Black spot, grape anthracnose

Elsinoe ampelina

E. ampelina affects two species of Rubus and three species of Vitis. Specifically, E. ampelina affects blackberries, raspberries, mountain grapes, fox or concord grapes, and the European wine grape. Anthracnose diseases can cause disease on a variety of plants, but the primary host for E. ampelina, is grape.
Anthracnose on grape presents itself as lesions on shoots, leaves, and berries. Lesions will first appear on young shoots, showing up as small circular reddish spots that will later become larger and create grey lesions which appear sunken. The lesions will eventually develop margins that are a dark reddish-brown to violet-black color. If left untreated, lesions on shoots will become larger and eventually kill the shoot. While these lesions may be very apparent and easy to identify, they can sometimes be confused for hail damage. Hail damage typically appears on only one side of the plants. Also, anthracnose lesions will have darker and more raised edge.
Anthracnose lesions on leaves and petioles look very similar to those on shoots. However, on leaves, the lesions will have dry grey or white centers that will eventually fall off, leaving a hole. This response by the plant is called a shot-hole. Should the lesions spread and the infection make it into the vascular system of the leaf, the anthracnose will prevent the proper development of the leaf and will lead to malformation or to the drying of the leaf.
Grape vines are susceptible to anthracnose before flowering all the way through fruit soften and coloration. Essentially, the berries are susceptible to the pathogen throughout the growing season. Anthracnose presents itself on the berries as small reddish circles, around a quarter inch in diameter, that will become sunken with a narrow dark brown to black border. Eventually, the center of the lesion will change color from violet to white or grey and become velvety. These lesions often look like a shooting target or bullseye. Should the disease spread to and affect the pulp of the berry, it will cause cracking, which opens the berry to secondary infections.

Plant Protection Products