Stop Drop Control on Apples

Reprinted from the Rutgers Cooperative Extension Plant & Pest Advisory Fruit Edition
Vol. 4 No. 22, Aug. 31, 1999, p. 2

Win Cowgill, County Agricultural Agent

It appears that drought stressed blocks of Macintosh and other cultivars may be very prone to drop this
year.

From observations in PA, NJ and New England, Macintosh is dropping prematurely; especially in
drought stressed blocks.

There are only two materials labeled for stop drop on apples, ReTain and NAA.

At this point it is too late for ReTain applications on Mac's. ReTain must be applied thirty days before
anticipated harvest.

There may still time in northern New Jersey counties to apply retain on Red Delicious and later
ripening cultivars but the application window is closing rapidly.

NAA can be applied at 20 ppm and 10 ppm. The 10 ppm will hold fruit for one week the 20 ppm for
10-14 days.

If you have any other questions on ReTain or NAA, please do not hesitate to call me. Please refer to
pages 87-89 in the 1999 NJ Commercial Tree Fruit Production Guide for additional information.

1999 North Jersey Tree Fruit Annual Report

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