Pecan Scab Disease

— Written By

Pecan Scab Disease

Pecan Scab Disease

More than likely, the black spots you see on pecan leaves and shucks are due to pecan scab. Symptoms of the disease appear as small, dark lesions on the leaves, twigs, and shucks. As the disease progresses, the lesions can expand and grow together. If we have a wet spring, you can anticipate problems with scab on leaves starting early in the season.

Scab that occurs on the shucks during fruit development can impact the size of the harvested nut and percent kernel fill. The impact to overall yield will vary depending on the severity of nut scab.

How to manage this disease?
The fungus likely overwinters in the orchard on the tree, in the leaf litter, or on the shucks. These reservoirs of the pathogen can be the source for the coming growing season. You may be able to reduce these pathogen reservoirs by removing orchard floor debris.

Pecan scab can also be managed using cultural practices such as thinning and pruning, which help with airflow throughout an orchard.

The last thing to do is plant resistant cultivars. Mandan, Lipan, Amling, and Cape Fear are four cultivors resistant to pecan cab advised for North Carolina.

Submitted By Anass Banna, Caswell County Smalls Farm Agent