University of Illinois Extension
Bruce Spangeberg

These articles are written to apply to the northeastern corner of Illinois. Problems and timing may not apply outside of this area.

Stateline Yard & Garden

Preventing Annual Tomato and Apple Problems

June 14, 2001

When growing vegetable or fruit crops, there are some problems to be expected about every year. Apples and tomatoes are two popular crops that each has common problems that can be prevented.

On tomatoes, blossom end rot is an annual problem that can vary with the weather each season. This is the problem discovered when you pick a ripening tomato and find the underside black and rotten. Blossom end rot is due to a lack of calcium as the fruit develops, which in turn is usually due to fluctuating soil moisture as the fruit develops.

Mulching the soil and watering as needed during dry spells that may occur should keep the problem in check. Even though we have had plenty of rain lately, monitor the soil conditions closely as we advance into summer and fruit is developing on the tomato plants.

On apples, one common discouraging problem is to find bumpy apples with streaks of brown inside. This is the work of the apple maggot. Adults are small flies that typically start laying eggs in early July and continue through August.

Adult apple maggots will lay eggs on the skin of the apple, damaging the fruit even if the eggs don't hatch. Larva tunnel into the apple, and a soft rot will follow, causing the brown trails in the flesh.

There is plenty of time to prevent damage, as apple maggot typically is out in July and August. One control option is to continue applying insecticides, which are included in multipurpose fruit sprays, at two-week intervals throughout July and August. Another option, which does not require insecticides, is to use "sticky traps" to catch the adult fly. Red spheres coated with adhesive and hung in trees can be used to "trap-out" apple maggots from backyard orchards. This is only for apple maggot control however, not other insect pests or diseases.


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