Reponse of wheat (Triticum aestivum) to top-dressing of diammonium phosphate in rainfed areas of Shivalik foothills

A field experiment was carried out during 1997–98 and 1998–99 to find out the response of wheat (Triticum aestivum L. emend. Fiori & Paol) variety ‘PBW 175’ to top-dressing of diammonium phosphate (DAP) fertilier under rainfed Shivalik foothills of Jammu, Jammu and Kashmir. Basal application of recommended dose of DAP produced significantly taller plants, more number of effective tillers/m row length, ear length and number of grains/ear which ultimately increased the gram and straw yields. An adverse effect on the yield attributes and yield was observed with the delayed application of DAP from 10 to 50 days after sowing and the reduction in grain yield was from 3.9 to 26 1% and 3.5 to 28.9% during the first and second year respectively. However, the differences in yield attributes and yield with DAP application as basal and its top-dressing 10 DAS were at par The uptake of nutrients, viz. NPK was influenced significantly by the application of DAP at different intervals. Available phosphorus content in soil showed positive balance at the end of 2 years of experimentation.