Antifungal activity of Boerhavia diffusa L. extract against Phytophthora spp. in tomato and pepper

Abstract

Antifungal properties of Boerhavia diffusa L. (Nyctaginaceae) methanolic extract have been investigated against Phytophthora infestans and Phytophthora capsici, causal agents of late blight disease in tomato and pepper, respectively. The minimum inhibitory concentration of B. diffusa extract was 0.25 % for P. infestans and 0.5 % for P. capsici. The extract had fungitoxic effect on P. infestans and completely inhibited its mycelial growth at all tested concentrations (0.25, 0.5, and 1 %). P. capsici mycelial growth was inhibited of 90 % by the 1 % extract after five days of culture. B. diffusa extract, at the concentration of 0.25 % significantly reduced P. infestans disease symptoms also in young tomato plants. The plant extract significantly reduced disease symptoms of P. capsici in young pepper plants at all tested concentrations (0.25, 0.5, and 1 %). The efficacy of B. diffusa extract against P. capsici increased with the increasing extract concentration and decreased over time. The 1 % concentration showed the best efficacy in controlling this oomycete. As its effect was comparable to that of the synthetic fungicide, B. diffusa extract can be considered as a potential environmentally friendly alternative to chemical control of late blight in tomato and pepper.