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.

Harvest your apples before the temperature drops below 30 degrees F.

Cold temperature injury of apples results in the formation of ice crystals in the spaces between the cells.  When this occurs the cells may die.  A common symptom of freeze damage is seen in the photo below.  This photo is courtesy of Washington State University.

The temperature at which apples suffer freeze damage ranges from 27.3 to 29.4 F depending on variety for an average of 28.4 F. I would suggest apples be harvested and stored in a frost proof area if the temperature is forecast to go below 30 degrees F. 

If you are unable to pick the fruit when temperatures below 30 F. are forecast, as may occur with later ripening varieties, wait until the apples have thawed before harvesting and/or handling.  This will limit the extend of the damage.