Dicarboximide sprays at harvest were the traditional method of chemical control of Botrytis . However, Botrytis has developed resistance to the dicarboximides such as Ronilan and Rovral. Therefore such chemicals must be used sparingly and other methods of Botrytis control are recommended. Growers do not apply fungicides for Botrytis and industry data suggests that stem-end rot losses are lower. Research is underway to investigate why organic fruit have less Botrytis problems.
Control starts on the orchard.
As mentioned above, an open canopy, plenty of air movement in the block and good orchard hygiene to remove sources of Botrytis spores such as blowouts, all go a long way to reducing the risk of Botrytis on your orchard. Minimising fruit handling will reduce spore transfer. The inside of canvas picking bags can become contaminated with Botrytis spores attached to kiwifruit hairs. Research has shown that fishing net type bags may reduce Botrytis build-up in the bag. Fruit need to be condition checked in coolstore.