Browsing by Author "Robert Cecil, S."
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Item Calcium and Magnesium nutrition of coconut palm(2007-02-08) Robert Cecil, S.Item Chemical studies on the leaf and root (wilt) diseases of coconuts in Travancore-Cochin : III. Reduction products formed under waterlogged conditions: Preliminary investigations(2007-02-08) Robert Cecil, S.; Verghese, E.J.Item Effect of agro-techniques on the root (wilt) disease of coconut(2007-02-08) Sadanandan, A.K.; Pillai, N.G.; Robert Cecil, S.The various agro-techniques including planting techniques, nutritional and irrigation requirements of young and adult palms, inter and mixed cropping in coconut garden, crop - livestock - fisheries integration techniques etc. under the geo-pedo environments of Central and South Kerala for containing the root (wilt) disease of coconut are discussed. The root (wilt) disease of coconut, noticed first in 1882 in Central Kerala, has now spread upto Trichur district in the north and Trivandrum district in the South. The disease has also been recently noticed in two villages of Kanyakumari district in Tamil Nadu. Palms of all ages are affected. The disease spreads at 1-4 km per year and has now affected about 12 million palms in 250,000 ha extending to nearly one third of the total coconut area of Kerala. The economic loss due to the disease is Rs. 300 million annually. The research on the disease was started as early as in 1937 and intensified in 1948. The etiology of the disease has not yet been clearly understood. And therefore no specific control measures could be advocated. However, the results of research carried out so far by the CPCRI at its Regional Station, Kayangulam and elsewhere showed that a package of agro-technology could be drawn out for mitigating and/or arresting the disease. These are enumerated in this article. The climate of the region is of humid tropical with an annual rainfall of 2284 mm received in 120 rainy days. The soil types are loamy sand/sandy loam and poor in N,K, Ca, Mg and micronutrients. The management practices adopted for the main crop of coconut and the subsidiary crops grown in the coconut gardens are given in Table I.Item Effect of application of N, P, K, Ca and Mg on young West Coast Tall palms in the root (wilt) affected area(2007-02-08) Robert Cecil, S.; Pillai, N.G.; Mathew, A.S.; Kamalakshi Amma, P.G.The response to three levels of N, P and K and two levels of Ca and Mg by WCT palms from the seedling stage was studied in a 33 x 22 factorial split experiment conducted in loamy sand soil at CPCRI, Regional Station, Kayangulam since 1970. The fertiliser levels (adult) are: 500,750, 1000 g N; 300, 450, 600gP2O5; 1000, 1500, 2000 g K20; 0, 12.5 kg Ca (OH)2 and 0, 500 g MgO. The lime was applied broadcast uniformly and ploughed in, while the other fertilisers were applied only in the basins. The effect of application of N was found significant in increasing the height of seedlings during the first year but not during the later years. The main effect of P was not found favourable on any of the characters. The effect of K was significant in increasing the girth at collar only during the third year. The response to Ca was significant in increasing the height of seedlings during the third year, but was highly significant on the number of functioning leaves during the fourth year. The main effect of Mg was highly significant in increasing the girth at collar, height, number of leaves produced, number of functioning leaves, early flowering and the cumulative yield of nuts harvested upto the seventh year. Irrespective of the treatments given, 19% of the palms had contracted the root (wilt) till December, 1977.Item Effect of major nutrients on the incidence of root (wilt) disease in coconut(2007-02-08) Robert Cecil, S.; Pillai, N.G.; Kamalakshi Amma, P.G.; Mathew, A.S.; Nambiar, P.T.N.Studies on the effect of application of N,P,K, Ca and Mg, from die time of planting in the main field at Kayangnlam, on the incidence and severity of root (wilt) disease in West Coast Tall palms indicated that, young palms are more susceptible to the disease at the onset of bearing. When young palms under good management contracted the disease before flowering, the onset of bearing was delayed by about 12 months. The frond production rate and the number of functioning leaves on the crown are considerably reduced in diseased palms. Among the nutrients, Mg significantly increased the expression of both these characters thereby preventing the reduction in growth due to the disease. The disease caused about 60 per cent reduction in yield in the early bearing period. The mean yields of healthy and diseased palms at the 10th year of planting were 58.8 and 23.8 nuts/palm respectively. The disease caused about 12 per cent reduction in copra weight per nut while the reduction in oil content was not significant.Item Effect of major nutrients on the incidence of root (wilt) disease in coconut(1982-12) Robert Cecil, S.; Pillai, N.G.; Kamalakshi Amma, P.G.; Mathew, A.S.; Nambiar, P.T.N.Studies on the effect of application of N,P,K, Ca and Mg, from die time of planting in the main field at Kayangnlam, on the incidence and severity of root (wilt) disease in West Coast Tall palms indicated that, young palms are more susceptible to the disease at the onset of bearing. When young palms under good management contracted the disease before flowering, the onset of bearing was delayed by about 12 months. The frond production rate and the number of functioning leaves on the crown are considerably reduced in diseased palms. Among the nutrients, Mg significantly increased the expression of both these characters thereby preventing the reduction in growth due to the disease. The disease caused about 60 per cent reduction in yield in the early bearing period. The mean yields of healthy and diseased palms at the 10th year of planting were 58.8 and 23.8 nuts/palm respectively. The disease caused about 12 per cent reduction in copra weight per nut while the reduction in oil content was not significant.Item Effect of N, P, K, Ca and Mg on Leaf Nutrient Content and Yield of Young Coconut(2007-02) Robert Cecil, S.The effect of graded doses of nitrogen, phosphorus, potassium, calcium and magnesium on the yield, yield attributes and leaf nutrient concentration of young coconut palms of West coast Tall variety is presented hereunder. Application of all the nutrients except phosphorus increased the concentration of these nutrients in the leaf. However, the effects of nitrogen and potassium were significant only in the initial years. Applied phosphorus had only marginal influences on leaf phosphorus. Higher levels of nitrogen, phosphorus and potassium had no significant influence over the lower levels on the yield and yield attributes. The main effect of magnesium was significant on the yield and yield attributes. The direct and indirect effects of soil and leaf nutrient concentrations on the yield are also discussed.Item Effect of zinc and molybdenum on root (wilt) affected coconut palms(2007-02-08) Mathew, A.S.; Jose, A.I.; Jose Abraham; Robert Cecil, S.; Kamalakshi Amma, P.G.Item Effect of zinc and molybdenum on root (wilt) affected coconut palms(1986) Mathew, A.S.; Jose, A.I.; Jose Abraham; Robert Cecil, S.; Kamalakshi Amma, P.G.Item Electron microprobe X-ray microanalysis of diseased coconut (Cocos nucifera) roots(2007-02-08) Biddappa, C.C.; Robert Cecil, S.Electron microprobe X-ray analysis of root (wilt) diseased and healthy coconut roots were scanned for the deposition of metal ions to implicate the involvement of these metal toxicity in the root (wilt) disease of coconut. The results indicated that a high concentration of Al, Mn, Cu and Co ions localised in the disease roots compared to healthy palms. The chemical analysis of tissue samples and soils also confirmed the results of XMA.Item Impact of root (wilt) disease on the yield of young coconut palms(2007-02) Jacob Mathew; Gopinathan Pillai, N.; Kamalakshi Amma, P.G.; Robert Cecil, S.When young West Coast Tall palms under regular fertiliser management contracted the disease during the pre-bearing period, the onset of bearing was found to be delayed. While about 90 per cent of the healthy palms flowered by the end of the eighth year, it was only around 70 per cent in palms which contracted disease during the pre-bearing stage. About 18 per cent of these diseased palms did not flower even up to the thirteenth year. Decline in yield was faster in palms which became diseased in later years. In general, about 45 per cent decline in yield was observed in diseased palms, during the course of 10 years, compared to the yield of healthy palms, while in palms which were diseased during the initial years, this loss was to the extent of 68 per cent. In Dwarf x Tall palms though the occurrence of disease was at a slower rate the increase in the disease index was higher compared to that in WCT palms. The diseased Dwarf x Tall palms, in general were giving about 60 per cent lower yields, compared to the healthy palms.Item Improving the Coconut Production : Future Needs Related to Nutritional Aspects(2007-02) Hameed Khan, H.; Biddappa, C.C.; Robert Cecil, S.Item Liming of acid soils is a must(2007-02) Robert Cecil, S.Item Management(2007-02) Thomas Varghese, P.; Robert Cecil, S.Item Micronutrient Distribution in the Crowns of Healthy and Root (Wilt) Diseased Palms(2007) Hameed Khan, H.; Biddappa, C.C.; Joshi, O.P.; Robert Cecil, S.Item Mineral Composition of Coconut Leaves in Relation to Root (Wilt) Disease(1975) Robert Cecil, S.The major nutrient composition of coconut leaves from healthy and root (wilt) affected palms was studied and the role of major nutrients and their balance on the incidence of disease was evaluated. The N, P, and K content did not differ between healthy and diseased palms. The Ca and Mg content of healthy palms were significantly higher than those of apparently healthy or diseased palms. Evaluation of nutrient element balance indicated that the palms in the root (wilt) affected areas are in a state of unbalanced nutrition.Item Mineral Nutrition of Root (Wilt) Affected Coconut Palm(1975-09) Pillai, N.G.; Balakrishnan Nambiar, C.K.; Mathew, A.S.; Kamalakshi Amma, P.G.; Robert Cecil, S.; Ramanandan, P.L.; Kamala Devi, C.B.; Wahid, P.A.The mineral nutrition of root (wilt) affected coconut palm was thoroughly investigated by carrying out a nutritional survey, collecting soil and leaf samples of perfeotly healthy and diseased palms covering all the major coconut growing soil groups of Kerala State. The chemical analyses of these samples for both macro and micronutrients confirmed the accumulation of NPK in diseased palms. Nitrogen status of soils of disease affected tracts is higher -than that of Healthy soils. Among the secondary nutrients, deficiency of S is. evident. Imbalances in cationio ratios viz. K/Na, K/Mg, K/(Ca+Mg) and K/(Na+Ca+Mg): and anionio ratios via. P/S and N/S are quite apparent. Similarly, the defioienoies of Fe, Mn, Mo and Zn in particular in diseased palms are the other findings of great importance.Item Note on the mineral losses from coconut leaves by foliar leaching(2007-02) Robert Cecil, S.; Pillai, N.G.Item A Note on the Nutrient Element Ratio in Relation to Foliar Yellowing in Coconut Palm(2007-02) Robert Cecil, S.; Pillai, N.G.; Mathew, A.S.; Kamalakshi Amma, P.G.The major nutrient composition of coconut leaves from healthy palms and from palms affected by foliar yellowing was studied and the role of major nutrients and their ratio on the incidence of yellowing was evaluated. The N and P contents did not differ between healthy and affected palms. The K content was higher in affected palms while the Ca and Mg contents were higher in healthy palms. Evaluation of nutrient element ratio indicated that the palms affected by foliar yellowing were in a state of unbalanced nutrition, particularly among the major cations, with wider K/Ca, K/Mg and Ca/Mg ratios compared to healthy palms.Item Nutrient Management for Coconut Diseases and Disorders(2007-02) Biddappa, C.C.; Robert Cecil, S.; Hameed Khan, H.Soil and nutritional factors are known to exert considerable influence on the development, spread as well as the intensity of plant diseases, particularly when the associated pathogen is weak. The coconut palm, though appears to be sturdy, is susceptible to a variety of diseases. Most of the important diseases of the palm are generally found to occur on all soil types. However, the disease appear in a more acute form under unfavourable soil/nutritional environments. Some diseases like bud rot and leaf rot are known to be caused by pathogens; some like the tapering stem or pencil point condition are believed to be due to unsuitable soil conditions while others like the stem bleeding are known to be associated with the infestation by pathogens predisposed by unfavourable soil and nutritional factors. Certain disorders like the crown choke are caused purely by nutrient deficiency. The nutritional problems and their management for some of the diseases and disorders of the palm are reviewed and discussed.