The benefits of fruit thinning and some helpful guidelines - East Idaho News
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The benefits of fruit thinning and some helpful guidelines

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Despite the prolonged cool weather this spring, it appears the fruit trees have dodged hard freezes. My mother-in-law’s apricot tree is loaded with fruit, so I spent some time thinning them for her.

Whenever possible, fruit trees will produce more fruit than they need, and more than they can carry. There will often be a natural fruit drop by mid-to-late June. Most fruit trees require additional thinning.

Thinning fruit will not only reduce stress on the tree branches, it will also result in larger and higher quality fruit. Proper fruit thinning will also influence next year’s production. The buds for next year’s crop are produced in this growing season.

The idea is to have enough leaves to produce the food necessary for good fruit and bud development.

Different practices are used to thin fruit. The most practical for homeowners is pruning and hand thinning. Pruning will reduce the amount of fruit-producing wood, but with our uncertain spring weather, it is better to not prune too severely. Hand-thinning is very labor-intensive but will give accurate results.

There is a lot that goes into the commercial production of fruit thinning. For homeowners, use these guidelines to thin fruit on your trees.

Apples and pears

Targeted thinning of apples helps to avoid or overcome alternate bearing apple trees. This is where one year the tree has a heavy fruit load, and the next year, very little.

Most apple and pear blossoms come in clusters. Thin apples by the time they reach about 1.0” diameter and pears at about 0.75” diameter.

The first step is to keep only one fruit per cluster. After that, thin the remaining fruit so there is 6 – 8 inches between fruits.

Peaches and nectarines

Peaches and nectarine fruit on last year’s wood. These new branches are about the diameter of a pencil (I call them pencil branhces). Residential peaches and nectarines should be trained with 4 strong scaffold branches. A full-grown tree can carry about 160 – 200 peaches, so smaller trees should have less. This means there will be 40 – 50 peaches per scaffold. If you average 1.5 peaches per pencil branch, that means each scaffold should have at 30 – 40 pencil branches on all the secondary, tertiary, and quaternary branches. The thinning of the pencil branches can be done with the winter/spring pruning.

PeachThin
Ron Patterson | Univeristy of Idaho

After fruit has set allow them to grow to about the size of a quarter and then thin them to one or two peaches per pencil branch. There should be a minimum of six inches between fruits. Thinning too soon may cause split pits and thinning too late will result in smaller fruit regardless of how heavily they are thinned.

Plums and apricots

Plums and apricots are quite easy. When they are about the size of a dime thin fruit so there is at least 3 inches between them

Cherries

At times cherries may benefit from thinning if the fruit load is excessive, but generally they don’t need to be thinned.

When you thin the fruit on your tree it is best to not look down. You will see a lot of small fruit on the ground, but if you look up you will see adequate fruit load with proper spacing. This will give you a good yield with high quality fruit.

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