With what seems like constant pressure from corn rootworms, more Southern growers are using in-furrow and band insecticide treatments for early control followed by a later aerial application to finish the job.
In-furrow and band treatments of liquid pesticides in closed-type systems are designed for user safety. But they're effective and cost-efficient, too, says Brent Clark, Dumas, TX.
"We've used a T-band program four years and had good luck with it," says Clark.
He needs good rootworm control because of his irrigated corn-after-corn program.
Following harvest, he plows the field twice, then runs a ripper. Anhydrous ammonia is applied in winter or early spring. At planting, Clark applies Aztec insecticide via a John Deere MaxEmerge closed system.
The chemical, applied at 7-8 lbs/acre, flows through microtubes to a T-band attachment. It's applied in a 7" band and in-furrow.
"I like the closed system because there is less chance of getting chemicals on your skin," says Clark. "Plus, we get pretty good control."
When rootworm pressure increases due to an erratic hatch, he comes back with an aerial application of Furadan in early June.
He warns that it's essential to stay on top of rootworms and other insects.
"Mites used to be our biggest problem; now it's rootworms," he says. "You have to check for them every day or so, then be ready for a late treatment."
Paul Caraway, also of Dumas, shares that opinion. In his corn-on-corn program, he uses Counter at 7-8 lbs/acre.
"We band on the pesticide with our vacuum planter," says Caraway. "The chemical is put down about 1" above the seed. We wish that would give us full-season control, but it usually doesn't. So we have to come back with a post aerial application of Furadan."
Caraway has used Furadan in-furrow in the past and saw some good results early on. But he prefers the banding program.
"The Furadan seems to work better for the later rootworm problems," he says.
The banding treatments cost Caraway and Clark about $20 per acre. Each aerial application costs another $20 per acre.
Jon Tollefson, research entomologist at Iowa State University, says it's as important to protect young plants from the rootworm larvae as from the adult insects. In Iowa State studies from 1992 to '96, various in-furrow or banded treatments provided good rootworm larvae control and solid root ratings. Several were 80-90% effective in keeping root ratings low.
"For no-till corn, in-furrow works better at controlling the larvae (because it's applied below the residue)," he points out.
Fortress showed good results with both in-furrow and T-band applications, as did Aztec, he reports. Good results also were achieved from in-furrow and banded treatments of Lorsban. Counter showed good results in band applications. Thimet is approved only for banding and showed good control, says Tollefson, while Furadan demonstrated strong control in postemergence applications.