Bad pecan nuts

Asked February 24, 2016, 2:39 PM EST

Why am I getting what appears to be rotten pecan nuts? When the pecan nut is cracked opened, the inside is dark/blackish and crumbly. Our trees (2) are appx. 10yrs, what can we do??

Giles County Tennessee

1 Response

The cause of the physical appearance of the pecan nut is most likely due to a fungal infection called pecan scab. Scab is the most prevalent and challenging disease where ever pecans are grown. Pecan scab typically infects both the leaves and nut shucks (the protective shell or husk around the nut), especially when they are young and actively growing in the early part of the growing season. The greatest scab damage occurs when the nuts become infected. Early-season infection can significantly reduce yield and quality. This is a weather related disease, because with more rainfall and increased hot, humid conditions, the disease will become more severe. However, if the weather is dry with only minimal rainfall and less humidity, the impact of the disease will be significantly less. The best way to reduce the overall impact that pecan scab will have is to plant scab-resistant pecan varieties. A very effective, but for homeowners not very feasible, means of controlling scab is a preventive fungicide spray program. It is critical to begin fungicide applications at bud break to prevent early scab infection. A continuation of sprays based on the label directions, weather, and rotating three different fungicides from nut start to maturity is recommended to mitigate this problem. Therefore, on average one can expect to make approximately 12 spray treatments during each growing season. In addition, thorough coverage of the entire tree canopy is very important, which makes spray treatments impractical for the homeowner.