Effect of Different Phosphorus Levels on Growth and Yield of Wheat under Water Stress Conditions

Water stress and low phosphorus availability are the limiting factors for growth and yield of wheat. Five different phosphorus levels (P = 0, 30, 60, 90, 120 kg ha-1) with three water stress levels (I1 = well-irrigated, I2 = water stress at reproductive stage and I3 = water stress both at vegetative + reproductive stages) were applied to check their effects on growth and yield of wheat. Higher application of phosphorus with optimum irrigation showed significant effect on growth of wheat. Higher phosphorus application rate compensate the effect of water stress conditions both at vegetative and reproductive stages. Drought stress at vegetative + reproductive stages was more drastically affected as compared to stress at reproductive stage. Lower phosphorus application rate with water stress caused maximum reduction in plant height, number of tillers, spike length, number of grains spike-1, 1000 grains weight, grain yield and straw yield. It was concluded that application of phosphorus at higher rate could compensate drastic effect of water stress. On overall performance, application of phosphorus at the rate of 120 kg ha-1 showed better results under water stress conditions as compared to other phosphorus levels. Keywords: - wheat, water stress, phosphorus, growth, yield