Antifungal activity of foliar extracts from Maytenus spp. on Cylindrocladium clavatum

Abstract

The use of leaf extracts to reduce pesticide applications that harm the environment and cause environmental disorder can be an alternative to the control of fungi during propagation of eucalyptus. The experiment tested the effect of leaf extracts from two species of espinheira-santa on Cylindrocladium clavatum. The extraction of plant material was carried out through percolation at 28 °C for 7 days using column liquid chromatography with hexane, chloroform, and methanol as solvents. Evaluations of antifungal activity were performed with a fixed extract concentration of 2,000 mg L-1. The minimum inhibitory concentration of the extracts, sporulation, and control of C. clavatum in eucalyptus leaves were evaluated using concentrations of 500, 250, 125, and 100 mg L-1 after 5 and 15 days of incubation. The concentration of 500 mg L-1 of chloroform extract from leaves of M.ilicifolia and M.aquifolium resulted in a better control of Cylindrocladium clavatum. In the evaluation of sporulation, the crude and methanolic extracts obtained the best performances, with emphasis on the concentrations of 500 and 250 mg L-1, which resulted in the lowest number of spores. For the evaluation of the minimum inhibitory concentration, it was observed that the fungus is not 100% controlled, but that the greatest effect lies on the reduction of fungus growth. In the image tests with eucalyptus leaves, the crude extract resulted in the smallest lesion area at concentrations of 500 and 250 mg L-1. The extract was more effective when applied in its raw form and with greater concentration.