Fourteen organic materials were collected from five coconut growing areas in

Coconut (Cocos nucifera L.) yield is greatly influenced by environmental factors with rainfall playing a major role in replenishing the soil moisture reservoir within the root zone. Soil water deficits reduce transpiration from the palm, leading to an increase in canopy temperature which in turn could reduce photosynthesis and yield. The primary objective of this study was to investigate the effects of drip irrigation on temperature changes in the canopy microclimate, leaf gas exchange, flowering and nut setting of mature coconut palms. Three water regimes were imposed on 20 year old coconut palms and the above-mentioned parameters were observed over a period of two years.Results showed that irrigation lowered the temperature of the canopy microclimate and the nut surface temperature, and thereby reduced the possibility of empty nut formation during dry spells. Further, irrigation reduced stomatal resistance and thereby probably nullified the effects of drought on photosynthesis. Irrigation increased the female flower production and reduced immature nut fall during droughts, thus improving the yield. Application of 80 litres of water per palm per day lowered the canopy temperature more than 40 litres of water and significantly improved female flower production and nut setting.

Studies were carried out on a seven-year-old dwarf x tall (CRIC 65) hybrid coconut to evaluate the usefulness of goat manure as a source of nutrients and as a soil ameliorant.Goat manure caused significant increase in nut yield (35.2%), copra weight (40.3%), nuts/bunch (20.5%) and female flowers/tree (15.5%) during the third year of experimentation. The increases for copra weight, nut weight, female flowers/bunch and number of bunches/tree ranged from 6.1% to 10.1% but were not significant.Goat manure also improved soil microbiological activity, organic matter content and water holding capacity. The results showed that goat manure has much scope as an organic fertilizer and as a soil ameliorant in coconut cultivation.

The study was planned to find out the effect of different fertilizers on the growth of coconut seedlings, availability of some nutrients and soil microbial activities with the aim of developing a fertilizer mixture that supports the plant growth with simultaneous improvement of soil health. Eight months old coconut seedlings of CRIC 65 cultivar was planted in large pots and kept inside a green house. Six treatments: control (T1), inorganic fertilizer (T2), BioGold® (T3), cattle manure (T4), Kochchikade biofertilizer (T5) and compost (T6) were selected. Biweekly measurements of growth parameters, soil chemical parameters: pH, electrical conductivity, levels of K, P, Mg, and soil microbial parameters: biomass carbon and CO 2 evolution were taken. The experiment design was a Complete Randomized with three replicates. The data were analyzed by analysis of variance (ANOVA) using the MINITAB statistical package. No significant differences (P<0.05) were observed in growth parameters, soil pH and EC throughout the research period in any of the treatments. The highest P level and lowest K level were observed in inorganic treatment after a six months period. Cattle manure contributed a high level of Mg to the soil. And hence possible to recommend cattle manure as a good source of Mg. Significantly improved microbial activity was observed in BioGold® and the compost treatments. This implies that organic fertilizers are more environmental friendly compared to inorganic fertilizers.

The performance of goat dung in gravel soil commonly found in coconut lands of the low country wet zone was investigated. Goat dung was applied a t the rates of 18 and 24 kglpalmJyear and compared with treatments comprising recommended inorganic coconut fertilizer mixture (CU,) and the control (only dolomite). Dolomite a t the rate of 500g/palm/year was included in all treatments as a basal application. The microbiological (i.e. total bacterial count, total fungal count, biomass C, CO, evolution, N mineralization rate, nitrification), chemical (i.e. total-N, available P, exchangeable K) and physical (i.e. moisture) changes of soil after the application of various treatments were assessed over a 12 month period. Application of organic manure supplemented with inorganic fertilizers and only inorganic fertilizer mixture, significantly iricreased (p I 0.001) microbial counts and microbiologically mediated processes in the soil compared with the control. Addition of goat dung supplemented with inorganics brought about significantly higher (p I 0.001) microbiological activity in the soil'over only inorganic fertilizer treatment. The microbiological parameters showed positive correlation with physical/chemical parameters. Important yield parameters of coconut such a s female flowers, number of nuts and copra content per palm per year also showed increases of 49%, 61% & 58%, respectively in treated palms compared with control in the third year after the application of manure/fertilizer. Organic manure treated palms gave a significant increase (p S0.05, only in the female flower production.