Influence of temperature and humidity on development of tomato powdery mildew

Abstract

Influence of temperature and humidity on development of tomato powdery mildew caused by Erysiphe cichoracearum DC. was investigated.
Conidia germinated on tomato leaves at temperature between 10 and 30°C, the optimum temperature being 20°C. They did not germinate at 35°C. Furthermore, they germinated in relative humidity between 45 and 100%. Conidia were produced at temperature between 10 and 35°C, the optimum temperature being 15°C, but they were produced scantily above 28°C.
Powdery mildew developed after conidial inoculation at temperature between 15 and 26°C, the optimum temperature being 23°C. It did not develop below 10°C and above 28°C. On relative humidity, it developed between 45 and 100%. It developed more severely between 85 and 95% than at 99 or 100% of relative humidity.