Pecan trees experience long a juvenile period during which little or no fruit is produced. Within this period, all growth is focused on vegetative growth. This is quite possibly an adaptation that allows young trees to quickly compete among more mature trees for canopy space in nature. Most pecan trees begin nut production when trees are between 4 and 12 years of age. Over the course of its life, tree age, spacing and cultivar will largely determine pecan production. These three factors are the strongest indicators of pecan quality and quantity.
Age and Productivity
Generally as a pecan tree ages, its fruit yield will gradually increase. Many trees that begin production after four years will have significant yields after eight or nine years. After about 20 years, the yield of most pecan trees will start to level off. Despite this leveling off, a single mature pecan tree can provide 400 to 1,000 lbs of nuts per year for 100 years or more.
Commercial pecan growers place a high value on trees that able to bear fruit young in life after a relatively short juvenile period. Trees cultivars that have this ability are called precocious. Unfortunately, many precocious cultivars tend to alternatively bear and have a lower nut fill capacity, particularly as they mature. For best results, do not over value precociousness when selecting a cultivar. Instead choose one that is well-adapted to grow where you live. Keep in mind, pecan trees are a long-term home garden investment.
Spacing and Productivity
When fully grown, pecans are large trees with significant space requirements. Consequently, proper tree spacing is one of the most significant hurdles to long-term pecan production. Mature trees requires at least 60 feet in circumference. When planting seedlings, growers must decide to either space trees in 60-foot intervals and grow inter-crops between trees or over plant with the intention of removing about half the trees in about 15 years.
Alternate Bearing Tendency
Alternate bearing is characterized by heavy fruit production one year followed by a year with low fruit production. Like many other fruit trees, pecan trees exhibit this tendency. Diagnosing the underlying cause of this problem can be difficult. However, crop load management, by way of tree thinning, may encourage more consistent yields. Tree thinning involves selectively removing part of the crop in order to provide larger, better quality pecans overall. Research indicates that while the current year’s crop may be reduced it will improve crop production in subsequent years.