Blueberry Leaf Mottle

Blueberry leaf mottle, affectionately known as BLMV, is a Nepovirus. Nepoviruses are transmitted by nematodes most of the time. Not this one. [I couldn't find a usable photo of blueberry leaf mottle, but this image is close.]

Cherry leaves infected with leaf mottle (H.J. Larsen, Bugwood.org) CC BY-SA 3.0

Unfortunately, this disease is spread by honey bees as they collect pollen. It can also be seed-borne, though this is rare. As far as I could learn, blueberry leaf mottle is currently only found in Michigan, Canada, and South Korea. Of course, things can change in a single day. Case in point, this virus has decided that blueberries are no longer their only host. Grapes ​are now on the menu.

Blueberry leaf mottle symptoms

True to its name, leaf mottling is the primary symptom of blueberry leaf mottle. Infected leaves are often lighter in color and smaller than healthy leaves and might be puckered or otherwise deformed. Stunting and dieback may also occur. Infected grapevines exhibit delayed budbreak, elongated fruits, and sparse fruit clusters.

How to manage blueberry leaf mottle

The kicker about this disease is that symptoms don’t appear until three or four years after the plant is infected. And there are no known treatments. So prevention is your only option. To prevent blueberry leaf mottle in your garden, buy certified disease-free rootstock. Infected plants must be removed and thrown in the garbage.

I hope your blueberry bushes stay healthy and productive.