By Island County Extension Agent, Donald B. Meehan
APPLE STORAGE
This is the time of the year when we think about finishing our apple tree harvest by getting our crop put away for the winter. This is a critical part of the harvest procedure since this part can determine what quality of apples you will have at time of consumption. I would like to share with you some thoughts about the storage of apples taken from WSU-Extension Plant Pathologist, Dr. Ralph Byther.
Dr. Byther suggests that you consider several things. An ideal storage temperature would be slightly below freezing (30-31 degrees F). Unfortunately, most of us will not have that capability, so we compromise by finding the coldest place possible - an unheated garage, shed, basement, or even better, buying an old, used refrigerator. If you grow MacIntosh, Macoun or Spartan, it is best to store them at warmer temperatures (35-36 degrees F), since they can be injured if they get colder.
The apples should be enclosed in a plastic container or bag to prevent desiccation and shriveling. The use of plastic containers, unfortunately, also promotes the unwanted buildup of carbon dioxide gas and fungus storage rots and spots such as those caused by Apple Scab. This becomes a more critical problem as storage temperatures increase. Punching holes in the plastic bag will allow carbon dioxide to escape and still retard shriveling.
To prevent storage rots, apples can be sprayed prior to harvest with the fungicide Benomyl at the rate of one heaping teaspoon per gallon (this is half the rate of Benomyl for the control of Apple Scab used during the growing season.) Because of the unusually high incidence of Scab disease this year in western Washington, storage problems with this disease are also expected to be intensified. Apples should be picked when they are dry, then kept in the coldest place possible. It is best to keep them in several small containers which can be periodically checked for rot. I am sure you know the story about one rotten apple spoiling the whole barrel. If the "barrel" contains only one or two dozen pieces of fruit, potential losses can be kept to a minimum.
If your storage area is an unheated garage or outside shed, prolonged sub-freezing temperatures during the dead of winter can ruin the whole batch. You may have to bring them inside during that kind of weather. Most years in a "normal western Washington winter" this is not necessary, but last winter many of us lost our winter apple supply during the late December and January cold snap.
In summary, Apple Scab in addition to causing problems during the growing season on leaves and fruit, can also affect apples in storage. Dry fruit, cold temperatures, and Benomyl fungicide treatment prior to storage are helpful in preventing this type of infection. As long as we are on the subject of Apple Scab, remember this fungus overwinters on the diseased leaves and fruits which are left on the ground. A good cleanup this fall will pay dividends next year in reducing the disease potential. Do not compost the leaves, but pack them out with the trash or burn them.
Return to Articles Index
Return to Garden Page
Providing Educational Support to the Island County Community