By Clint Thompson
Weather conditions are ripe for scab disease to flourish in pecan orchards across Georgia and Alabama.
That’s not surprising but still disappointing for pecan producers in both states who are trying to produce a crop this year. But it’s the reality, especially after last week’s spike in rainfall attributed to Tropical Storm Arthur. It brought increased moisture and flash flooding in some areas.
Lenny Wells, University of Georgia Extension pecan specialist, talked about the resulting spike in scab disease pressure in an interview with AgNet Media.
“It creates a ton of pressure and then also it makes it really hard to keep them covered because you go out there and spray in the morning, you get the rain in the afternoon and you’ve got to tighten your schedule up. I mean it’s raining some every day and it really makes it hard to keep them covered,” Wells said.
What is Scab?
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, like what was experienced last week. Some growers must make at least 10 fungicide applications during an average year to manage the disease.
“Pretty much everybody’s dealing with the same problem right now. And it just comes at a bad time for pecans, too, because those nuts are starting to size,” Wells said. “You spray them and then they grow some, and then you got new unprotected tissue there. The more pressure you’ve got, it’s that much harder to control it.”
Overuse of Miravis
There’s added concern that growers are overusing Miravis Top. Wells stresses that Miravis Top and Miravis Prime be rotated with Dodine or Dodine/Tin. Producers are cautioned against using any Miravis products back to back.
“It’s a great product and we want them to use it, and we want it to continue to be effective. I saw a lot of people this year kind of start to use it earlier than I would have liked to have seen because I’d like to see us save it for nut scab, when those nuts are really sizing. That’s when you get the best, the most benefit out of it,” Wells said.
Wells said the producers are limited to four sprays in a given season, per the registered label. But he advises no more than three applications.
“Given some of the potential issues we see out there with potential resistance development down the road, I think if you can limit it to three, I would do that,” Wells said. “I mean, it’s a great product and we want to keep it in the in the rotation, because it’s really the best thing we have right now for nut scab and rotating that with the Dodine and Tin combination, that’s kind of our bread and butter when it comes to nut scab.”