Hexaconazole Application Saves the Loss of Grey Mold Disease but Hinders Tomato Fruit Ripening in Healthy Plants.

Hexaconazole (HEZ) is a triazole fungicide registered to prevent and control grey mold disease on tomatoes. Many triazole fungicides exhibit plant regulator functions. Therefore, it is necessary to understand the effects of HEZ fungicides on the growth and development of tomatoes. In the present study, the effect of HEZ on healthy and Botrytis cinerea ( B. cinerea )-infected tomato plants was investigated. We found that HEZ delayed fruit ripening when applied to healthy tomato plants and further changed the taste and flavor of these fruit. HEZ increased the size and prevented the rotting of the tomato fruit, thus saving grey mold infection-related losses. Moreover, compared with applying HEZ on healthy plants, the application of HEZ on B. cinerea- infected plants increased the metabolism of sugars, acids, and aromatic compounds in these fruit. Therefore, HEZ can effectively control fungal pathogens but reduce the quality of tomato fruit.