Efficacy of plant extracts for anthracnose control in bell pepper fruits under controlled conditions

Anthracnose is an important disease of bell pepper (Capsicum annuum) in Brazil and worldwide. This research investigated the efficacy of plant extracts for control of this disease in bell pepper fruits caused by Colletotrichum acutatum under controlled conditions and analyzed the best treatments in relation to different extract and inoculum concentrations, pathogen isolates, and temperatures. In the preliminary screening, among aqueous or ethanolic extracts of 16 plant species evaluated, the best were 6% aqueous garlic, mallow, and ginger extracts, which reduced disease severity by more than 97%. Garlic extract required the highest concentrations to reduce severity by 75% (CL75) when compared to ginger and mallow extracts, but exhibited the best efficacy in relation to different inoculum concentrations and isolates of C. acutatum. It was also able to maintain greater than 90% efficacy at 20-30oC. The garlic aqueous extract effectively controlled anthracnose caused by C. acutatum in bell pepper fruits under controlled conditions.