Premature apple drop

Fruit trees sometimes shed or drop fruit well before the fruit is mature. This is most common in apple trees but other fruits are affected too. There are many reasons a tree drops fruit prematurely.

Sometimes a fruit tree naturally sheds fruit – especially in heavy bearing years – because it does not have the nutrient resources to support a large amount of fruit. This typically happens in early summer and is sometimes called “June drop”.

Apples also give off a gas called ethylene which causes fruit to ripen. This ripening effect extends to the natural detachment of the stems of apples. When there is a heavy fruit load, more apples mean more ethylene and so apples drop early.

In heavy bearing years, thin fruit to reduce competition and encourage the tree to put more energy into producing fewer numbers of larger, higher quality fruit. See: Alternate or Biennial bearing fruit tree disorder

Environmental stresses such as wind, drought, hot/cold temperatures and summer pruning may contribute to early fruit drop. Other stresses such as nutrient deficiencies, salt toxicity and herbicide drift damage can also be causes.

Early fruit drop could also be a symptom of insect infestations. Examine the fallen fruit and the tree for signs of insect problems such as apple maggot or sawflies. If you don't want the fruit, go ahead and put it in the compost.

Sources:

Apple crop load management - Alternate Bearing. (2021, March 20). Retrieved March 23, 2021, from https://extension.psu.edu/apple-crop-load-management-alternate-bearing

University of MANITOBA - Faculty of Agricultural & FOOD sciences - Premature Fruit Drop. (n.d.). Retrieved March 24, 2021, from https://umanitoba.ca/faculties/afs/hort_inquiries/2232.html