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 degrees 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.