The soybean powdery mildew, caused by Erysiphe diffusa, is considered a sporadic disease which can cause losses when it reaches epidemic proportions. This study aimed to evaluate the efficiency of potassium bicarbonate (Kaligreen®) in controlling soybean powdery mildew. Sprays of both potassium bicarbonate at concentrations of 0, 0.25%, 0.5%, 0.75% and 1.0% and fungicide (pyraclostrobin + epoxiconazole), as well as assessments, were weekly carried out. Leaves were collected for ultrastructural analysis by scanning electron microscopy. Potassium bicarbonate controlled the disease at all concentrations but caused phytotoxicity from 0.5%. In the ultrastructural analysis, the product had a direct action on the pathogen, causing wilting and reduction in conidium germination. The product has the potential to control the disease, but the concentration to be recommended should be adequate, as well as the frequency of application to prevent phytotoxicity problems.
bicarbonate; biocompatible products; soybean diseases; powdery mildew; Erysiphe diffusa
