2018 Crop Protection Guide for Tree Fruits in Washington

Bioregulator Sprays

Thursday, April 26, 2018

To Extend Harvest—Sweet Cherries

The normal harvest period for sweet cherries can be extended by use of GA3 (ProGibb, Falgro, GibGro, N-Large).  The Falgro, Gibgro or N-Large products should be applied only as a single spray of 16-48 grams active ingredient per acre when fruit is light green to straw colored.  ProGibb formulations may be applied once or twice prior to harvest. If applying twice, make the first application when the fruit are translucent green and the second 3 to 7 days later when the fruit reach straw color. Apply approximately 1/3 to 1/2 of the total allowed amount of 16-48 grams active ingredient in the first application and the remainder in the second application. The application of GA3 delays fruit maturity from three to seven days and gives larger and much firmer fruit, bright green stems, and much longer storage life. Rates of GA3 can be reduced on lightly cropped trees. Complete coverage of the tree is important for uniform fruit maturity.

GA3 can reduce soluble solids and slightly reduce fruit bud set the following year. If reduction in return bloom is observed and not wanted, reduce the amount of GA3 applied per acre in subsequent years.

Tree Fruit Research & Extension Center, 1100 N Western Ave, Washington State University, Wenatchee WA 98801, 509-663-8181, Contact Us