International Journal of Environment and Climate Change

Charcoal rot (Macrophomina phaseolina) causes high grain yield loss in major soybean-growing nations worldwide. The present study aimed to reveal the effect of stage-wise charcoal rot incidence and their root and stem severity index on the yield criteria of soybean varieties. Additionally, an attempt was made to derive integrated management practices and their influence on seed quality. All the twelve varieties were affected by charcoal rot, and its incidence and root and stem severity index were high in Shivalik (48.5% and 3.7, respectively). In yield estimation, the percentage of yield loss ranged from 8.7% (JS 20-98) to 53.9% (Shivalik). Percent yield loss had a strong significant positive relation with percent incidence (0.912**) and Root and Stem severity index (0.813**) of charcoal rot. Seed treatment of Penflufen 13.28% + Trifloxystrobin 13.28 % FS @ 1ml/kg followed by spraying of tebuconazole 25% EC @ 0.1 % spraying at 45,60,75 days was significantly superior in reducing charcoal rot (19.7%) in comparison to untreated (37.3%). The highest seed germination (80.0 %) and least association with M. phaseolina (13.33%), Aspergillus flavus (3.33%), Fusarium sp., (13.34%) in comparison to control (50, 36.67, 23.33 and 36.67 %, respectively) were also resulted from the seed obtained from above treatment. In bioagent, seed treatment of T. harzianum @ 10 gm/kg followed by foliar spray of tebuconazole 25% EC @ 0.1% at 45,60,75 days was the second-best combination among all treatments in all respects. The effect of these fungicides and bio agents as seed treatment also improved the number of branches, pods, 100 seed weight and yield. Hence, these combinations could be applied to minimize charcoal rot and yield losses in soybean.