Costly Input: UGA Extension Pecan Specialist Discusses Scab Spray Expenses

Clint ThompsonGeorgia, Pecan

By Clint Thompson

Fungicide applications are one of the most important and costly expenses that pecan producers must make. If they can’t or won’t protect their crop from scab disease, yields will be drastically reduced.

Photo by Clint Thompson/Lenny Wells speaks at the UGA Pecan School in Perry, Georgia, on March 20.

It is a message that Lenny Wells, University of Georgia (UGA) Extension pecan specialist, emphasized during the UGA Pecan School on March 20 in Perry, Georgia.

“Scab is certainly one of the biggest factors we’ve got limiting production,” Wells said. “Certainly, with scab, that’s going to drive up the cost of production.

“If you’ve got a variety susceptible to scab, then you’ve got to spray a lot. There are still costs even if you’ve got a resistant variety. One of the keys is having varieties that have a higher yield potential than what we’ve had in some of the older varieties. We’re seeing that out of several varieties now, and that’s what we’re pushing.”

Scab is a fungal disease that infects the leaves or nuts of pecan trees. If scab impacts the nut early enough in the production season, it can cause the nut to blacken and fall from the tree. It excels on trees that have received moisture. Some growers must make at least 10 fungicide applications during an average year to manage the disease. The excessive rains during the summer means more applications are needed for a crop.

That’s why UGA recommends farmers produce varieties with some level of scab resistance and decrease the number of fungicide applications required.

“Scab resistance, there’s varying degrees to that. The older varieties that are really scab susceptible like Desirable, even Pawnee, you may have to spray those 10, 12 maybe even 15 times some years if it’s really rainy,” Wells said. “We need varieties that we can grow, spraying at most six or seven times, preferably three to five. We have varieties that we can do that with.

UGA Recommendations

“Probably the three main varieties that I would consider planting right now would be Avalon, Lakota and Creek. Lakota and Avalon have the best scab resistance of those three, but you can probably still grow Creek with four or five sprays, most places. All of three of those have really good yield potential. Instead of 1,000 pounds per acre, you’re looking at 2,000 pounds per acre, is what you’re shooting for.”