By Darrell Blackwelder
Cooperative Extension Service
Many backyard orchardists are excited to have an overwhelming amount of immature fruit hanging from their fruit trees.
But if not properly managed, fruit crops of apple, peach and pear may be a disappointment.
Tree fruit crops have dodged the late frosts with a heavy set of fruits. Ironically, trees laden with fruit can be a serious problem if not properly thinned.
Apple, peach and pear trees can easily be thinned now. Over-production of blooms is natures’ insurance against late frosts. A fruit tree can loose 90 percent of the bloom and still have an appreciable crop.
Thinning heavily fruited trees prevents unnecessary limb breakage due to excessive weight. Removing the excessive fruit also enhances the taste, color, size and quality of the remaining fruit left on the tree. Thinning allows additional sunlight to penetrate the tree canopy, necessary for carbohydrate production for the next seasons fruit set.
Heavily laden fruit trees consume excessive amounts of stored carbohydrates, reducing the bloom for the following crop. The tree reverts to a condition called biennial bearing or alternate bearing. The condition is characterized by the tree producing a heavy crop one season and a small or no crop the following year. Alternate bearing is common problem with apples and pears.
Most fruit trees require 35-50 healthy leaves per fruit for normal development. It is important to note that these leaves must be healthy for the duration of the growing period.
Apples, peaches and pears should be thinned 4 to 6 inches apart. A good rule of thumb is to leave space for one fruit to fit between each side of your hand. Be careful when removing small fruit from spur-type apple and pear trees. Spur-type trees produce buds that bear fruit from the same spur each year. Fruiting spurs are easily damaged or removed during the thinning process.
Obviously, tree fruits that are diseased, damaged or misshapen are removed first.
Mature apple and pear trees may be difficult to thin because of the height. Commercial producers with hundreds of trees often use straps tied to poles or plastic toy baseball bats to beat the fruit off the tree.
Many fruit tree species have a natural thinning period during the growing season. Often, natural thinning occurs too late in the season and does not correct the problem with over supply of fruit. Now is the time to consider removing excessive fruit.
It is also very important to maintain a rigorous spray schedule for tree fruits. Healthy, disease-free leaves are essential for good quality fruit. More detailed information on spray schedules can be found online at http://www.ces.ncsu.edu/depts/ pp/notes/Fruit/fdin002/ fdin002.htm
Darrell Blackwelder is and Extension Agent in horticulture at the Rowan County Cooperative Extension Center; call 704-216-8970.
Web sites:
http://www.rowanmastergardener. com
http://rowan.ces.ncsu.edu
http://rowanhorticulture.blogspot .com/