As mentioned earlier, scab is a major disease of pecan trees and planting scab resistant trees is highly recommended for anyone on a small scale that does not have the ability to spray. Some of the recommended pecan trees that are scab resistant are hard to find at nurseries and may need to be ordered a year in advance.
Some pecan scab resistant cultivars recommended for the home planting include:
- Amling
- Adams 5
Miss L - Prilop
- Kanza
- Headquaters
- Lakota
- McMillian
- Elliott
- Avalon
- Gafford
These pecan cultivars do not produce the largest pecans. It is difficult for homeowners to properly manage pest problems so that large pecans can fill out properly. Pecan nursery sources and much more information on pecan trees are listed on the Alabama Pecan Growers website, www.alabamapecangrowers.com.
Pollination
Cross-pollination should be considered when planting pecan trees. Pecan trees are monoecious, which means they produce both female and male flowers on the same tree. However, that does not necessarily mean they are self-fertile. All the male flowers do not shed pollen when all the female flowers are receptive. Pecan trees are divided into two categories: type I and type II. Type I trees are called protandrous, and those trees shed pollen first before the female flower is receptive. The type II trees are termed protagynous, and the female blooms are receptive to pollen before the male bloom sheds pollen. For this reason, a grower would need a mixture of type I and type II trees for proper pollination. Pecan trees shed a lot of pollen so it does not have to be equal numbers of type I and type II trees, but they do need to be planted in the same area as pollen is moved from one tree to another by wind.
Tree spacing
When planting new trees, the spacing should be around 80 to 100 feet apart. Commercial farmers will plant much closer, but they also have the ability to spray the trees to manage pests. A wider spacing will allow more sunlight and more air circulation. Some growers will plant at a very close spacing to achieve more production per acre at a young age. Eventually, the grower will remove trees to the desired spacing and keep the production of the orchard increasing. Removing trees from an overcrowded orchard can increase production. If a grower is not willing to remove overcrowded trees at a later time, planting on a wider spacing in the beginning may be the best idea.
A large weed-free/grass-free zone of about a 10 foot radius or more around the trunk is desirable. Mulching the trees in that weed-free zone will also help. It may be hard for a small grower to irrigate, but irrigation during any dry periods and especially during the months of August and September would be beneficial.
Source : aces.edu