Effect of water deficit at different growth phases of peanut. I. Yield responses

Response of groundnut cv. Robut 33-1 to drought stress imposed at (a) emergence to maturity, (b) emergence to peg initiation, (c) from the start of flowering to the start of seed growth, and (d) from the start of seed growth to maturity was studied during the post-rainy seasons of 1980-81 and 1981-82. The amount of water applied during these phases was varied using line-source irrigation, but the crops otherwise were irrigated uniformly at regular intervals. The greatest reduction in seed yield (28-96%) occurred when stress was imposed during (d). Decreased irrigation during (b) increased pod yield relative to the fully irrigated control treatment by 19% in 1980-81 and 13% in 1981-82. The evapotranspiration-yield relationships showed a strong interaction with timing of drought