Integrated Approaches to Soybean Seed Health Management: Effects of Bio-agents, Fungicides, and Hot-Water Treatment

Abstract

Soybean (Glycine max (L.) Merr.) seed health and seedling vigour are important determinants of successful crop establishment. The present study evaluated biological and chemical seed treatments for improving seedling vigour and assessed hot-water treatment for reducing seed-associated mycoflora in six soybean varieties. Five biological agents, namely Trichoderma viride, Trichoderma harzianum, Pseudomonas fluorescens, Bacillus subtilis, and phosphate-solubilizing bacteria (PSB), and six fungicides were evaluated under pot conditions. Seedling vigour index was assessed 21 days after sowing. Hot-water treatment at 50°C for 10 min was evaluated using the blotter method, with fungal growth and germination assessed after incubation. Among the biological agents, Trichoderma viride recorded the highest mean increase in seedling vigour index over the untreated control (61.31%), followed by Trichoderma harzianum (57.85%). Among the fungicides, copper hydroxide produced the highest mean increase (52.98%), followed by copper oxychloride (47.25%). Treatment responses varied among soybean varieties, indicating differences in treatment compatibility. Hot-water treatment reduced the reported cumulative frequency of seed-associated mycoflora from 586.86 to 366.57, representing a numerical reduction of 37.54%. CG Soya-1 recorded the highest germination after hot-water treatment (90.00%) and the lowest reported fungal frequency (46.65). These findings identify promising seed-treatment approaches for improving soybean seedling vigour and seed health under the experimental conditions.