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.

Is your sweet cherry tree infected by a virus?

When sweet cherry leaves have a small leaf growing out of a vein, the tree has cherry rasp leaf. This unusual outgrowth is called an enation, literally meaning ‘small leaf’.

When your cherry tree exhibits these outgrowths, enjoy it while you can because it won’t be around very long. It will die! There is no cure once the tree is infected.

The virus is spread by dagger nematodes, Xiphinema americanum, by budding and grafting, and by root grafts. As with other nematode-vectored virus diseases, the symptoms appear on one or a couple trees in the orchard and spread outward in a circular pattern. This spread is due to the movement of infected nematodes and the natural grafting of roots between infected trees and non-infected trees. There is evidence of pollen from a virus-infected tree spreading the virus as well.

If you plant another sweet cherry tree in the same area within two years, you can expect your new tree to be infected due to the presence of virus-infected Xiphinema americanum in the soil. If you plant an apple tree during that time, it is likely to suffer from “flat apple” syndrome, if you plant a peach tree it may be infected but not show symptoms serving as a “Typhoid Mary” resulting in the infection of other trees. Field bindweed, dandelion, plantain and lambsquarter also serve as hosts for this virus and thus should be eradicated if anywhere near your backyard or commercial orchard.