The effect of potash on grain yield, protein, and essential amino acid composition of wheat cultivar, 'Mexi-Pak-65' was studied under irrigated conditions of N.W.F.P., Peshawar. Potash @ 0, 20, 40, 80, 120 and 160 kg K2O/ha as potassium sulphate was applied before sowing. The yield and protein content of grain and protein production per unit area were significantly (P