Abstract

GARCIA M, Pedro J; CABRERA P, Samuel R; SANCHEZ, Jimmy J  and  PEREZ C, Alberto A. Evaluation of a biofungicide for the control of maize banded stripe Rhizoctonia Solani Kühn on commercial fields at the Portuguesa state, Venezuela. Agronomía Trop. [online]. 2008, vol.58, n.4, pp.383-390. ISSN 0002-192X.

The objective of this study was to determine the effect of a biofungicide, Trichoderma harzianum, on the incidence and severity of the disease maize banded leaf caused by Rhizoctonia solani Kühn fungus, anamorph of Thanathephorus cucumeris, in commercial fields of corn, at the Portuguesa State, Venezuela, during the rainy season of the 2001 year. We selected commercial plots in eight locations normally affected by the disease. In each place the plots were divided in two areas, each one of about 5 ha; in each place one of the 5 ha was treated with the biofungicide, and the other one was allowed without any application. The biofungicide dose was split: at the sowing time in the seed (100 g of biofungicide /20 kg of seed), and 30 days after sowing in a dose of 3 liters of the commercial product /ha. Treated and no treated plots were sowed at the same time. We evaluated the incidence and severity of the fungus at about 70 days of the crop cycle, in 5 areas inside each plot. The incidence was analyzed using a factorial arrangement in a randomized block design with 5 replications, while the severity was analyzed using the Friedman non-parametric test. We found that the biofungicide reduced the disease in 50% in all locations. This result showed the beneficial effects of the biofungicide, and it represent a valuable, successful and environmental friendly alternative to control the disease.

Keywords : Zea mays; Thanathephorus cucumeris; incidence; severity.