Promoting apple drop
Barton County Extension Agent
The apple trees in your landscape have very likely given you some enjoyment during the past few weeks. The profuse apple bloom in 2010 has been exceptionally colorful. Typically, after a crop failure from late freezes the previous year, we get an unusual number of blooms. Often producing more fruit than the tree can support.
However, a question now is how to prevent the fruit from dropping in the lawn, on the sidewalk, driveway, patio, and into the drain gutters on your home. Where this situation is a problem, you can promote apple drop from your trees by applying the insecticide Sevin (Carbaryl).
Sevin is getting hard to find in some circles as the government has been trying to get rid of all the carbamates and organophosphates. Sevin is a carbamate and some uses of it have been taken off the market. So you may have to check around several places to find it in a liquid or wettable powder form.
The most appropriate time to apply Sevin and cause fruit drop while the apples are still small is soon after the blossoms have dried on the trees. Spray the trees thoroughly with 2 tablespoons of Sevin per 1 gallon of water. About 1 week to 10 days are required after applying the chemical before you will see results. The stems on the small fruit (about pencil eraser size or slightly smaller) will have the stems turn yellow and the fruit turn a dull color and begin to lose moisture and wrinkle. If these characteristics do not develop by 2 weeks after spraying, a second application may be necessary to promote fruit drop. The chemical is effective up to about 35 days after full bloom; however, apples become progressively more difficult to remove as they increase in size.