Optimization of fertilizer doses and plant population in summer irrigated groundnut (Arachis hypogaea)

To stabilize the productivity of summer groundnut (Arachis hypogaea), optimization of plant spacing and fertilizer levels is imperative. A field experiment was conducted at Coconut Research Station, Aliyarnagar during 2013-14 with three plant populations (P1 - 30 x 10 cm, P2 - 25 x 10 cm and P3 - 20 x 10 cm) and graded nutrient levels (F1- 75 %, F2 - 100 % and F3 -125 % RDN) in TMV 13 groundnut variety to bring out the effect of plant geometry and fertilizer levels on the system productivity and economic returns, in split plot design with each of the above treatments replicated thrice. Of the different spacings adopted, P1 - plant population @ 3.33 lakhs per ha (30 x 10) cm recorded significantly higher kernel yield (2332 kg ha-1) followed by P2 - plant population @ 4.0 lakhs per ha (25 x 10) cm) whilst dry haulm yield although higher in P1 (2935 kg ha-1) did not attain statistical significance. The dry pod yield (2787 kg ha-1), net returns (Rs. 68696 ha-1) and benefit cost ratio (2.36) were higher in P1 followed by P2. As a natural corollary, plant stand was higher in P3 with a plant population of 5.0 lakhs per ha (20 x 10 cm) followed by P2. The number of branches, total number of pods per plant and harvest index were statistically superior with wider spacing (P1) compared to the other spacings adopted. The percentage of sound matured kernels was higher in P2 followed by P1. Other parameters viz., plant height, shelling out–turn remained unaltered with respect to the different spacings adopted. Application of 100 % RDN (F2) was significantly superior over rest of the treatments (F1 and F3) with regard to kernel yield. F2 and F3 showed statistical superiority and parlance in majority of growth parameters, yield attributes and economics. Plant population of 3.33 lakhs per ha (30 x 10) cm along with application of 100 %RDN (25 – 50 – 75 NPK kg ha-1) proved its superiority in kernel yield and economic returns.