Nutrient uptakes and their contributions to yield in peanut genotypes with diferent levels of terminal drought resistance

Abstract

Diferent peanut yields under terminal drought might be due to the diferent nutrient uptakes among peanut genotypes.Nutrient uptake was presumed to be a drought-resistant trait and might involve drought tolerance mechanisms. Te aims of this study,therefore, were to characterize the efect of terminal drought on peanut nutrient uptake and to investigate the genotypic variabilityof nutrient uptake and its interactions with terminal drought. Field experiments were conducted at the Field Crop Research Stationof Khon Kaen University, Khon Kaen, Tailand, from October 2010 to January 2011 and October 2011 to January 2012. Six peanutgenotypes were tested under well-watered and terminal drought conditions. Data were recorded for N, P, K, Ca, and Mg uptake andbiomass (BM) and pod yield (PY); the ratio of nutrient uptake under stress condition was calculated. Terminal drought signifcantlyreduced nutrient uptake in both years, and peanut genotypes difered considerably with respect to nutrient uptakes under well-wateredand terminal drought conditions. ICGV 98324 and ICGV 98348 were the best genotypes for nutrient uptake under terminal drought.Tainan 9 and Tifon 8 had low nutrient uptake under both conditions. ICGV 98308 and Tifon 8 had medium uptake and Tainan 9 hadthe lowest. Signifcant correlations between nutrient uptakes and BM and PY were mostly observed under well-watered and droughtconditions. Based on nutrient uptake, ICGV 98324 and ICGV 98348 were identifed as drought-tolerant lines. Tese genotypes couldmaintain high nutrient uptakes across water regimes; consequently, these traits can also be used as efcient tools for selecting peanutgenotypes with terminal drought tolerance.