Often you read or hear that Anthracnose is a southern disease that thrives in hot humid environments. However, Anthracnose can be active at 36°F. At low temperatures Anthracnose needs 12 hours or more of wet tissue to cause infection. Over the last three weeks, many areas of Missouri have experienced these long wetting periods that have been exacerbated by below normal air temperatures.
The symptomology caused by Anthracnose on grape shoots can sometimes be confused with Phomopsis viticola lesions. Anthracnose lesions are round in shape and sunken whereas Phomopsis lesions are elongated and have raised edges (Figure 1).
Anthracnose can be controlled with Abound, Endura, Flint, Inspire Super, Mettle, Pristine, Quadris Top, Revus Top, Sovran, TebuStar, Topsin M, and Vintage. Good control is also provided by Captan and mancozeb products.
A good indicator species to determine if Anthracose is active is the Sycamore tree Platanus. Although the Sycamore is susceptible to a different strain of Anthracnose, Apiognomonia veneta, the environmental conditions needed for infection are similar to grape Anthracnose Elsinoe ampelina. Sycamore trees in Missouri are almost completely void of leaves right now as the result of Anthracnose caused by Apiognomonia veneta (Figure 2).