Effect of fertilizer application through micro-irrigation technique on nutrient availability and coconut productivity

An investigation was conducted to study the response of drip fcrtigation in West Coast Tall variety of coconut for growth, nutrition, physiological parameters and yield at Central Plantation Crops Research Institute, Kasaragod during 1996·2008. The application of fertilizers either through drip fertigation or soil application resulted in significantly higher trunk height and girth at base than control (no fertilizer). However, no significant difference was observed among different dose offertigation and soil application treatments. The number ofleaves on the crown was significantly higher (32.6) under 75 per cent of NPK through drip fertigation which was on par with 50 per cent and 100 per cent NPK through drip fertigation and 100 per cent NPK through soil application and significantly differed from 25 per cent NPK through drip fertigation and control. Fertigation to coconut resulted in a marked increase in available nitrogen, phosphorus and potassium status in soil. Different levels of fertigation did influence significantly physiological parameters like net photosynthesis (PN)' transpiration (E) and stomatal conductance (gJ The treatment, 100 per cent NPK applied through fertigation resulted significantly higher PN' E and g, and which was on par with 50 per cent and 75 per cent thrpugh drip fertigation and significantly differed from 100 per cent NPK though soil application and control. Among the fertigation levels, coconut yield was significantly higher in 100 per cent NPK fertigation (131 nuts/palm/year) which was on par with 75 and 50 per cent NPK applied through drip irrigation and significantly differed from 100 per cent NPK through soil application, 25 per cent NPK through fertigation and control. The study indicated that adoption of fertigation increases the productivity with 50 per cent saving of chemical fertili zers which ensure the higher efficiency of nutrients in crop production.