Influence of Temperature and Leaf Wetness Period on Conidial Germination In Vitro and Infection ofCercospora kikuchiion Soybean

In vitro germination of conidia of Cercospora kikuchii was influenced by relative humidity. At 100% RH, 100% of the conidia germinated at all temperatures (15, 20, 25, 30, 35 C). No germination was observed below 92% RH. The temperature range tested did not alter the germination. The second fully developed trifoliate leaf of soybean (cv. Amsoy 71) was inoculated with a conidial suspension of C. kikuchii and then subjected to various temperatures (15, 20, 25, 30 C) and leaf wetness durations (18, 24, 30, 36 h). Disease severity was assessed 28 days later (...)