The hills of Appalachia are dotted with old homesteads and forgotten orchards, fruit trees left to grow wild. Without management, these old orchards often carry inconsistent yields from year to year. While partially a factor of old age, trees fall into the habit of bearing fruit in cycles. This is referred to as alternate bearing. During a productive year, a tree carries a heavy load, branches breaking under the weight. The following year results in little to no production at all. A high yielding season depletes energy the tree would have put toward flowering the following year. All too often, alternate bearing is a habit the tree falls into. Without intervention, this is a cycle which will repeat itself to greater extremes until multiple years pass between fruiting.
In commercial markets, these habitual cycles can alternately drain and flood markets with inferior quality fruit. Fruit is too small during high yield years, yet too large and substandard during low yield years. This cycle leaves farmers with low net returns and inconsistent revenue.
The first steps to preventing alternate bearing begin years before the first harvest. Certain varieties are more susceptible to falling into the negative cycle than others. For example, Granny Smith, Gala, and Jonagold apples are less susceptible to alternate bearing than Golden Delicious or Fuji. Rome, Golden Delicious, McIntosh fall in the spectrum between.
Pruning and thinning are the two most important and widespread cultivation practices used to prevent alternate bearing of fruit trees. Pruning is the selective removal of plant parts for increasing yield, moderating plant size and shape, and managing light exposure in the tree’s canopy. In the context of preventing alternate bearing, pruning is a mass-thinning technique which removes large quantities of flower buds non-selectively. Thinning is the practice of selectively removing any extra fruit which would use energy better put towards the following year’s harvest. Thinning is typically completed within the two months after bloom. Hand thinning is accomplished by cutting individual fruits from a branch, leaving between 6 to 12 inches between fruits. The specific recommended distance varies by species and variety. By controlling yield through pruning and thinning fruit trees, a farmer can manage energy reserves of the plant and stabilize production.
Alternate bearing is the habit of a fruit tree to expend so much energy on fruit production one year that it barely produces the following year. Negatively impacting markets, alternate bearing is consistent only in producing inferior quality fruit. When planning an orchard or planting a backyard fruit tree, consider varieties which are less susceptible to alternate bearing and manage trees by pruning and thinning annually. These practices keep trees producing consistently from year to year, leaving the spooky old orchards for Halloween hauntings.