Influence of spacing and irrigation on the seed yield of a CMS line ‘ICPA 2043’ of hybrid pigeonpea

Abstract

The study was undertaken to develop a package of agronomic practices for large-scale nucleus seed production of a cytoplasmic-nuclearmale-sterile(CMS)line ‘ICPA2043’.The experimental treatments included two planting ratios involving 4 male-sterile: 1 male-fertile and 3 male-sterile: 1 male-fertile lines, two irrigation frequencies (14 and 18 day intervals), and eight plant spacings. Spacing of 75 cm × 30 cm in the 3:1 row ratio with irrigation at 14 days interval during reproductive period produced the highest seed yield of 1871 kg/ha, which was 18.30% more than the best seed yield (1529 kg/ha) obtained in the 4:1 planting ratio with spacing of 75 cm × 30 cm and irrigation at every 14 days. The results further showed that for 4:1 and 3:1 planting ratios, the yield in 75 cm row spacing was 42.64 and 45.56% greater, respectively than the 150 cm with irrigation at every 14 days. Under low plant population density, plants were shorter and sturdier with semi-spreading branches and produced greater single plant yield, biomass, number of primary branches, and pods/plant due to better availability of light. These attributes, however, did not help in realizing high seed yield per unit of land area. In contrast, under high plant population density, individual plants were tall with erect branches, had relatively less biomass and seed yield per plant but produced significantly higher seed yield per ha