Varietal differences in wheat yield and phosphorus use efficiency as influenced by method of phosphorus application

Wheat varieties respond differently to phosphorus fertilization. Method of P application may influence the degree of responsiveness. Three varieties of wheat viz. Punjab-96, Inqelab-91 and Pasban-90 were grown after applying Nitrophos (23:23) @ 0 or 44 kg P ha-1 by two methods, (i) broadcast and incorporation at sowing and (ii) fertigation at first irrigation. Grain yield and total P uptake data obtained after crop harvest showed that wheat varieties differed significantly in grain and straw yield, harvest index and 1000- grain weight. Application of P by either method increased grain and straw yield as well as total P uptake over control. Method x P interaction effect was also significant for yield, indicating higher yield response due to fertigation compared to broadcast method of P application. Where P was applied by fertigation grain yield, total P uptake, agronomic and P fertilizer efficiency were all higher in cv. Inqelab-91 compared to cv. Pasban- 90. Thus application of phosphatic fertilizer by fertigation along with selection of an appropriate variety may contribute to improve P fertilizer efficiency and increase wheat grain yield.