Name one major threat to vineyards due to climate factors.

Drought and excessive rainfall are significant threats to vineyards because both can drastically affect grape quality and yield. Drought can lead to water stress in vines, which might result in smaller berries, reduced acidity, and, ultimately, lower quality wines. In some cases, prolonged drought can even cause vine death if the roots cannot access sufficient water.

On the other hand, excessive rainfall can lead to a host of problems such as increased disease pressure, particularly with fungal diseases like powdery mildew and botrytis bunch rot. It can also enhance berry splitting, which reduces the quality of the grapes and complicates the harvest. Wine grape varieties often thrive under specific moisture conditions, and deviations from these can significantly impact production outcomes. Hence, both drought and excessive rainfall are major concerns for vineyard health and productivity in the face of climate challenges.