Controle de Erysiphe diffusa com óleos essenciais e leite: estudos ultraestrutural e do modo de ação

Abstract

Among the economically important diseases of soybean, powdery mildew, has become a constant threat since the outbreak in 1996/97. Essential oils (OEs) and cow whole milk (LE) consist of alternative products for disease control in organic farming. Thus, the present study was conducted in two stages: In the initial stage was aimed at selecting and evaluating the potential of essential oils and hole cow milk to control powdery mildew of soybean products by selecting promising and, in the next stage, aimed at evaluating and elucidate the mode of action of these promising products in combination in order to explore possible additive effects. For this were carried three experiments for the initial selection of alternative products promising compounds for essential oils (OEs) and whole milk (LE) and four experiments to determine the effectiveness and elucidate the mode of action of the combination of effective products selected in the first stage. Were selected products composed of OEs of lemon grass (CL) and citronella (Ci) and whole milk (LE) in the first stage, already highlighted in the next step is the product of the combination of OE CL and LE that even with 50% reduction in the concentration of active ingredients (CL LE) / 2 has shown effectiveness against powdery mildew in soybeans. This product of the combination of activeingredients showed an additive effect in controlling disease severity and has both curative action mode featuring direct effect on the pathogen such as preventative as inducer of resistance of plants, both led a reducing the severity of the disease.