Jun 4, 2015

Three options on how to defruit young apple trees

Newly planted and young apple trees often set croploads that have negative effects to the vegetative growth of the tree in these early establishment years. Removing these fruits can be accomplished by three options as recommended by Michigan State University Extension.

If bloom is light, carefully pruning off the flowers with pruning scissors will eliminate the crop. Be careful to remove only flowers and not leaf tissue or growing points. Perform this task when conditions will remain dry for 24 hours to avoid causing fire blight infections sites. This is a good choice if other tree-training tasks require time in the orchard already.

Two spray applications of Sevin plus MaxCel at petal fall and again at 10 millimeters will thin young trees aggressively without stress to the tree. Use one quart Sevin plus two quarts MaxCel per 100 gallons.

Another spray choice is Sevin plus NAA at petal fall and again at 10 millimeters. This will also thin effectively, but NAA is a harsh thinner and some stunting of the tree will occur. Rates to use are 1 quart Sevin plus 15 ppm NAA. If conditions at these thinning times are excessively hot (more than 90 degrees Fahrenheit), some leaf drop may occur with the NAA combo. Red Delicious and Fuji are sensitive to NAA, therefore consider using the MaxCel combo on these varieties.

— By Phil Schwallier, and Amy Irish-Brown, Michigan State University Extension