Effect of Water Deficit at Different Growth Phases of Peanut. II. Response to Drought During Preflowering Phase

Abstract

Abstract Water deficits can affect peanut yields differentially depending on time of occurrence and intensity. Previous reports have shown that moderate water deficit during the preflowering phase increases pod yields by 13 to 19% relative to the fully irrigated control. This paper describes, in a more quantitative way, crop physiological factors that contribute to these increased yields. In the 1980 to 1981 and 1981 to 1982 postrainy seasons, a study was conducted on a medium deep Alfisol at the International Crop Research Institute for the Semi‐Arid Tropics (ICRISAT) in central India, to examine the responses of peanut ( Arachis hypogaea L.), cv. Robut 33‐1, under three levels of soil water deficits during preflowering phase relative to an adequately irrigated control. Three intensities of drought were created (from 10–50 d after sowing [DAS]) using‐line source sprinkler irrigation, while the control was irrigated at 10‐d intervals. Moderate water deficits during the preflowering phase increased subsequent crop growth and pod growth rates in 1980 to 1981 but not in 1981 to 1982. Differences in flowering and total pod numbers between treatments were relatively small when compared to the subsequent differences in pod setting and maturity. In both seasons, greater synchrony of pod set in the moderately stressed plots resulted in a greater proportion of mature pods at final harvest. The most severely stressed plot had lower yields despite adequate irrigation subsequent to the preflowering water deficits.