Control of powdery mildew (Leveillula taurica) using Trichoderma asperellum and Metarhizium anisopliae in different pepper types

Abstract

This study investigated the effectiveness of Trichoderma asperellum (Samuels, Lieckf. & Nirenberg) and Metarhizium anisopliae (Metschn.) Sorokin in controlling pepper powdery mildew. Culture extracts of these fungi inhibited conidial germination in Leveillula taurica (Lev.) G. Arnaud. T. asperellum showed higher chitinolytic activity than that of M. anisopliae. The latter exhibited elevated β-1,3-glucanase activity as compared with that of T. asperellum. In a high-tunnel greenhouse, T. asperellum was more persistent than M. anisopliae. Jalapeno pepper was more vulnerable to powdery mildew than arbol pepper. In the field, the fungi did not control powdery mildew in jalapeno pepper. In arbol pepper, both fungal species reduced disease severity to a level similar to that of a chemical control. T. asperellum and M. anisopliae may be effective in the control of powdery mildew on peppers and could lead to the disuse of pesticides on some but not all types of pepper.