Effect of seed treatment with sodium hypochlorite and hot water on seed-borne fungi and germination of okra seed

Abstract

Abstract Effect of seed treatment with sodium hypochlorite (NaOCl) and hot water were investigated on the incidence of seed-borne fungi and germination of okra seeds. Seeds were treated with NaOCl solution maintaining the following treatments: 0.1% NaOCl solution for 3 min, 0.1% NaOCl solution for 5 min, 0.5% NaOCl solution for 3 min, 0.5% NaOCl solution for 5 min, 1% NaOCl solution for 3 min and 1% NaOCl solution for 5 min. In case of hot water, the treatments were 48°C for 10 min, 48°C for 12 min, 48°C for 15 min, 50°C for 10 min, 50°C for 12 min, 50°C for 15 min, 52°C for 10 min, 52°C for 12 min at 52°C for 15 min and control. Seed treatment with NaOCl and hot water reduced the seed-borne infection of Aspergillus spp., Fusarium spp., Macrophomina phaseolina, Colletotrichum dematium and Chaetomium spp. All the three concentrations of NaOCl decreased the prevalence of seed-borne fungi and increased seed germination. Higher concentration (1.0%) with longer period treatment (5 min) was the most effective for reducing fungal infection and increasing seed germination of okra. Hot water treatment at 48, 50 and 52°C for 10-15 min were effective to control the seed-borne infection of okra seed. However, higher temperature (52°C) with longer period (12-15 min) were more effective in reducing seed-borne infection. But seed treatment at 50°C for 12-15 min and at 52°C for 10-15 min negatively affected seed germination. Among the hot water treatments, seed soaking at 48°C for 12 min gave maximum germination (63%) compared to control (57%). Thus seed treatment with 1% NaOCl for 5 min or soaking seeds in hot water at 48°C for 12 min or 50°C for 10 min could be used for minimizing the incidence of seed-borne fungi and also hasten the germination of okra seeds.