Producing Larger Apples
Thin out apples to
increase apple size
By: Sandy Feather ©2008
Penn State Cooperative Extension
Q. Four years
ago I planted several apple trees that are now starting to bear fruit.
The apples they produced last year were numerous but small, and they
had a lot
of bad spots. In order to increase the size and quality
of the fruit, what should I do?
A. Apple trees
often set more fruit than they can mature to a good size and
quality. If you permit all that fruit to stay on the tree until
harvest time, you will wind up with a lot of small apples.
Commercial orchards produce large, high-quality fruits by careful
attention to thinning the crop and following a spray schedule to
control disease and insect pests.
Apples naturally lose some of their abundant crop on their own. Some
pea-sized fruit will drop after the flowers lose all of their petals
(petal fall). These fruits usually have not been pollinated properly
due to cool, rainy weather or poorly timed insecticide applications
that interfere with bee activity. Late spring frosts can also damage
the flowers to the point that the fruit aborts. There is a second
drop from late May to early June. Commonly known as June drop, it
occurs from competition among the fruits for water and nutrients.
Hot, dry weather in spring can exacerbate it.
Although the amount of fruit that falls on its own might be
alarming, you often need to do some additional thinning to get the
larger fruit you desire. It is ideal to remove all but the largest
fruit from each cluster and space the apples 8 to 10 inches apart on
commercial orchards often rely on chemical thinning -- growth
regulators or Sevin (carbaryl) insecticide --
hand thinning is a better choice for home orchardists. Chemical
thinning does not permit the best positioning of fruit on the
branch, and you can remove too many apples this way. Save the
largest, healthiest fruits and remove the rest as soon as possible
after June drop. In addition to increasing fruit size, thinning allows the tree to
produce flower buds for next year's crop. Some varieties will bear
crops in alternate years if you do not thin out enough excess fruit.
Thinning also protects the trees from breaking under a heavy load of
fruit. Properly thinned fruit is exposed to more sun and better air
circulation, which can help reduce disease problems and allow more
even ripening. It is also easier to get good coverage with pesticide
applications when fruits aren't hanging in clusters.
As for the
"bad spots" in the fruits, there are many disease and insect
problems that could be responsible. Follow a spray schedule through
the growing season. Home orchard sprays are available that combine a
fungicide and an insecticide so that you can control disease and
insect problems with a single application. If you prefer to use
botanical insecticides, companies like Gardens Alive! offer organic
versions of combination fruit tree sprays.
The following spray schedule is taken from Penn State's publication
"Fruit Production for the Home Gardener." It's available for free
Helping your fruit
Types of apples