Black Rot in Grapes

Black Rot in Grapes - Photo: Tim Weigle, Cornell University

Black Rot in Grapes

Black rot is a fungal disease that can infect the leaves, shoots, berries and cluster stems of grapes. Grape growers often find black rot to be an insidious disease. The grape clusters will appear to be developing normally until suddenly the fruit will start to turn brown, then black, with numerous round, black spheres on the surface. The grape berry will eventually shrivel up into a hard, raisin-like mass called a mummy. The pycnidia on the mummy’s surface contain inoculum, or spores, that will over winter and be available to infect the grape crop the following year. To read more abut this disease, its symptoms, impact, disease cycle and management please see the websites below.

https://grapesandwine.cals.cornell.edu/newsletters/appellation-cornell/2014-newsletters/issue-17/managing-black-rot

http://nysipm.cornell.edu/factsheets/grapes/diseases/grape_br.pdf

Last updated December 8, 2014