Jul 18, 2017

Grapevine leafroll virus a threat to Michigan grapes

Grapevine leafroll virus is one of the most common viruses affecting grapes in the world, and Michigan is no different. Though lighter cases can have a negligible impact on yield per vine, severe and very severe cases can destroy 35 percent and 65 percent of yield respectively, according to new research from Michigan State University Department of Plant, Soil and Microbial Sciences professor Annemiek Schilder.

Thanks to funding from the Michigan Grape and Wine Industry Council and MSU Project GREEEN, Schilder and her team set out to analyze the impact of grapevine leafroll virus on the yield and juice quality of Chardonnay grapes in Michigan, assess the distribution of the disease in a vineyard also infected with tobacco ringspot virus and determine the presence of insect vectors and the potential of the disease to spread.

Growers can watch a short video about this study at “Impact and spread of grapevine leafroll virus.”

The video concludes that grapevine leafroll virus tends to avoid vines infected with tobacco ringspot virus, which can kill vines, and also tends to infect several vines at once, indicating the disease can spread to nearby vines.

To access “Impact and spread of grapevine leafroll virus” and other wine grape research videos on a variety of topics, go to the Michigan State University Extension Grapes Research page.

Photo above: Reddening of the leaves and green veins are clear indicators of grapevine leafroll virus. Photo: Annemiek Schilder, MSU.

–  Cameron Macko, MSU IPM Program

Source: Michigan State University Extension