Potassium applied under drought improves physiological and nutrient uptake performances of wheat (Triticum Aestivun L.)

The physiological and nutrient uptake performance of two wheat (Triticum aestivum L.) cultivars (Lasani-2008 and Auqab-2000) to foliar application of 1% potassium (K) at three different growth stages (tillering, flower initiation and grain filling) was investigated under water limited environment in a wire house experiment at the Nuclear Institute for Agriculture and Biology, Faisalabad.The aim was to find out the best K application stage for improvement in drought tolerance potential.Drought stress was created by withholding irrigation at the three growth stages and then K was sprayed with carboxymethyl cellulose as a sticking agent, whereas Tween-20 was used as a surfactant for foliar spray.At maturity, aboveground nitrogen, phosphorus, K, sodium and calcium uptakes by the crop were measured.Besides, water potential, osmotic potential and turgor potential of crop were also estimated.The results indicated that the drought stress at all three critical growth stages of wheat adversely affected plant's nutrient uptake, water potential, osmotic potential and turgor potential of wheat plants.The exogenous application of K under drought stress at all three critical growth stages enhanced tolerance of wheat by reducing toxic nutrient's uptake and improving the physiological efficiency.In this regards, both varieties showed uniform behavior.Maximum improvement in all the recorded nutrients uptake and physiological parameters was achieved when K was applied at grain filling stage of both cultivars.