Apple problems are peskyPublished 6:04am Monday, October 14, 2013
The most common pest of apples in this area is apple maggot. You may have eaten the maggot all unknowing.
The apple maggots emerge in mid July. The females insert eggs just below the skin. The eggs hatch into larvae that begin burrowing through the flesh. If you look very closely, you will be able to see a small oviposition scar on the apple with a trail where the maggot left. There are no holes left when the maggot feeds and the maggot itself is very difficult to see in the flesh of the apple. Leave a soft fleshed apple at room temperature for a few days, then you may be able to see the brown streaks in through the flesh. If there are a lot of maggots in the apple, the fruit will be stunted with a knobby surface. Don’t eat that one. The apples with a few maggots are considered to be eatable or, you can cook them.
McIntosh and Haralson have either high acidity or very firm flesh. The maggots may lay eggs in these two but they won’t hatch. Not so in Chestnut, State Fair and Honeycrisp. They could be crawling with the little critters. Eat with caution unless you don’t mind a little meat with your fruit.
Apple scab is a devastating disease worldwide. It is usually a leaf disease but the fruit can be affected during the primary infection period, May through mid-June. Fruit will be deformed often with huge cracks. It can actually defoliate some susceptible varieties. Ornamental crabapples are the most susceptible to this disease. About the only thing the homeowner can do is pick up all diseased leaves if the tree isn’t too infected. If it is totally naked, the best bet is to prune it at soil level and get a different crab.
If you have red cedar trees and apple trees in the same area, you need to be aware of cedar-apple rust. The fungus moves from cedar to apple and back. You can see the fungus in the spring. It looks like a glob of orange jelly hanging from the cedar.
Cut it off and bag it. If you do get the rust, you may notice rusty patches on the leaves. On the apple it makes a round rust colored lesion. It can go into the fruit. Wealthy is most susceptible and can be defoliated by the disease.
Fireblight is another devastating apple and mountain ash disease (bet you didn’t know that both these tree cousins are in the rose family). Fireblight is caused by a bacteria that infects either the blooms or the new growth.
It moves during periods of heavy rain when splashing moves the bacteria to new growth. Once established, it moves very fast down the infected branch causing the branch to die within a week after infection. When the branch dies the tip bends over giving the branch the easily diagnosed “shepherds crook.”
There is a distinct line between infected and healthy tissue. Cut the infected branch off as soon as possible, disinfecting your tool with Listerine mouthwash between cuts. The most susceptible apples are Fireside and Honeygold.
Seems like the best-tasting apples the homeowner grows are the ones most apt to get sick. Still, nothing is better than picking an apple off your own tree and enjoying it right there. Just don’t look too closely for the little maggot enjoying the same treat.
Bev Johnson, master gardener in Otter Tail County.