Biocontrol Evaluation and Benefits in Controlling Southern Blight in Pepper and Hemp

Mustapha Ọláwuni, Tennessee State University


Southern blight disease caused by Sclerotia rolfsii is an economically important disease in pepper (Capsicum annuum L.) and hemp (Cannabis sativa L.) production in southeastern United States. Conducive environmental conditions for the disease include high temperatures of 30°C, pH 6.5, alternate light and darkness cycles of 12 hours. Southeastern United States, tropics and subtropic regions have favorable environment for this disease for growth and survival of resting structures allow the pathogen to survive long periods in soil. This disease is one of the problems facing industrial hemp production. Endophytes are known for symbiotic relationships with their hosts and occupy the same ecological niche as phytopathogens. Bacterial endophytes IMC8 (Bacillus thuringiensis), PRT (Bacillus subtilis) PSL (Bacillus amyloliquefaciens) and twelve other unidentified endophytes including two isolated from hemp (Hemp-1 and Hemp-2), were evaluated for potential in biocontrol of southern blight using laboratory bioassay dual cultures technique. Isolates IMC8, PRT, PSL Hemp-1 and Hemp-2 were evaluated for plant growth promotion and southern blight disease severity in hemp and pepper using pathogen infested soil in greenhouse and field. Results on laboratory assays showed that several endophytes including PSL, PRT, IMC-8, Hemp-1, and Hemp-2 significantly inhibited growth of Sclerotium rolfsii and exhibited great potential as biological control agents for southern blight disease management. Greenhouse and field studies showed PSL, PRT, IMC-8, Hemp-1, and Hemp-2 promoted hemp and sweet pepper plant growth and treated plants grown in soil infested with Sclerotium rolfsii in greenhouse and in field displayed growth promotion and reduced southern blight disease severity.

Subject Area

Pathology|Agriculture|Plant sciences|Microbiology

Recommended Citation

Mustapha Ọláwuni, "Biocontrol Evaluation and Benefits in Controlling Southern Blight in Pepper and Hemp" (2023). ETD Collection for Tennessee State University. Paper AAI30693532.