By Lenny Wells
University of Georgia
Most of the varieties today are simply chance seedlings that someone discovered and propagated through the years. Some will be more susceptible to insects and disease. Some develop nuts sooner in the life of the tree, while others will bear nuts more consistently than others.
For trees that require low inputs, some varieties are better than others. Choose your yard or home-garden trees from them. Since spraying trees in your yard isn't an option, the main trait to look for is resistance to disease.
ScabPecan scab is the primary disease affecting pecans. It causes the nuts to develop black spots, which can merge together as the season progresses until the nuts are completely covered and fall from the tree. The disease thrives in rainy weather, making some years worse for pecan scab than others.
Several varieties have enough scab resistance to be grown in most home situations. These include Elliot, Kanza, Gloria Grande and Sumner. Because pecan trees are cross-pollinated, you must have at least two varieties to have nuts.
Other varieties that show good disease and insect resistance include Jenkins, Syrup Mill, Carter, Gafford and McMillan. These five are from the Auburn University pecan breeding program and were selected for low-input situations.
Only a few nurseries propagate these varieties. Your University of Georgia Cooperative Extension county agent can point these out. Graft wood for budding or grafting your own trees may also be available.
Second keyWater is the second key. In most years, you simply can't grow pecans without some type of irrigation.
The most critical time for watering pecans is the first two weeks of September. During this time, pecan trees need about 1.5 inches of water per week. If you don't water at any other time, water then.
The more water the trees get in June and July, the larger the nuts will be and the more water will be required in August and September to fill the nuts.
If you don't plan to water your pecan trees, avoid cultivars that bear very large nuts. Small nut size is an advantage in dry years, because the tree requires less water and energy to completely fill its kernels.
Third keyThe third key is fertilization. If the trees are to produce a good crop, the ends of the new branches should grow 6 inches each year.
If you don't get a leaf analysis or soil test, broadcast 4 pounds of a complete fertilizer such as 10-10-10 for each inch of trunk diameter at 4.5 feet above the ground. Apply it from mid- to late February to mid- to late March.
Zinc nutrition is critical in pecan production. To find out how much zinc your tree needs, it's best to get an analysis of leaf samples in late July or early August. Get mailing kits and instructions for taking samples from the county UGA Extension office (1-800-ASK-UGA1).
If you don't get a leaf analysis, apply 1 pound of zinc sulfate to young trees and 3 to 5 pounds for large trees each year.
The soil pH needs to be 6.0 to 6.5 to make the essential nutrients available to the tree. Apply lime as suggested in the soil test report to correct low pH.
In your yard or home orchard, you're limited as to the level of care you can provide. But planting the right trees and giving them what they need when they need it will go a long way toward having the tasty pecans you're hoping for.
(Lenny Wells is a pecan horticulturist with the University of Georgia College of Agricultural and Environmental Sciences.)