Other than a few specific situations like major hurricanes, severe drought or extreme amounts of rain, home pecans are fairly predictable and, if cared for properly, will likely yield a decent crop. The key point here is if cared for properly. Even with trends that show pecan crops do have off years, when pecan trees don’t bare regularly, there is usually a reason for it. Most homeowners tend to do absolutely nothing to their yard trees, yet expect a load of pecans each year. That simply isn’t going to happen.
The following are common problems and some suggestions for correcting them.
Disease and pests
Pecan varieties vary in production capacity, nut quality and susceptibility to disease and other problems. Some varieties are extremely susceptible to a fungus disease called pecan scab and will rarely produce a good crop when trees are unsprayed. Pecan scab seriously limits production on unsprayed pecan varieties — even varieties previously resistant to scab are being affected. Several other diseases can cause early leaf drop and decreased production. New varieties recommended for excellent to good disease resistance are Gafford, Excel, Lakota, Headquarters, McMillan and Baby B. Check online at www.alabamapecangrowers.com for more information and availability.
Aphids, pecan weevils, hickory shuckworms and several other insects can also limit pecan production. Sanitary measures like removing and destroying fallen leaves, shucks, nuts and twigs aid in controlling many insects and diseases. Spraying may not be feasible for growers with only a few trees, but if you would like spray recommendations for controlling pecan pests, they are available from your local Extension office.
Pecan trees grow best on sandy loam soils with well-drained subsoil. Growth and production is often poor on heavy clays, poorly drained soils and on deep sands unless an intensive irrigation and fertilization program is maintained.
Inadequate lime or fertilizer
Lack of lime, nitrogen fertilizer and zinc are common limiting factors in pecan production. Fertilize according to soil and leaf sample recommendations. Apply fertilizer in March on large trees. For young trees, fertilize in March with 13-13-13, lime and zinc. Apply half ammonium nitrate in April, half in June. Broadcast fertilizer on the surface in a circle twice the branch spread of the tree.
Too much/too little water
Waterlogged soils with standing water do not provide aeration for roots. However, lack of water, especially during dry periods of summer, frequently results in reduced yields and quality, and in weakened trees that may be less productive in following years. Choose well-drained soil, provide drainage for excess water and keep trees watered during dry periods.
A single isolated pecan tree usually won’t be effectively pollinated, since most varieties shed pollen either too early or too late to pollinate the female flowers of the same tree. If a number of seedling pecan trees or trees of several different varieties are already growing within a few hundred yards, a tree for pollination is probably unnecessary. Another reason for poor pollination is wet weather during April and May. Rain washes off pollen and may restrict movement of pollen by wind.
Pecan trees must have good exposure to sunlight to produce good crops. When limbs begin to overlap the limbs of neighboring trees, remove the least desirable trees to prevent overcrowding.
No new plantings
Most home pecan trees and established orchards are older than dirt. These pecan trees are of the old varieties that were planted over 50 years ago. Varieties like Stewart are wonderful pecans if and when they produce but are highly susceptible to disease. Odds are they will not reach their potential today without a spray program. Homeowners who want low-maintenance pecans, as well as a decent crop each year, must begin investing in better varieties of pecans. Our old mature trees will not last forever and are slowly disappearing. New healthy trees can begin producing as early as six years.
For help on other home and garden questions, contact your local county Extension office or visit us online at www.aces.edu.
Shane Harris is an Extension Agent for the Alabama Cooperative Extension System.