Pest and Beneficials Search (search again)

Phomopsis cane and leaf spot

Phomopsis viticola

Infected leaves have small, yellowish spots with dark brown centers and may be puckered. On petioles, shoots and rachises, elongated black spots or streaks develop that make the tissue brittle.

Most shoot lesions occur on the basal three to six internodes. Young tissues are most susceptible. Symptoms appear 21 to 30 days after infection. Rachis and berry infections become apparent later in the season. Infected rachises wither, causing berries or entire clusters to drop prematurely. Berries turn brown and shrivel.

Prolonged rainy, cold weather in spring and early summer promotes the disease. The optimum temperature for infection is between 59 and 68ºF (15 to 20ºC). The fungus overwinters in bark of infected canes.


Phomopsis cane and leaf spot occurs in most grape-growing regions.

Pest and Beneficials Search (search again)

The MSU IPM Program maintains this site as an access point to pest management information at MSU. The IPM Program is administered within the Department of Entomology, fueled by research from the AgBioResearch, delivered to citizens through MSU Extension, and proud to be a part of Project GREEEN.