Does phosphite, a reduced form of phosphate contribute to phosphorus nutrition in corn (Zea mays L.)?

Abstract

Although fungicidal properties of phosphite have been recognized, its use as a fertilizer-P is still being debated. The objective of this study was to evaluate the effect of foliar-applied phosphite (HPO₃⁻²) on the growth and yield of corn (Zea mays L.). Traditional fertilizer-P was also applied to compare the efficacy of phosphite. Dry matter yield, grain yield, and tissue P concentrations (grain, leaf, and stem) were evaluated in two field and two greenhouse studies in Oklahoma for 2 years. A commercial phosphite solution which contains 200 g P kg⁻¹ was sprayed at the rate of 2.34 L ha⁻¹ at different growth stages. Foliar phosphite did not increase dry matter and grain yield. In general, P concentrations in the grain, leaf, and stem were unaffected regardless of number of applications. Farmers should take with caution while using phosphite as a fertilizer to correct P deficiency for corn production.

Keywords:

• phosphite
• phosphorus
• corn