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ThesisItem Open Access Selection for mosaic resistance in pumkin (cucurbita moschata poir)(Department of Olericulture, College of Horticulture, Vellanikkara, 1992) Latha, P; KAU; Gopalkrishnan, T RThe investigation “Selection for mosaic resistance in pumpkin (Cucurbitamoschatapoir)” was conducted at the College of Horticulture, Vellanikkara, Thrissur during November 1990 – April 1992. The high yielding and locally adapted variety Ambili was sown at bimonthly intervals to study the seasonal influence on mosaic incidence, vector population and yield. Incidence of yellow vein mosaic, pumpkin mosaic, bottle gourd mosaic, watermelon mosaic and cucumber mosaic were observed in crops sown during different months. Incidence of yellow vein mosaic and population of whiteflies (BemisiatabaciGenn.), the vector of yellow vein mosaic, were positively correlated with temperature and negatively correlated with rainfall and relative humidity. Fruit yield and contributing characters were significantly influenced by different dates of sowing and sowing in October was found to yield maximum because of the delayed incidence of mosaic. From the study of P1, P2, F1, F2 , BC1 and BC2 generations of the cross involving mosaic susceptible Ambili and resistant CM 214 (Nigerian Local), resistance to yellow vein mosaic was found to be governed by a single dominant gene and pumpkin mosaic by a single recessive gene. Silvery leaf trait was found to be dominant and governed by two genes. The study resulted in the identification of five promising selections from the segregating populations. Attempt was also made to improve the line CM 214 through selection. Improvement could be made in fruit set, seeds per fruit, hundred seed weight and seed germination. Germination percentage of CM 214 was significantly increased by removal of seed coat before sowing. Superior progenies of CM 214 were also selected for further improvement.ThesisItem Unknown Standardization of postharvest processing of ginger (zingiber officinale roscoe)(Department of Horticulture, College of Agriculture, Vellayani, 1992) Ajith Kumar, K; KAU; Sreekandan Nair, GInvestigation on standardization of post-harvest processing of ginger (Zingiber officinale Roscoe) was carried out at the Department of Horticulture, College of Agriculture, Vellayani during 1988 -90. Ginger rhizomes were processed to study the effect of various methods like scraping, slicing, blanching, boiling, coating and their combinations on the yield and quality of dry ginger, storage life and also on storage pests and diseases adopting CRD. In this study among the various treatments low recovery (31.6 per cent) of dry ginger was obtained for scraped ginger. The sliced rhizomes took only four days for drying. The essential oil content decreased with an increase in time. The treatments slicing and drying (T4), blanching and drying (T5), unpealed and drying (T1) scraping and drying (T3) and spliting and drying (T2) were found to be the best for longer storage. The oleoresin content also decreased with an increase in time and the treatment combinations which include boiling resulted in the maximum reduction in oleoresin content followed in the maximum reduction in oleoresin content followed by combinations of scraping and spliting. The study revealed that compared to single treatment a combination of treatments especially when boiling as a component reduced the crude fibre content. The ginger rhizomes when sliced and dried took the minimum period for drying and it resulted in the production of normal coloured product and also comparable in quality aspects. Hence slicing and drying of ginger rhizomes is an alternate method for processing of ginger.ThesisItem Open Access Leaf litter addition and nutrient recycling in rubber in Vellanikkara estate(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1992) Guruprasad, M K; KAU; Sreekandannair, GPreliminary studies on the total quantity of the leaf litter, chemical composition of leaf litter and the nutrients released through leaf litter for recycling, in an eight year old rubber plantation of Vellanikkara Estate of Kerala Agricultural University have been attempted. During the year under study, wintering started by 14th December, 1991 and continued till 2nd March, 1992, the peak being the third week of January, 1992. During annual defoliation period total leaf litter production (dry weight) was estimated to be 4112 kg/ha, the contribution of which works out to annual addition of 63.3 kg N, 2.64 kg P, 44.0 kg K, 42.32 kg Ca and 8.93 kg Mg. During wintering, there is a gradual decline in the levels of nitrogen, phosphorus and potassium in leaves due to the shift of these nutrients to trunk. This shift was not abserved in the case of calcium and magnesium. Approximate leaf area index was also worked out and is found to be 4.26.ThesisItem Open Access Cataloguing of medicinal plants in Vellanikkara rubber estate(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1992) Raghavan, K K; KAU; Sreekandan Nair, GThe investigation revealed the presence of many medicinal plants growing as undergrowths in the rubber plantation . These plants are widely used by all the sections of the population , whether directly as home remedies or in the medicament of the different indigenous systems of medicines, or indirectly in the pharmaceutical preparation of modern medicine . It can be presumed that the vast area occupied by the rubber plantation industry in our country is richly endowed with a wide variety of plants of medicinal value which represent a great national resources. Indian officially recognizes over 2500 plants as having medicinal value , and it has been estimated that over 6000 plants are used in traditional , folck and herbal medicine , represent a great national resource. Indian officially recognizes over 2500 plants as having medicinal value , and it has been estimated that over 6000 plants are used in traditional , folk, and herbel medicine , representing about 75 per cent of the medicinal needs of the country . Some of these plants are also abundant in rubber plantations. The presence of a large number of weeds having medicinal value under the shade of rubber of weeds having medicinal value under the shade of rubber plantation give influence to fact that they can be cultivated as intercrops in the plantation provided there is internal market demand and fetches a good remunerative profit . This will bring additional income to the lakhs of rubber growers from their limited unit areas. Plants like Hemidesmus indicus and Curculigo Orchioides which find a favourable growth under the dense canopy of rubber , are of much commercial importance . But the impact of cultivation of these plants on the growth and yield of rubber needs investigation . The experiments started at the Rubber Research Institute of India in this line will definitely bring out positive developments in the near future. Further about 80 per cent of the raw materials for drugs used in the Indian system of medicine and homeopathy are based on plant product s. The credibility of these systems of medicine depending available authentic raw materials in sufficient quantities. With some 46,000 licenced pharmacies manufacturing the traditional remedies of these medicinal systems, it is necessary to plan for large scale cultivation of medicinal plants and ensure that they are accurately identified , properly processed , free of adulterants and of acceptable quality . In areas where land is limiting these crops can be cultivated as intercrops can be cultivated as intercrop. More over this will be an indirect attempt for the conversation of the endangered plants of medicinal importance.ThesisItem Open Access Standardisation of softwood and epicotyl grafting in Garcinia. cambogia Desr.(Department of Pomology & Floriculture, College of Horticulture, Vellanikkara, 1992) Nazeema, K K; KAU; Lila Mathew, KThe investigations on standardisation of softwood and epicotyl grafting in Garcinia cambogia was carried out in the Department of Pomology and Floriculture, College of Horticulture, Vellanikkara, Trichur during the period, 1990-92. The studies revealed that seed coat removal or seed treatment with growth regulators increased the final percentage of seed germination compared to control though there was no significant difference between the treatments. Seed coat removal could enhance the seed germination remarkably. After the beginning of germination seeds with intact seed coat completed germination within seven weeks while those seeds without seed coat required only five weeks for the same. In order to obtain an early and higher germination, seed coat removal along with seed soaking with 500 ppm GA for 12 h could be adopted. This treatment registered 90.667 per cent germination. Softwood grafting on 18 months old G. cambogia rootstock was found to be the best method of vegetative propagation compared to epicotyl grafting (using G. tinctoria rootstocks) and double grafting (using different combinationsThesisItem Open Access Standardisation of explant for In vitro propagation in Dendrobium spp .(Department of Horticulture (Pomology, Floriculture and Landscaping) , College of Horticulture, Vellanikkara, 1992) Lakshmi Devi, S; KAU; Rajeevan, P KInvestigations were carried out at the Plant Tissue Culture Laboratory attached to All India Co-ordinated Floriculture Improvement Project (AICFIP), College of Horticulture, Vellanikkara, during 1990-91 to standardise the explants for in vitro propagation in Dendrobium spp. The explants used for the study were shoot tip, axillary bud, inflorescence stalk, leaf segments and root segments. The species of ' Dendrobium used were D. fimbriatum, D. moschatum and D. nobile. For culture establishment, proliferation of shoot/callus and _in vitro rooting studies, different sources of auxins (NAA, IBA, 2,4-D) and cytokinins (BA, KIN) were used with KC, MS and/or VW media. In all the explants, surface sterilization using 0.1 per cent mercuric chloride for 10 minutes was found to be the best. The explants collected during April recorded the minimum rate of contamination and the maximum survival percentage. Axillary bud was found to be the ideal explant for enhanced release of axillary buds. For Dendrobium moschatum, MS medium with the treatment combination of NAA 1.5 ppm + BA 1.0 ppm was found to be effective in influencing early bud initiation and elongation, but for D. fimbriatum and D. nobile, VW medium containing NAA 1.5 ppm +' BA 1.0 ppm was found to be the best. When the cultures were subjected to shoot . proliferation, VW medium containing NAA 2 ppm + BA 3 ppm gave maximum number of shoots in D. fimbriatum (18.8), D. moschatum (10.8) and D. nobile (7.6). The shoots produced at this level were well elongated and healthy. The proliferation of shoots also increased when NAA 2 ppm + KIN 3 ppm were used in VW ‘medium, but the number of shoots produced was: low, compared to NAA 2 ppm + BA 3 ppm. BA was found to be more efficient than KIN for the induction of axillary shoots. Addition of CW (15%) into the basal proliferation medium increased the number of shoots in all the three species of Dendrobium. Axillary shoots produced per culture vessel increased at a mean rate of 8.3, 7.7 and 6.6 shoots per subculture in D. fimbriatum, D. moschatum and D. nobile, respectively. For in vitro rooting, MS (half strength) medium containing IBA 4 ppm was found to be the best. Addition of sucrose at 1.5 per cent and AC at 0.10 per cent enhanced the rooting' of the shoots produced in vitro . Of the various ex plants tried for somatic organogenesis (callus mediated), root segments (aerial as well as from culture) was found to be the best explant in initiating callus. In the culture establishment, swelling of the explant was observed in modified VW medium containing NAA 4 ppm + BA 1 ppm. As regards callus induction, 2,4-D at 2,0 ppm in modified VW medium was found to be better for all the explants. Maximum callusing (Cl = 240) was observed in root from culture. Efforts to induce organogenesis were not successful.ThesisItem Open Access Impact of Additional Incentive Scheme for Rubber in Assam(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1992) Rabi, Ram Baro; KAU; Nazeem, P AAn attempt was made in this study to evaluate the impact of additional incentive scheme for rubber in Assam. There were four Rubber Board Regional Offices in the State and one Zonal Office at Guwahati. All the available data were collected from the above offices. In the surveyed area, the impact of various additional incentives was studied and interpreted.ThesisItem Open Access Major diseases affecting rubber and Its control measures adopted by small growers of Vaikom taluk(Department of Plantation Crops and Spices, College of Agriculture, Vellayani, 1992) Sreedharan, A P; KAU; Sreekantan, Nair GThe major diseases affecting rubber in Vaikom taluk were powdery mildew, pink and abnormal leaf fall. Powdery mildew was more serious and infected about 99 per cent of the holdings surveyed. Dusting of sulphur at the time of refoliation can control the spread of the disease. Use of the chemical at the recommended dose was not adopted by the growers. This can be the main reason for the spread of the disease. Infection of pink disease was not so serious in the surveyed area. About 10.7 per cent of the trees were seen infected. Detection of the diseses at the early stages of infection and treatment of the trees was more important in the control of pink. It was obvious that the farmers knowledge in plant protection techniques were poor. No grower was seen adopting thiride treatment against pink though it was recommended as effective to Bordeaux paste. Lack of awareness of growers can be the main reason. Abnormal leaf fall was the least serious among the three diseases. The clone RRII 105 showed average tolerance to the disease and that can be the reason for the mild infection of the disease in the surveyed units. The study showed extension activities among the growers were highly inadequate. RRII 105 being the main clone, the leaf retention during monsoon was satisfactory even without prophylactic spraying. Therefore, prophylactic spraying was not seen as generally accepted practice among the growers of Vaikom taluk. Powdery mildew disease was very common in the surveyed units. But, many of the growers were neglecting it. All clones were seen infected with the disease. Repeated dusting of sulphur mixed with talc can control the infection effectively if sprayed at bud break. Four to six rounds of dusting should be done for the control of the disease. Extra weeding in plantation become necessary due to leaf fall and hence maintenance cost is higher. Unavailability of plant protection equipments was another difficulty faced by the growers. To overcome these difficulties disease tolerant clones may be planted in future. Moreover, the extension methods are to be strengthened to educate the growers about the diseases and its timely control.ThesisItem Open Access Comparative study of yield performance of two important clones of rubber -RRII105 and RRIM 600 in Mooply Valley of Thrissur District(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1992) Perumal Pillai, S; KAU; Sreekantan Nair, GA comparative study of the yield performance of two high yielding clones. RRII 105 and RRIM 600 were made. The former one is recommended under category I irrespective of areas and the latter as category II in traditional areas and as category I in nontraditional areas. Two representative samples where both these clones were planted and under tapping for a pretty long period were selected and all the available data pertaining to yield were collected. The agroclimatic conditions in both the estates are similar. They were following the recommended package of practices by Rubber Board. The severity of the diseases were reduced by timely adoption of prophylactic/control measures. From the study it was observed that RRII 105 is superior to RRIM 600 in yield performance as well as in some of the secondary characters which are desirable for good planting materials. The results of the study indicated that both the clones can be safely recommended for planting in the Mooply Valley area of Thrissur district., giving more preference and greater area for RRII 105. This study also supports the recent changes made by the Rubber Board in the planting material recommendations under category I.
