In recent years Macrophomina stem blight and dry root rot diseases have become major constraints in successful and profitable cultivation of pigeonpea caused by Macrophomina phaseolina (Tassi) Goid. Increasing dry spells and droughts during pigeonpea cultivation has widen the scop for infection and spread of these diseases very rapidly than ever. There are no resistant cultivars available for cultivation among the cultivated gene pool. In such cases, suitable management become very essential. In absence of host resistance, the efficacy of different fungicides and bioagents was evaluated in field during kharif-2022 for management of both stem blight and dry root diseases. Among the tested treatments, T9 consisting of seed treatment, soil drenching and foliar spray with Trichoderma asperellum + Pseudomonas fluroscence (5gm/kg, 5gm/lit) recorded significantly lowest mean disease incidence (2.77 %) followed by T4, ST + foliar spray and drenching with Carbendazim 12WP + Mancozeb 63WP (5.85 %) whereas, T8 (ST + foliar spray and drenching with Carbendazim 50WP)and T6 (ST + foliar spray and drenching with Thiophanate methyl 70WP) recorded on par mean disease incidence. Maximum per cent disease incidence was observed in untreated control (34.39 %) followed by T2, ST + foliar spray and drenching with copper oxychloride 50WP (19.13 %) plot. Benefit cost ratio was derived for the treatments evaluated and results revealed that highest BCR was observed in T9 (2.24) followed by T4 (1.90). Lowest benefit cost was obtained from T5 (0.12) followed by control (0.18). After calculating the benefit-cost ratio for each of the treatments under consideration, the findings showed that T9 had the greatest BCR (2.24), followed by T4 (1.90), while T5 had the lowest benefit cost (0.12), with control coming in second (0.18).

Bio-controls, fungicides, Macrophomina stem blight, Dry root rot, Disease management

The findings of the present study are very promising in reducing the wilt incidence caused by stem blight and dry root rot. The seed treatment with biocontrol agents protected the seeds against fungal pathogen infections during seed germination and seedling stage. Further foliar spray of biocontrol agents prevented the fresh infections by the target pathogens on stem and on roots until the crop is harvested.

Rahul Gadde, Mallikarjun Kenganal, Gururaj, S., Yenjerappa S.T. and Muniswamy S. (2023). Management of Macrophomina stem blight and dry root rot diseases in pigeonpea caused by Macrophomina phaseolina (Tassi) Goid. Biological Forum – An International Journal, 15(11): 581-585.