Atividade antifúngica de extratos das folhas de Solanum lycocarpum St. Hr Still sobre fungos fitopatogênicos

Abstract

The use of plant extracts in the control of phytopathogenic fungi has increased significantly, mainly because of pesticides are costly to the producer and the damage caused to the environment. The lobeira (Solanum Lycocarpum St. Hill.) is largely used to control diseases caused to man thus highlighting their fungicide potential before the other fungi of agricultural interest. The aim of this study was to evaluate the fungitoxic action of methanol extract and hydromethanolic leaves of lobeira in the control of the Didymella bryoniae and Curvularia spp. fungi. Solvents were used with different concentrations, application forms of these solvents were distributed and spread among culture medium and application rates of 0, 10, 20, 30, 40, and 50 added among the culture medium and foliar application into plantlets. Daily evaluations were performed for mycelial growth of fungi and mortality of watermelon plantlets, as for the evaluation of sweet corn plantlets evaluations were performed every 48 hours after inoculation of the fungus. Both experiments were installed in a completely randomized design, and for the in vitro test factorial 2 x 5 x 2 (extract concentration, dose, method of application) and the in vivo test in factorial 2 x 5 (concentration, extract and doses). The data were submitted to the variance and regression analysis. For the in vitro test it was observed that for D. bryoniae crude extract 50 dose was the best inhibited the mycelial growth of the fungi. For Curvularia spp. the dose was indifferent mycelial growth but the extract was spread to the culture medium decreased its development. For the in vivo test, the highest efficiency in the control of diseases to the crude extract was 30μL and the aqueous extract 50 to Curvularia spp. and to D. bryoniae the crude extract to 10 and the aqueous extract to 20 .