Response of pigeon pea (Cajanus cajan L. Millsp.) genotypes to Rhizobium inoculation and phosphorus fertilizer application

Abstract

A study was initiated to determine if there are genotypic differences in the nitrogen-fixing ability of local and exotic pigeon pea genotypes, and to determine their response to inoculation with Rhizobium strains. Twelve pigeon pea genotypes from different maturity groups were inoculated with two Rhizobium strains and grown in soils with and without phosphate fertilizer at Thika, Kenya in 1984. Inoculation increased the number of primary branches, reduced the time to flowering and maturity, and increased nodulation and grain yield. Inoculation increased plant height in the late maturity group but reduced it in the medium and early maturity genotypes. Significant genotype X inoculation interaction was detected for number of primary branches, nodules/plant and the 100-seed weight. The results also indicated that the response to a given Rhizobium strain is genotype specific. Cultivars NPP670 and NPP 671/1 showed improved performances when inoculated with strain P724 while NPP673/3 performed better with strain P791.