Botrytis cinerea is a weather driven fungus which causes the grapevine diseases botrytis bunch rot and grey mould. High humidity or prolonged rain in conjunction with cool or mild temperatures results in persistent moisture on berry surfaces and promotes infection and disease development. Previously infected sites and sheltered vineyard areas such as hollows are at greatest risk of developing the disease.
Managing botrytis can be a challenge because many factors contribute to infection and disease development.
Botrytis can cause two problems during winemaking as it produces the oxidative enzyme ‘laccase‘, which in the presence of oxygen can cause oxidative spoilage and secondly the presence of Botrytis can lead to the presence of a mouldy character in the resultant wine. Preventing this enzyme from causing damage requires techniques that minimise or eliminate exposure to oxygen.
Eliminating or minimising the quantity of botrytis affected fruit processed will reduce the potential effects of oxidative damage, however a holistic approach is required that involves many aspects of the winemaking process.
Botrytis infection in red grapes will require different treatments to infection in white grapes, and the following processing strategies can help reduce the oxidative damage that can be caused by botrytis infected fruit.
» read more Strategies for processing white and red fruit.