life, the most effective method was to store fruits in polythene bags of 300 gauge thickness along with KMnO4 which gave a mean storage life of 25.5 days. Storage in 300 gauge polythene bags alone was also equally good. The more the thickness of polythene, the longer was the shelf life. Waxing of fruits was not be effective as storing fruits in 300 and 250 gauges polythene bags, in terms of shelf life, but the extent of reduction in weight at the end of storage life was least in this method. Waxing was also effective in retention of acidity as well as ascorbic acid content during storage. In this method the total sugar content of the ripe fruits was not appreciably affected compared to other methods except control. The waxed fruits on ripening had the same extent of increase in carotene content as those under the other methods. Waxed fruits at the end of storage period had significant increase in T.S.S. content as compared to storage in polythene bags 250 and 300 gauges as well as in polythene bags 300 gauges along with waxing or KMnO4 . Storage of fruits in polythene bags of 300 gauge thickness, at the end of storage period, resulted in reduction of acidity and T.S.S. content compared to waxing. Compared to the untreated fruits, there was more retention of ascorbic acid content in this method. In terms of storage life as well as quality of fruits at ripening, the best stage for harvest was found to be B stage. Among the five varieties studied Bennet Alphonso and Neelum had better storage life followed by Mundappa, Suwarnarekha and Olour respectively. The quality of ripe fruits varied with varieties. In terms of storage life as well as quality of fruits Neelum came best. In shelf life though Bennet Alphonso came second, in quality of ripe fruits Mundappa was the second best. Neelum was found to be most suitable variety for canning followed by Mundappa. Bennet Alpphonso was the least suitable.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 Incorporation of two main sources of resistance to bacterial wilt in F1 generation of tomato lycopersicon lycopersicum (L) karst(Department of Horticulture (Olericulture), College of Horticulture, Vellanikkara, 1983) Sree Latha Kumari; KAU; Gopalakrishnan, P KBacterial wilt of tomato caused by pseudomonas solanacearum (E. F. Smith) is a serious disease causing considerable damage in crops grown in the acidic soils of Kerala. Development of resistant variety(s) could be a worthwhile attempt which would have considerable impact on tomato production in Kerala. Experiments were planned and carried out during 1981-82 at the Instructional Farm of College of Horticulture, Vellanikkara, Trichur, to incorporate two reported sources of resistance in F1 hybrids and then to find out inheritance of combined resistance to bacterial wilt. Two distinct sources of resistance one derived from Louisiana pink possessing North Carolina type of gene system and the other from P1 127805A possessing Lycopersicon pimpinellifolium type of gene system were made use in the present study. Interspecific F1 hybrids were produced between the above two sources of resistance. The F1S were selfed to generate F2S. Parental lines, F1S, F2S were further grown to evaluate the inheritance of combined wilt resistance in a field which was known for disease susceptibility and inoculum potential. The inheritance studies indicated a complementary and hypostatic type of digenic recessive gene system responsible for combined wilt resistance. Interspecific F1 heterosis was estimated. Significant negative interspecific heterosis was observed for days to first flower, days to first fruit harvest, plant height, branches/plant, locules/fruit and fruit weight. Genetic distance (D2) was calculated to find out genetic similarity/dissimilarity between Lycopersicon pimpinellifolium (LE 218) and ten lines of Lycopersicon esculentum. The line LE 217 was observed farthest to Lycopersicon pimpinellifolium (D2 = 449.87). The line LE 212 was the closest to Lycopersicon pimpinellifolium (D2 = 159.96). The line LE 217 had a disease score of two indicating high field resistance. The tomato lines were further evaluated for incidence of nematodol root knots and observed that all the lines were susceptible to nematode. The F2 lines possessing combined wilt resistance are being progressed for further study.ThesisItem Open Access Studies on the effect of containers, potting mixtures and growth regulators on growth and survival of clove seedlings(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1981) Prasannakumari Amma, S; KAU; Mohanakumar, NStudies were undertaken at the Instructional Farm , attached to the collage of Horticulture , Vellanikkara during 1979-80 to find out the methods to increase the percentage germination of clove seeds, to accelerate the rate of growth of the seedlings and to improve the percentage survival of the seedlings transplanted to the main field . The seeds collected during May ,June and July were classified as heavy , medium and light and sown with or without the pericarp . The seeds collected and sown during the month of June recorded the highest percentage of germination . However , the may seeds were superior with respect to rate of growth and vigour of the resultant seedling . Though heavy seeds recorded the highest percentage of germination , heavy and medium seeds were on par when the rate of growth of the seedlings was considered . The removel of pericarp increased the percentage germination , but did not influence the rate of growth of the resultant seedlings. G A at the concentrations ranging from 100 to 400ppm exhibited inhibitory effects on germination of clove seeds. The clove seedlings from the primary nursery when transplanted to improvised coconut husk pots filled with a mixture containing one part soil, one part sand and one part powered cowdung with bonemeal @ 2 teaspoons /pot and powered groundnut cake @2 teaspoons/pot, exhibited higher rate of growth . Sparying of GA 200ppm + urea 0.5 per cent to the clove seedlings transplanted to coconut husk pots or growing in one of the three potting mixtures tried , enhanced their rate of growth . Transferring the seedlings from the primary nursery to coconut husk pots at the second month and transplanting them to the mainfield with the container intact at the ninth month gave higher rate of survival.
