The newest kid on the block, as far as 2002 corn herbicides are concerned, hasn't even moved in yet.
Option, a postemergent corn herbicide that controls grasses and key broadleaf weeds — and offers crop rotation flexibility — is awaiting Environmental Protection Agency (EPA) approval.
“We are anticipating registration of Option in the first quarter of this year,” says Mark Bishop, Option product lead at Aventis CropScience.
Labeled by company officials as a strong second punch after a pre-emergence product such as Balance Pro or Define, Option controls annual and perennials such as fox-tails, barnyardgrass, quackgrass, Johnsongrass and shattercane. It also controls broadleafs such as velvetleaf, pigweed and nightshade.
Recommended use rate will be 1.5 oz/acre along with an external adjuvant system, says Bishop. Once it gets EPA approval, it can be applied on corn up to 20" tall. Its active ingredient: foramsulfuron.
Callisto, the subject of curious advertisements that have appeared in farm magazines, received EPA registration last June. Since then, it has been used on more than 500,000 Midwestern corn acres.
From Syngenta, the postemergent product controls major broadleaf weeds in corn. Developed from a naturally occurring herbicide in the Callistremon citrinus plant, it uses a new mode of action. Its active ingredient: mesotrione.
Callisto, with a postemerge single use rate of 3 oz/acre, typically follows pre-emerge applications of a grass herbicide. It's labeled for application between crop emergence and when corn is 30" tall.
“We recommend applying Callisto early post at the two- to four-leaf stage of corn development,” says Matt Comer, Syngenta brand manager. “While Callisto is effective throughout its labeled range of application timing, Syngenta and university testing show it delivers the best control and greatest value to growers when applied early post. The herbicide's residual activity will keep the field clean up to canopy.”
The product controls broadleaves such as velvetleaf, cocklebur, smooth and redroot pigweed, waterhemp, lambsquarters and common and giant ragweed, including triazine and ALS-resistant weed biotypes. For additional morning-glory and common ragweed control, add as little as 0.25 lb/acre of atrazine to Callisto, Corner adds. It can also be tankmixed with a postemergent grass herbicide.
Valor, from Valent USA Corp., is targeted mainly as a soybean herbicide (watch for soybean herbicide info in our Mid-February issue).
Yet the product can be used in field corn as part of a burndown program with glyphosate or 2,4-D, says Jamie Nielson, Valent market segment manager for Northern row crops. “Either would control the weeds that are emerged, while Valor provides residual control of small-seeded broadleaves that are about to emerge.” Valor helps burn down tough broadleaf weeds such as chickweeds, henbit, Carolina geranium, cutleaf eveningprimrose and mustard species, says John Pawlak, product development manager.
“Valor needs to be applied 30 days prior to corn planting,” Nielson says. “And an inch of rainfall before planting,” adds Pawlak.
It also offers pre-emergence control of chickweed, dandelions, annual nightshades, pigweeds, waterhemp and lambsquarters. Its recommended use rate: 1-2 oz/acres.
From the chemical family N-phenylphthalimide, Valor has a non-ALS mode of action: inhibition protoporphyrinogen oxidase. It also offers rotational flexibility, since it has no carryover, and can be used in multiple tillage systems.
Two new glyphosates and a new atrazine round out this year's corn herbicide lineup. Roundup UltraMax has been added to Monsanto's list; Cornerstone glyphosate comes from Agriliance; and Sipcam atrazine is from Sipcam.