Foliar Application of Phosphorus to Enhance Phosphorus Utilizationand Crop Growth: A Hydroponic Study

A hydroponic study was conducted to investigate the effectiveness of foliar applied phosphorus for enhancing P use efficiency and crop growth at Institute of Biotechnology and Genetic Engineering, The University of Agriculture, Peshawar. Wheat (cv. Atta Habib-2010) seeds were first germinated in sand culture and then three weeks old seedlings (7.5 cm) were transferred to water tubs containing Hoagland solution without P. The treatments included 0, 18, 36, 72, 144 and 216 mM as KH2PO4 solution foliarly applied three times with one week intervals starting after two weeks of seedlings transplantation. Each treatment unit consisted of 10 seedlings arranged in CR design with three replications. Plant height, shoot and root dry biomass of 6 weeks old seedling were significantly increased with each increment of foliar P suggesting effective absorption through leaf stomata and translocation to other parts of the plant body. The plant height, shoot and root dry biomass yield increased by 55, 40 and 35%, respectively, at 144 mM KH2PO4 solution over control. The shoot and root [P] as well as its total uptake by wheat seedlings also showed several times increase over control. Further increase beyond 144 mM KH2PO4 though did not show any adverse effect and was no better than lower P levels. It is concluded from the present study that [P] applied as foliar spray up to 144 mM KH2PO4 could be an effective way to enhance the plant growth in P deficient condition and application without any detrimental effect on wheat crop.