Abstract

The aim of this investigation was to isolate the most specific, effective and competitive strains for peanut, and to determine the level of variability in peanut cultivars response toward single/dual inoculation. Peanut seeds of three cultivars namely 55–437, Fleur 11 and 69–101 were inoculated with two bradyrhizobial strains (LMG9283 and USDA3187) and an AM fungus Glomus intraradices, individually or in combination, and were grown in the open–air conditions using a non–sterile sandy soil from Sangalkam. Plant controls were supplied with NPK chemical fertilizer at the rate of 150 and 300 kg ha^–1. Results obtained in term of nodule occupancy revealed a high competitiveness of LMG9283 strain with cultivars 55–437 and 69–101. However Fleur 11 cultivar was nodulated by indigenous strains rather than the introduced strains. Assessment of the data on nodulation, shoot biomass and pods yield revealed that, among the single inoculation of the three cultivars, 55–437 and 69–101 produced the largest increase in the parameters studied, however, Fleur 11 showed a higher growth and pods yield with the chemical fertilization. The dual inoculation with bradyrhizobial strains associated with G. intraradices further improved the parameters studied for 55–437 and 69–101, demonstrating a synergy between LMG9283 and G. intraradices. This better response allowed us to suggest that 55–437 and 69–101 cultivars should be tested in the arable fields with Bradyrhizobium strain LMG9283 and G. intraradices.

Key words: Arachis hypogaea L., Bradyrhizobium strains, Glomus intraradices, yield, inoculation.