IN-VITRO ACTION OF PLANT EXTRACTS ON COLLETOTRICHUM ACUTATUM, ALTERNARIA SOLANI AND SCLEROTIUM ROLFSII

ABSTRACT

The use of fungicides is, in many cases, the only efficient and viable measure for controlling diseases and guaranteeing the sustainability of agricultural activity. On the other hand, it is also a technology that brings negative impacts to the environment and public health. The fungi Anternaria solani and Colletotrichum acutatum cause serious damages to the tomato and strawberry productions, respectively. Sclerotium rolfsii is a soil pathogen, capable of provoking severe damages to several agricultural species. The present work was aimed at evaluating the action of ethanolic and hexanic extracts of 8 vegetable species on the: a) inhibition of the mycelial growth of these phytopathogens, b) inhibition of the conidial germination (A. solani and C. acutatum) and c) inhibition of the sclerotial germination of S. rolfsii. The hexanic extracts of Ruta graveolens, Allamanda cathartica, Impatiens walleriana, Allium sativum and Lavandula augustifolia were the ones that provided the smallest values of mycelial growth of the 3 pathogens. The hexanic extract of A. sativum was the only one that inhibited the conidial germination of A. solani. The hexanic extracts of I. walleriana, A. sativum and L. augustifolia were the only ones that led to the total absence of conidial germination of C. acutatum. The hexanic extracts of R. graveolensand I. walleriana totally inhibited the sclerotial germination of S. rolfsii.

KEY WORDS Alternative control; anthracnose; early blight; Sclerotium root rot