Optimizing the plant spacing for the maximum yield of pigeon pea monoculture in Delta State of Nigeria

Abstract

Pigeon pea [Cajanus cajan (L.) Millsp.] is an important crop worldwide, usually sown in the mixed cropping system. However, the sole cropping system is constrained mainly by high weed infestation caused by under population and low productivity due to overcrowding.  It is necessary to optimize the appropriate crop spacing to fully maximize the potential of pigeon pea in a sole cropping system. In the 2019 and 2020 planting seasons, two varieties of Pigeon pea: ICP88038 and ICP6971 seeds planted at Ogbagu Ogume community communal farm settlement of Nigeria at three different spacing: 30 × 45, 30 × 60 and 45 × 45 cm at a seed rate of 7.41, 5.56 and 4.93 kg ha^-1, respectively. The experiment was a 2 by 3 factorial in a randomized complete block design with three replicates. The result showed that the 45 × 45 cm spacing produced significantly taller plants in 2019 (12.22±0.41) and 2020 (12.55±0.99), highest number of leaves in 2019 (11.50±0.67) and 2020 (9.83±0.96), number of pods in 2019 (138.33±12.01) and 2020 (153.17±23.43), dry pod weight in 2019 (3.57±0.27) and 2020 (3.76±0.39) and dry grain yield (t ha^-1) in 2019 (1.78±0.14) and 2020 (1.76±0.21). However, the genotypic effect on the parameters was insignificant.