Botryosphaeria dothidea causes chestnut black rot. However, treating chestnuts with water heated to 50 °C for 30 or 40 min and 52 °C for 30 min resulted in a < 30% rate of rotting. Moreover, compared to untreated controls, the heat treatments extended the number of days required for the appearance of symptoms by six. Treating naturally infected chestnuts (infection rate: 22%) with hot water decreased the rotting rate by 4% to 6% compared to untreated controls; this percentage is lower than the 12% achieved with methyl iodide fumigation. Heat-treated chestnuts either inoculated or naturally infected with B. dothidea and then refrigerated at 5 ℃did not show symptoms for five months, while untreated controls showed symptoms after about two months.

View full abstract