What is in this article?:
- Heavy rains swamped pecan orchards all summer and left them vulnerable to the crop's No. 1 enemy: scab.
- Scab is reported to be the worst in decades in some locations where growers had a difficult time getting into orchards to apply fungicides.
- Before the scab outbreak, Georgia expected 80 million to 90 million pounds this harvest, but disease might claim 15 million pounds or more of that.
PECAN'S No. 1 enemy, scab, flooded pecan orchards throughout Georgia this summer. Growers in the country’s leading pecan-producing state scrambled to get into orchards to apply timely fungicides to stay ahead of it, but it will cut yields this year.
Nuclear year for disease
Getting ready for a Florida pecan grower meeting in early September, Tim Brenneman pulled a picture of a nuclear bomb explosion up on his computer screen. Said he was going to start his presentation on the 2013 pecan year with that picture to describe what scab has been this year. “It’s been a nuclear year as far as scab explosion,” said the UGA plant pathologist based in Tifton, Ga.
“A year like this will show weaknesses in the system. I think we do a good job on scab control, but in a year like this one growers can see what isn’t working,” he said.
For example, on his travels around the pecan-growing region in Georgia it is not hard to see how well or bad spray coverage has been for fungicide treatments. Many locations have scab prevalent in the upper canopies where spray booms didn’t reach.
Pecan growers have good chemistries to fight scab with several modes of action, including strobilurin, triazole, triphenyltin hydroxide, organotin. Plus, an old tried-and-true chemistry called dodine is once again working on scab in Georgia, where growers stopped using it many years ago because it had lost some effect on the disease. But it seems to be working again, especially in combination with the other chemistries.
Brenneman is now working with a new chemistry that is not yet labeled for pecans, but he says it “shows great promise” in fighting the disease and hopes it will soon be labeled for pecans.
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