By Clint Thompson
Scab is not the only disease impacting pecan orchards in the Southeast this summer. According to Lenny Wells, University of Georgia Extension pecan specialist, anthracnose has been observed on some pecan leaves this year.
“We’ve had a few calls on that this year and did get confirmed in the diagnostic lab that it was anthracnose because there’s several things that you can see; kind of some leaf scorching on that can cause that. But we did get some confirmed anthracnose popping up already in some places,” Wells said. “This hadn’t been terribly bad. And I think a lot of that, I think a lot of the reasons it’s not worse is because of the phosphite that we’re using now early season for leaf scab. I think that’s helping a lot.”
Wells noted in the UGA Extension Pecan Blog that anthracnose symptom expression is latent, meaning the infection occurs weeks prior to symptom develop. Once a grower observes symptoms, it is too late to treat for it. Wells said the best products for anthracnose are group 3 fungicides, though the disease can still be seen given the right environmental conditions when the products are used.
“Diseases like this often come in when we are trying to stretch out scab sprays,” Wells wrote in the blog post. “Bear in mind that although you may see anthracnose in an orchard, it would likely be a lot worse without the use of these products.”