What is in this article?:
- Irrigation proves a necessity this year for Alabama growers
- Little leaf spot
- Bollworm numbers low
• Droughty growing conditions made it easy to distinguish between the “haves” and the “have-nots” of irrigation during the Central Alabama Crops Tour held in mid-August.
AUSTIN HAGAN, Extension Plant Pathologist, left,
and Tom Ingram, Lee County, Ala cotton grower
Bollworm numbers low
Bollworm numbers have been extremely low throughout the summer, he says.
Aphids, says Smith, have not amounted to much in 2011. “They are slow to build and slow to crash. We sprayed some cotton because they peaked in late July, and we didn’t need any more stress on the cotton.”
Stinkbugs are by far the most dominant economic insect pest of cotton in the Southeast, he says. “This is the lightest year for stinkbugs since we got Bollgard cotton. But it emphasizes the importance of a scout, even though it’s almost a single-pest system in the Bollgard cotton.”
Resistant pigweed continues to be the dominant weed problem for cotton producers in the Southeast, says AU Extension Weed Scientist Mike Patterson.
“On the conservative side, you’ll probably spend another $40 per acre once you have this weed in your field. We’ve been working with resistant Palmer amaranth pigweed for five or six years now. Last summer, about 24 counties in Alabama reported having resistant Palmer pigweed,” he says.
Growers who successfully manage resistant pigweed are frontloading with a soil-residual herbicide from burndown all the way through layby, says Patterson.
“But they still have escapes, even after they’ve spent about $60 per acre to manage this one weed. Hand labor sometimes is still required. For the foreseeable future, that’s what you’ll have to deal with. You’ll have to use residual herbicides up front, and it’ll probably cost you at least another $30 per acre to use those herbicides.
“You might have to run a hooded sprayer, applying Gramoxone, in those middles, on the escaped weeds. You may even have to go with something like LibertyLink cotton in the future where we can use Ignite herbicide,” he says.
There’s hope in the future, says Patterson, but it’s still a few years away. “Dow and Monsanto both have genetic technology allowing you to spray over-the-top herbicides that normally are very toxic to cotton.
“Dow has 2,4-D tolerance and Monsanto has resistance to dicamba, Roundup and Ignite. But it’ll be three or four years from now before we’ll see the commercialization of those varieties. For the time being, you have to stay ahead of resistant Palmer amaranth.”