Browsing by Author "Thomas Varkey"
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Item Calcium and Magnesium status of soils and leaves in relation to the root (wilt) disease of coconut(2007-02-08) Mathew, A.S.; Thomas VarkeyThe healthy and diseased tracts in the northern border of root (wilt) affected area in Kerala State were studied to find out how far calcium and magnesium contents of soil and leaf were involved in the development of the disease. Soil and leaf samples from healthy and diseased tracts were collected from sandy, loamy, and laterite soils covering the coastal, midland, and hilly regions, respectively. Results indicated that the status of calcium and magnesium of soil and leaf could not be considered as a factor for the incidence of roof (wilt) disease of coconut.Item Calcium And Magnesium Status Of Soils And Leaves In Relation To The Root (Wilt) Disease Of Coconut(1976-12) Mathew, A.S.; Thomas VarkeyThe healthy and diseased tracts in the northern border of root (wilt) affected area in Kerala State were studied to find out how far calcium and magnesium contents of soil and leaf were involved in the development of the disease. Soil and leaf samples from healthy and diseased tracts were collected from sandy, loamy, and laterite soils covering the coastal, midland, and hilly regions, respectively. Results indicated that the status of calcium and magnesium of soil and leaf could not be considered as a factor for the incidence of roof (wilt) disease of coconut.Item Calcium and Magnesium status of soils and leaves in relation to the root (wilt) disease of coconut(1976-12) Mathew, A.S.; Thomas VarkeyThe healthy and diseased tracts in the northern border of root (wilt) affected area in Kerala State were studied to find out how far calcium and magnesium contents of soil and leaf were involved in the development of the disease. Soil and leaf samples from healthy and diseased tracts were collected from sandy, loamy, and laterite soils covering the coastal, midland, and hilly regions, respectively. Results indicated that the status of calcium and magnesium of soil and leaf could not be considered as a factor for the incidence of roof (wilt) disease of coconut.Item Determination of Stomatal Resistance and Transpiration Rate in the Leaves of Coconut (Cocos nucifera L.) Using the Steady State Porometer(2007) Rajagopal, V.; Chacko Mathew; Thomas VarkeyA study has been carried out to determine the Stomatal resistance and transpiration rate in the leaves of young and adult coconut palms. A comparative study made between the intact arid excised leaflets indicated that there was no significant difference between the two in their leaf diffusive resistance until five or six minutes after, excision, but increased with time. Determination of the Stomatal resistance within two minutes after excision of the leaflets, from different whorls of leaves in large number of adult palms revealed the accuracy of the values. Thus, a rapid method for the determination of diffusive resistance and transpiration rate in coconut, especially adult palms has been standardized. Results are discussed with particular reference to the practical difficulties encountered with studies on adultItem Foliar yellowing of coconut palms in healthy and root (wilt) affected areas(1979-12) Thomas Varkey; Kamalakshi Amma, P.G.; Ramanandan, P.L.; Nambiar, P.T.N.An attempt had been made to check the foliar yellowing by applying different nutrients and also its effect on growth and yield of affected palms. Foliar sprays with 2% MgSO4 and 1 % FeSCO4, and basal application of MgSO4 reduced foliar yellowing by 26% in diseased palms and 87 % in healthy palms. In diseased palms the application increased yield by 106% while in healthy palms, the increase was 95%.Item Foliar yellowing of coconut palms in healthy and root (wilt) affected areas(2007-02) Thomas Varkey; Kamalakshi Amma, P.G.; Ramanandan, P.L.; Nambiar, P.T.N.An attempt had been made to check the foliar yellowing by applying different nutrients and also its effect on growth and yield of affected palms. Foliar sprays with 2% MgSC>4 and 1 % FeSCO4, and basal application of MgSO4 reduced foliar yellowing by 26% in diseased palms and 87 % in healthy palms. In diseased palms the application increased yield by 106% while in healthy palms, the increase was 95%.Item Mixed Farming in Coconut Gardens : Economics and its Effect on Root (wilt) Disease(2007-02) Sahasranaman, K.N.; Pillai, N.G.; Jayasankar, N.P.; Potti, V.P.; Thomas Varkey; Kamalakshi Amma, P.G.; Radha, K.A mixed farming programme, consisting of cultivation of fodder grasses and legumes in the interspaces of coconut, maintaining milch cows, and recycling of cattle wastes, is in progress at the Institutes at Kasaragod and Kayangulam. Increase in nut yield, improvement of soil nutrient status, and increased activity of beneficial microorganisms were observed in the experimental plots. At Kayangulam, where the palms are affected by root (wilt) disease, foliar yellowing was reduced but the treatment had no effect on the other symptoms like flaccidity and leaf necrosis. An evaluation of the economics of the practices, taking into account alt the inputs and income from coconut and milk, showed that mixed farming could increase per hectare income considerably. Employment potential also increased several fold due to introduction of this system in coconut gardens.Item Note on the Investigations on the Nitrogen and Phosphorus Metabolism of Coconut Palm affected by Root (Wilt) Disease(2007-02) Thomas Varkey; Michael, K.J.; Ramadasan, A.Item Studies on coconut pollen with reference to the leaf and root (wilt) diseases(1960) Thomas Varkey; Davis, T.A.The number, size, percentage germination etc. of the coconut pollen in relation to the root (wilt) disease were studied at the Central Coconut Research Station, Kayangulam, Kerala. The dry pollen of a healthy coconut palm is ellipsoidal measuring about 66.4 u. by 33.2u and when it gets soaked with water, it assumes a spherical shape measuring about 49.8 along the diameter. However, the pollen from diseased palms measure less. Dimunitive ones and pollen having irregular shape are at their maximum in the case of diseased, trees in the acute condition. Even where the tree produces only a few male flowers on account of its exhaustion due to disease, the flowers were observed to have numerous normal looking pollen grains capable of germination and presumably fertilisation. The percentage of dummy pollen is higher in diseased palms and there is a correlation between the percentage and the stage of infection. It was also seen that the dummy pollen was more in the case of root (wilt) diseased palms than in. the leaf diseased ones of the same stage of infection. It was also seen that the percentage of germination of the pollen dwindles as the tree gets aggravated with the diseases. In the case of very young palms (healthy ones), the percentage germination of pollen was found to be much lower than that of healthy adult palms.Item Studies on coconut pollen with reference to the leaf and root (wilt) diseases(1960) Thomas Varkey; Davis, T.A.