Thinning Fruit on Trees

Want more fruit? You may need to thin. Here's why!

Searcy, Ark. – 

Fruit trees grown under favorable conditions set more fruit than can be properly developed.  The practice of fruit thinning contributes to your orchard’s success. It is recommended for apples, pears, nectarines, plums, and peaches. As a county agent I find it difficult to convince people to thin the fruit on their trees.

However, there are several reasons why fruit crops should be thinned. First of all, a portion of the fruit is removed so that the remainder will develop to an adequate size. Thinning of fruit balances the amount of fruit left on trees with the leaf surface that provides the energy to grow and ripen fruit.

Secondly, leaving too much fruit on a tree creates a burden for the tree and takes energy from other processes occurring at the time of fruit development. One of those processes is fruit bud development for the coming crop. When too much fruit is left on a tree, fruit bud production will be limited, causing the tree to have a light crop the following year. Thinning increases the plant’s ability to form flower buds for the next year, provided the thinning is done early enough. Failure to thin can lead to biennial bearing problems i.e., over-production one year followed by a year of extremely low yields.

A third reason to thin fruit is to reduce limb breakage that occurs from too much weight, as the fruit grows. Finally, insects and disease are more difficult to control when fruit hangs in clusters.

Hand thinning is the easiest and safest method for removing excess fruit. Begin hand thinning when the fruits are about ½ inch in diameter. Start at one end of a branch and systematically remove fruit, leaving one fruit every 6 to 8 inches. Keep in mind that only 5% to 10% of the tree’s flowers are needed to set a full crop of fruit. When choosing which fruit to leave look for the largest fruit. Fruit that is small or damaged should be dropped first. If you have twins or triplets only keep a single fruit. Homeowners should thin fruit as early as possible, or within the first 20-30 days after petal fall. Removing these small fruits early will keep energy available for the fruit that remain and fruit buds for next year.

Orchard floor sanitation is very important in maintaining healthy fruit trees. Fungal pathogens over-winter on dried leaves, pruned limbs, and decaying fruit left on the orchard floor. These fungal spores can infect healthy trees and fruit in the spring when temperatures are warmer and rain, irrigation water and wind spread the spores. Diseased branches that have been pruned need to be disposed of as soon as possible. Thinned fruit needs to be removed from the orchard floor. 

As the fruit matures and branches begin to bend from the weight you may need to take more fruit off each limb to protect your tree from limb breakage, especially when the tree is young. If you do not want to thin more fruit from the tree limbs you may need to use poles or props to hold up the limbs.

Remember when raising dwarf fruit trees to thin a little extra fruit off after bloom because the tree is not as strong structurally as a semi dwarf or standard tree. Dwarf fruit trees are precocious and tend to bloom and set heavier fruit crops at an early age. Protect their young branches from being overloaded in the first few years.

I always recommend pruning annually.  Pruning helps to maintain a healthy tree by removing wood that contributes to over fruiting. Pruning is the first stage of fruit thinning. Without proper pruning, fruit thinning is not a feasible practice.

The University of Arkansas System, Division of Agriculture is an equal opportunity/equal access/affirmative action institution. For more information you can contact your local county extension service, you can also follow Sherri Sanders on Facebook @UAEX.WhiteCountyAgriculture .

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By Sherri Sanders
County Extension Agent - Agriculture
The Cooperative Extension Service
U of A System Division of Agriculture

Media Contact: Sherri Sanders
County Extension Agent - Agriculture
U of A Division of Agriculture
Cooperative Extension Service
2400 Old Searcy Landing Road Searcy AR 72143
(501) 268-5394
ssanders@uada.edu

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