Effects of environmental conditions on growth of Stagonosporopsis cucurbitacearum causing internal fruit rot in cucurbits

The Cucurbitaceae are a large and diverse family containing several important commodity crops in many parts of the world. In recent years, fruit rot caused by Stagonosporopsis spp. became a major disease in both field-grown and greenhouse-grown cucurbits. Yield losses due to Stagonosporopsis can show seasonal peaks up to 30%. Despite its economic importance, information on growth characteristics of S. cucurbitacearum is limited. A more profound understanding of the influence of individual environmental factors on growth of the fungus is a first step toward the development of sustainable management strategies to prevent outbreaks of this disease. Optimal growth of the pathogen occurred in temperatures ranging from 20 to 25°C, and in a neutral and acid (pH 4) environment. Although S. cucurbitacearum is described as an aerobic fungus, it still showed considerable mycelium growth at low oxygen concentrations.