Biocontrol Potential of Entomopathogenic Fungus Beauveria Bassiana Against Cotton Damping-Off

Abstract

Seedling damping-off causes significant yield losses in cotton worldwide. Fungicide use is not always effective and can increase disease resistance, environmental contamination, health risks, and production costs. Beauveria bassiana is an entomopathogenic fungus with potential for plant disease control. This study evaluated the biocontrol effect of B. bassiana strains on emergence, pre- and post-emergence damping-off, and disease index of Sezener 76, Acala Maxxa, and Lachata cotton cultivars against Rhizoctonia solani AG4 and Fusarium sp. under in vivo conditions. All B. bassiana strains significantly affected emergence, damping-off, and disease index across the three cotton cultivars. Beauveria bassiana strains were most effective against cotton damping-off in the tolerant Sezener 76 cultivar. The highest emergence against R. solani AG4 was recorded in the Sezener 76 cultivar treated with B. bassiana Bb1. The B. bassiana Bb1 showed the best effect against pre-emergence damping-off caused by Fusarium sp. in the Sezener 76 cultivar. The lowest post-emergence damping-off rates against R. solani AG4 were obtained from the positive control and B. bassiana Bb1 treatments in Acala Maxxa and Lachata cultivars. Disease index values for all varieties and treatments ranged from 1.7 to 3.0 compared with the negative control. All B. bassiana strains showed disease index values similar to positive control against both pathogens. Consequently, B. bassiana Bb1 could be used as an alternative biofungicide for control of the cotton damping-off disease. Detailed studies are needed on disease control in field conditions with this strain.