Yield and Grade Response of Five Peanut Genotypes to Drought Stress At Different Stages.

Drought is a major factor in reducing productivity in peanut (Arachis hypogaea L.). There is a need to develop adaptive agricultural strategies for irrigation management, agronomic practices, improvement of drought-related traits through breeding selection, and development of transgenic crops with drought tolerance. The objectives of this study were to: 1) examine the main effects and interactions of five drought stress treatments (Full Irrigated, drought stress at 30 60, and 90 Days After Planting (DAP), and Non- Irrigated) on five peanut genotypes and 2) indentify the most and least drought tolerant genotypes to be used for further genetic study and breeding program. Five peanut genotypes (AP3, C76-16, A104, Georgia Green, 08T-12) were planted in split plot design, with irrigation treatment (main split) by genotype with three replications in 2010 and 2011. This project was completed using rain-out control shelters. Peanut yield and grade were determined and adjusted to 7 percent moisture. Yield and TSMK were significantly different for peanut genotypes both years. There was no yield interaction of irrigation treatment x genotype for either year, but there was an interaction for TSMK in 2011. T-test analysis indicated the greatest difference for yield and TSMK were for Irrigation Treatment (from 3272 to 5236 kg/ha and 0.71 to 0.75, respectively) and Genotype (ranging from 3874 to 4810 kg/ha and 0.70 to 0.76, respectively). The genotype with the best drought tolerance was ‘C76-16’ while ‘AP-3’ had the least drought tolerance. Comparison between irrigated and non-irrigated regimes showed that stress occurring at 60 DAP had the greatest effect on yield and TSMK followed by 90 and 30 DAP. These data imply that ‘C76-16’ could be used as a drought tolerant parental donor and drought stress treatment at 60 DAP could be used as screening tool in breeding programs.