Effect of Water Regimes on the Growth of and Yield of Rabi / Summer Groundnut Genotypes in Northern Transition Zone of Karnataka

Background: Groundnut crop grown during Rabi / summer experiences moisture stress, thus irrigation is must. However, water for irrigation gets scarce during summer month hence it becomes important to choose stress tolerant varieties and optimize irrigation schedule without compromising the yield.
Methods: A field experiment with four rabi / summer groundnut genotypes (G₁: Dh-86, G₂: Dh-101, G₃: K-9 and G₄: G2-52) exposed to four irrigation regimes (I₁: 7 irrigations at 15 days interval from sowing to 105 DAS as control, I₂: withdrawal of one irrigation between 45 - 60 DAS i.e., pegging stage, I₃: withdrawal of two irrigations between 45-75 DAS i.e., at pegging and pod filling stage, I₄: withdrawal of four irrigations from 45-105 DAS i.e., at pegging, pod filling and kernel development stage) was carried out from December to April of 2016-17 on black cotton soils at AICRP on Groundnut UAS, Dharwad.
Result: Among the genotypes tested, Dh-86 recorded significantly higher pod yield (2,376 kg ha^-1) followed by Dh-101 (2,215 kg ha^-1) and K-9 (2,048 kg ha^-1), whereas G2-52 gave the lowest yield (1,880kg ha^-1) and all of them performed well at I₁ and I₂ irrigation regimes. Among different water regimes, I₁ (i.e., control) recorded significantly taller plants, higher LAI, more branches and higher dry matter at harvest as compared to other irrigation regimes, hence it also recorded significantly higher pod yield and haulm yield (2,870 and 4,691 kg ha^-1, respectively), but was found at par with I₂, i.e., crop stressed only at pegging stage (2,858 and 4,648 kg ha^-1, respectively). This suggests that, at the most, one irrigation can be skipped at pegging stage without compromising on yield.