Potassium fertilization mitigates the adverse efects of drought on selected Zea mays cultivars

Abstract

In the present study, the role of potassium (K) in mitigating the adverse efects of drought stress (DS) on 2 maize (Zea maysL.) cultivars, Shaandan 9 (S9; drought-tolerant) and Shaandan 911 (S911 ; drought-sensitive), was assessed. K application increaseddry matter (DM) across all growth stages and grain yield (GY) in both cultivars under DS, but not under control conditions. Drought-tolerant cultivar S 9 was superior to drought-sensitive cultivar S 911 under DS in terms of DM and GY regardless of K addition. Additionally,K application increased relative water content, nitrate reductase activity, and concentrations of potassium ion, free proline, solubleprotein, and endogenous glycine betaine in both cultivars. Tese positive efects due to K fertilization under DS were greater for S 911than for S 9. In contrast, the diferences in the above parameters between K-treated plants and plants under control conditions were eithernonsignifcant or marginal. Tis study provides direct evidence of the benefcial physiological function of K fertilization in mitigatingthe adverse efects of DS by increased nitrate assimilation and osmotic regulation, but not due to its nutritive role.