Vine diseases the unknown and unspoken threat to UK viticulture

English wine growers are on a roll, the number of hectares of vineyards planted has risen from 923ha in 2006 to 1,500 hectares today. The boom has been aided by climate change, wealthy investors and a patriotic domestic market, but is the bubble about to burst?

Many growers will be anxiously scrutinising their vines for signs of Phylloxera, but there is a more serious potential problem for the UK which is trunk disease. Also known as Dead Arm, Black Measles and Black Goo, it's caused by a fungus which can impair vine performance and evenutally kill vines. It is particulary prevalent in the UK on young and recently planted vines.

Chris Foss of Plumpton College maintains the industry underestimates the seriousness of trunk disease and a researcher said a lot of producers are in denial about the situation, especially those whose vineyards have had disease for many years and hadn’t seen it. Out of 35 UK vineyards Foss visited all but one had the disease.

Trunk diseases are as graphic as the results. The two most threatening at this stage look to be Botryosphaeria (sometimes called ‘bot canker’), and Cylindrocarpon (sometimes called ‘black foot disease’). The former is easily transferred via pruning wounds. Worryingly, though, both diseases may already be present in recently planted nursery stocks.

Unfortunately there is no cure because it is hard to detect until the vine is pretty sick. However it can be stopped from spreading by removing the infected plants, treating pruning wounds and replanting.