Important ONfruit posts for grape growers

Grapevine viruses, September 2017

W. McFadden-Smith (OMAFRA), S. Poojari  and J.P. Parent (AAFC)

Symptoms of Grapevine leafroll disease (GLD), caused by a number of GLRaVs, are more apparent on red-fruited vinifera cultivars than whites and they vary based on variety of factors including environmental conditions, cultivar, age of the vines, stage and severity of (one or more than one virus) infection and viral load. Continue reading →

Sooty mould — a sure sign of mealybugs (and sometimes scales)

W. McFadden-Smith (OMAFRA), S. Poojari and J.P. Parent (AAFC)

A few weeks ago, it was easy to find mealybugs and scales on foliage and fruit in vineyards that had not been sprayed with Movento.  Mealybugs and scales secrete a sugary substance that not only attracts ants, but also acts as a food source for superficial sooty mould fungi.  The latter are not an issue for wine grapes but can make table grapes unmarketable.  However, the presence of sooty mould is a good indicator of the presence of the vectors of Grapevine Leafroll-associated Viruses (GLR-aVs). Continue reading →