Effect of Water Deficit at Different Growth Phases of Peanut. I. Yield Responses¹

Abstract

Abstract The response of a peanut ( Arachis hypogaea L.) cultivar Robut 33‐1 to drought stress imposed at different growth stages was studied during the post‐rainy seasons of 1980–1981 and 1981–1982 on a medium deep Alfisol at ICRISAT Center, India. Irrigation amount was varied to three levels for each of the following phases: (i) emergence to maturity, (ii) emergence to the start of peg initiation, (iii) from the start of flowering to the start of seed growth, and (iv) from the start of seed growth to maturity. The amount of water applied (stress intensities) during these phases was varied using line‐source irrigation, but the crops otherwise were irrigated uniformly at regular intervals. The greatest reduction in kernel yield occurred when stress was imposed during the seed‐filling phase. Decreased irrigation during the early phase increased the pod yield relative to the fully irrigated control treatment by 19% during the 1980–1981 and by 13% during the 1981–1982 growing seasons. Lowest pod yields resulted from severe stress from emergence to maturity. The evapotranspiration‐yield relationships showed a strong interaction with timing of drought.