Tuesday, December 7, 2010

Flat Apple Virus


Flat Apple caused by Cherry Rasp Leaf Virus
 This apple is flatter than it should be.  It also has strange bumps and a very deep depression at the blossom end.  This problem is caused by a nematode-vectored virus known as cherry rasp leaf virus. The vector is Ziphinema americana, the dagger nematode.

This virus was first identified on Cherry where it causes the leaves to develop strange protrusion on the under side of the leaves called enations.  This virus also infects peaches and raspberries. Many weed species serve as hosts for the virus and when fed upon by the nematode will serve as the source of the virus to infect other plants..

Most likely this apple tree was planted in an area where a cherry or peach orchard once existed and where the dagger nematode was present. 
Note the deep depression on the blossom end and strange bumps
















Killing the virus in the tree is not possible without also killing the tree.  This tree will eventually die so it might as well be removed.

Removing the tree and treating the soil is an option but costly and dangerous and is only logical for commercial orchardists using the skills of a licensed pesticide applicator familiar with soil fumigation or soil treatments for nematodes.

For those with only a few trees, the best recommendation is to remove the tree, avoid planting cherry or apple trees or raspberries in this site and purchase those fruits from local farm markets or the grocery store.

1 comment: