Diseases and pests

Powdery and downy mildew are the two dominant fungal threats, both introduced to Europe from America in the nineteenth century. They are managed with sulfur and copper respectively — including in organic viticulture, which is why copper accumulation in soil is a genuine criticism of organic certification.

Botrytis is the fungus that is either a disaster or the basis of great sweet wine, depending entirely on the weather.

Trunk diseases such as esca are a growing and poorly solved problem, killing mature vines and reducing the stock of old plantings.

Pests include phylloxera (historically catastrophic), nematodes, and birds, which are a larger practical problem than they sound.

Humid regions face far more disease pressure than dry ones, which is why Atlantic and continental regions spray more than Mediterranean ones and why disease-resistant varieties matter more in England and Wales.