Browsing by Author "Narayana, K.B."

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    Comparative efficiency of selected phosphates as P-carriers for coconut (Cocos nucifera L.)
    (2007-02-08) Hameed Khan, H.; Sankaranarayanan, M.P.; Joshi, O.P.; George, M.V.; Narayana, K.B.
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    Comparative efficiency of selected phosphates as P-carriers for coconut (Cocos nucifera L.)
    (1985) Hameed Khan, H.; Sankaranarayanan, M.P.; Joshi, O.P.; George, M.V.; Narayana, K.B.
    The results of a field experiment conducted for six years on laterite soil showed that single superphosphate, ammonium phosphate, nitrophosphate and rock phosphate had similar effects on the yield of nuts palm yr . However, when percentage yield increase over pretreatment yield was computed, rock phosphate proved best, followed by ammonium phosphate. Regression analysis revealed an optimum interaction between soil available P and leaf P for rock phosphate. The soil available P increased with the increase in the levels of P applied. Nitrophosphate increased the soil available P to a maximum, followed by ammonium phosphate, single superphosphate and rock phosphate. Fertilizer-P application generally reduced soil pH which was most marked with ammonium phosphate. The treatments showed marginal mobility of P to the subsoil which has been attributed to mechanical movement as a result of cultural operations in the coconut basin. Higher levels of applied P influenced the leaf P values which were not reflected in the yield. Costs of fertilizer indicated that rock phosphate as a P-carrier is cheapest.
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    Effect of phosphorus skipping on the yield and nutrition of coconut palm (Cocos nucifera L.)
    (2007-02-08) Hameed Khan, H.; Sankaranarayanan, M.P.; George, M.V.; Narayana, K.B.
    The skipping phosphorus fertiliser application to adult coconut palms has resulted in the reduction of soil available P from 84 to 59 ppm at 0-30 cm depth and 24 to 13 ppm at 30-60 cm depth in the coconut basins. Neither a reduction in soil available phosphorus nor an increase consequent to fertiliser application at two levels for the past six years has significantly influenced foliar P levels and yield. The possibility of skipping application of phosphatic fertilisers to adult coconut groves in soil where available P is around 24 ppm at 30 to 60 cm depth is outlined. The usefulness of foliar P levels as a guide to fertiliser application seems to be doubtful.