Why do my pecans not produce every year?

Alternate bearing in pecan production means that a tree bears a relatively heavy crop of nuts one year and a lighter one the next. It is characteristic of pecan trees and other hardwood forest trees. To reduce the effects of alternate bearing, choose cultivars that tend to be consistent annual bearers and then practice good orchard management. Healthy trees of any cultivar are better able to bear pecans consistently from year to year.

For a tree to grow vigorously enough in the spring to produce the leaves and flowers it needs for a good harvest, it must carry enough assimilated food reserves over the winter to support its first flush of growth. For that reason, anything that interferes with a tree's ability to produce and store nutrient elements, carbohydrates, etc., also interferes with its ability to produce nuts. Among these are the nut crop itself, the age of the tree, and the tree's health.