Harnessing Plant Growth–Promoting and Wilt-Controlling Biopotential of a Consortium of Actinomycetes and Mycorrhizae in Pigeon Pea

Fusarium-induced wilt significantly affects the cultivation and yield of pigeon peas. This warrants sustainable disease management while promoting plant growth. The present study investigated the biopotential of coinoculation of Streptomyces pseudogriseolus S-9 and Rhizophagus irregularis for plant growth promotion and mitigation of the impact of Fusarium wilt on pigeon pea over three seasons at pot and field levels. Pigeon pea plants were subjected to Fusarium wilt stress and treated with different inoculation strategies, including single and combined applications of S. pseudogriseolus S-9 and R. irregularis. Plant growth parameters and yields were assessed to evaluate the efficacy of the coinoculation. In the pot experiment, T-6 treatment resulted in the longest root (62.56 ± 0.01 cm) and shoot (70.24 ± 0.01 cm) lengths compared to the application of commercial biofungicide T-8 (Trichoderma). This treatment also significantly influenced the yield of potted plants. It resulted in the highest fresh root weight (62.27 ± 0.01 g), fresh shoot weight (70.24 ± 0.02 g), maximum root (55.25 ± 0.01 g) and shoot dry weights (52.25 ± 0.01 g). In the field experiment, pigeon pea plants treated with the bioinoculant also demonstrated a substantial increase (р ≤ 0.05) in total grain yield, the weight of 100 grains, and the number of filled grains compared to the control group in all experimental seasons. In vitro, antagonism assay of compatibility of mycorrhizae and bacteria showed good activity using powder formulation. Thus, the consortium application inspired the broad application of Streptomyces and Trichoderma as effective bioinoculants for wilt management and yield improvement in pigeon peas.