In the March 20 column were guidelines for training stone fruit trees. Today’s column has guidelines for training pome fruit trees.
Pome fruits are deciduous trees that are members of the Rosaceae family. The most common pome fruits are apple and pear. The flesh of these fruit develops from the fused petals and sepals of the blossom. The flesh surrounds the female organ that forms the core. In the core are multiple small seeds that are protected by a tough membrane. All of a pome fruit is edible, including the core.
Pome fruit trees are trained to the modified leader system, also called a multi-leader system. The modified leader system is a “modification” of the central leader training system, where one main leader dominates. In the modified leader system three to five lateral branches are trained. Ideally the laterals arise 90 degrees from each other around the circumference of the tree.
It is important to have the laterals spread evenly around the main trunk to allow for light and air penetration. With adequate light fruit production is enhanced and adequate air penetration reduces disease incidence.
Once the framework is established, little pruning is needed as even light pruning encourages vigorous interior growth. Vigorous growth is vegetative; this wood will have delayed fruiting.
Pome fruit have two types of buds: fruit buds, from which flowers and fruit form and vegetative, growth buds, from which leaves but not flowers, develop. Vegetative buds are slender, smaller and more pointed.
The fruit of apples and pears are borne on short, stubby stems called spurs. Enhancing spur production is the most critical consideration in pruning apples and pears. Spurs develop on two-year-old wood.
Encourage fruiting spurs by removing competing suckers and unproductive wood. Locate spurs before pruning since removing the spurs removes the fruiting wood.
The technique used in training young trees to the modified leader system is to spread lateral branches by bending upright branches to a wide angle with dowels to be used as wood spreaders. The idea is to spread vigorous branches to as nearly horizontal as possible without breaking the wood. Wedge dowels into the laterally bent branch against one of the main leaders. After several years the wood spreaders will no longer be needed as the branch will have maintained a wide angle and the dowels will no longer be needed.
Ellen Peffley Harp, a retired professor of horticulture at Texas Tech University, writes about gardening for several Texas newspapers.
