Late Drop in Tree Fruit Revisited

Gordon Johnson, Extension Vegetable & Fruit Specialist;

Fruit trees commonly set more fruit than they will carry and chemical, mechanical, or hand thinning is done to reduce fruit loads, increase fruit size, and limit alternate year bearing. Natural fruit drop also occurs and is often called “May Drop” or “June Drop”. This is often accompanied by some leaf drop, especially in stone fruits. In 2022, most stone fruits have a light crop so fruit drop will be due to other weather-related factors.

Natural fruit drop in 2022 will likely be a result of unfertilized or poorly fertilized seeds and cold injury during flowering in late March and April. Poor pollination can result from cold, rainy weather during bloom in self-fertile fruits such as peaches or poor insect pollinator activity during flowering in insect pollinated fruits such as apples. In stone fruit, some fruit that is not fertilized will remain on the plant for 25-50 days after bloom and then will drop before pit hardening starts. Other fruits may remain on the plant but will not develop properly. They may be misshapen or appear cube like.

Defoliation due to diseases such as peach leaf curl, chemical injury such as copper fungicide damage, or severe storms can also cause fruit drop.