Foliar application of potassium at different pheno-phases subjected to water deficit levels improved yield and yield attributes of wheat

Water stress at critical growth stages diminishes the wheat production and has harmful effect on crop growth and development, however regulated water deficit and potassium foliar application ameliorates its adverse effect up to a certain extent. Screen house study was conducted in Complete Randomized Design (CRD) having four repeats. Varieties of wheat i.e. Lalma (drought resistant) and Pakhtunkhwa-2015 (drought susceptible), water stresses i.e. mild water stress (50 % of water required for field capacity) and severe stress (no application of water) at different growth stages of the crop and potassium (K) foliar spray (1%) including control (no stress + no spray) were the treatments. Results showed that application of potassium spray at three critical stages mitigated the adverse effects of both stress levels. Potassium foliar application at grain filling stage stress of the crop showed maximum increase in plant height (76.3 cm), spike length (10.1 cm), grains per spike (53), spikelet per spike (18), grains weight (3.87g), biomass yield (4.70 g plant(-1)), grain yield (1.99 g plant(-1)), harvest index (42 %) and water balance of the plants in terms of relative water contents (RWC) of the wheat crop. Among varieties Lalma has produced maximum grains spike(-1) (54.2), hundred seeds weight (3.94 g), biomass yield (4.88 g plant(-1)) and grain yield (2.01 g plant(-1)) as compared to Pakhtunkhwa-2015. It is concluded that application of foliar potassium decreases the adverse effect of water stress at any growth stage, although grain filling stage was found more sensitive.