Claudia Adriana Görgen
Abstract:
Aimed to evaluate the integrated effect of crop control methods, by sowing Brachiaria ruziziensis for no-tillage straw formation, and biological control with Trichoderma harzianum '1306', commercial product Trichodermil®, in reducing density of inoculum and incidence of white mold. Carried out in Jataí - GO municipality, in a commercial soybean area naturally infested with Sclerotinia sclerotiorum in the 2006/2007 and 2007/2008 harvests. Implanted in March 2006 in 630 m² plots, in the presence and absence of B. ruziziensis and applications of T. harzianum '1306' at dosages 0, 0.5, 1.0 and 1.5 L.ha-1 in one or two seasons (March and October). The soil was sampled for sclerotia quantification, in March for initial inoculum evaluation, in June, and in September for sclerotia viability evaluation in BDA medium. The number of sclerotia, the viability and parasitism of sclerotia by Trichoderma spp and other microorganisms, the number of apothecias, the incidence of the disease and the production components were evaluated. Brachiaria straw reduced sclerotia viability and number of apotheciums, and at 0.5 and 1.0 L.ha-1 doses of T. harzianum 1306 sclerotia parasitism was higher. The incidence of white mold was lower in the residual effect of the presence of B. ruziziensis straw at doses 0.5 and 1.0 L.ha-1 of T. harzianum '1306'. Soybean yield was higher at 0.5 L ha -1 of T. harzianum '1306'.
