Nutrient uptake and nutrient use efficiency of Valencia peanut genotypes with different levels of drought tolerance under terminal drought

Selection of suitable peanut genotypes with resistance to drought is an important strategy to combat problems of drought. This study aimed to investigate nutrient uptake and nutrient use efficiencies of Valencia peanut genotypes in response to terminal drought. A pot experiment was conducted in a factorial randomized complete block design with 4 replications. Factor A consisted of two soil water regimes (field capacity and 1/3 available water), and ten Valencia peanut genotypes were assigned as factor B. Macronutrient uptakes and nutrient use efficiencies (NUE) were examined; drought reduced nutrient uptakes, NUE for biomass and NUE for pod yield. Unique behaviors of some tested Valencia peanut genotypes on given traits were found. Genotype PI536121 had the highest K, Ca and Mg uptakes, while two genotypes ICG10890 and ICG10092 showed the highest NUE for biomass and pod yield. Genotype ICG14127 performed well regarding K, Ca and Mg uptakes and NUE for pod yield. Total nutrient uptakes of N, P, K, Ca and Mg were significantly positively correlated with biomass and pod yield (r = 0.48**-0.76**), whereas the number of seeds per pod and 100-seed weight were positively correlated with total nutrient uptakes of N, K, Ca and Mg (r = 0.23*-0.47**). Three tested genotypes ICG10092, ICG10890 and ICG14127 are promising genetic sources for further improvements of Valencia peanuts for drought tolerance.