Gordon Johnson, Extension Vegetable & Fruit Specialist; gcjohn@udel.edu
On Wednesday, April 6, I evaluated a mixed orchard for damage from several freeze events below 25 over the last 3 weeks. Apricots and Pluots were in the post bloom stage and had greater than 90% loss. Plums were also in the post bloom stage and while significant freeze losses of 50% or more are evident, final fruit load is still uncertain. Peaches and nectarines have severe losses but because they flower at very high numbers, final fruit load is still uncertain; however, the early flowering peaches and nectarines that were inspected showed the most damage and are expected to have very light fruit loads or no fruit. All early flowers on cherries were killed. Asian pears in bloom had over 70% losses (see photo below). Apples are pre- bloom and damage is expected to be low.
Freeze damaged Asian pear flowers. Note the black centers of flowers that have been killed by freezing.
Flowers and young fruit that are dead will be discolored (yellow, brown, black) or shriveled and often will pull off easily from the tree. Viable flowers and fruit will have green ovaries inside and out. You may have to cut open the ovaries with a razor blade to see if they have been damaged.