Wheat is very sensitive to competition from weeds, both broadleaves and grasses. One study showed every ryegrass plant per square yard reduced wheat yields by 0.4%. Although competition from all weed species is not as detrimental to wheat as Italian ryegrass, wheat yields in general are extremely susceptible to weed competition.
The best defense against weed competition is always a strong, vigorous crop that will establish stand and canopy quickly. Even with the hardiest, most vigorous crops however, growers can still protect their crop from weed competition using two products offered by Corteva Agriscience, Quelex and Rezuvant. Both premix products are powered by the growth regulator Arylex active to provide advanced broadleaf weed control with Rezuvant also providing control of tough grasses including Italian ryegrass. Arylex active (group 4) provides an alternative mode of action to the market with excellent crop safety.
The most common and troublesome broadleaf weeds in the South’s winter wheat are common and mousear chickweed, henbit, and wild radish. With its favorable rotation interval to soybeans, Quelex herbicide has become the standard for control of these and many other broadleaf weeds regardless of the timing or temperatures. The premix formulation of Arylex active and the ALS inhibiting florasulam, offers unmatched broadleaf control as well as a tool to help growers fight the buildup of weed resistance. Weed resistance is naturally occurring and selected for by the repeated use of an herbicide with the same site of action year after year. With a dual site of action product like Quelex, growers can help prevent that selection by utilizing multiple sites to control troublesome weeds.
To maximize the efficacy offered by Quelex, growers should pair Quelex with a crop oil concentrate such as FS Optivix. Quelex can be applied with liquid nitrogen fertilizer as the carrier and should only be paired with a non-ionic surfactant, such as FS Talent, in these cases.
Rezuvant, also powered by the growth regulator Arylex active, has an additional role to play in winter wheat weed control, controlling Italian ryegrass. Rezuvant, a premix of Arylex active (group 4), fluroxypyr (group 4), and pinoxaden (group 1), offers cross-spectrum control of broadleaf and grass weeds. The inclusion of pinoxaden adds strong control of Italian ryegrass to the standard of broadleaf weed control that is Arylex active. As one of the most economically important weed species in small grains, Rezuvant’s protection against Italian ryegrass is vital to a successful wheat crop.
Rezuvant is yet another tool in the battle against broadleaf weed resistance as even though the premix includes two group 4 growth regulators, each active attacks weeds at different, unique target sites in the plant. Like Quelex, Rezuvant can also be applied with liquid nitrogen though it should be limited to no more than 50% of the carrier volume and no more than 30 lbs of actual nitrogen per acre.
With flexible application timings from 2-leaf to flag leaf, Quelex and Rezuvant are two of the best options for winter wheat weed control from Corteva Agriscience’s comprehensive cereal herbicide portfolio. With the unparalleled broadleaf control of Quelex and the combination of broadleaf and Italian ryegrass control by Rezuvant, these two products can help protect a growers entire crop from weed competition.