Back off broadleafs. New season-long broadleaf weed and grass control is now approved for field corn and corn grown for silage.
Corvus from Bayer CropScience is a selective herbicide that can be applied from burndown through early postemergence and the two-leaf collar (V2) stage.
Corvus is actually a prepackaged herbicide mixture that contains Balance Flexx, a bleacher that inhibits the HPPD enzyme in plants, and thiencarbazone, a new ALS-inhibiting herbicide.
Corvus provides control of more than 50 annual grasses and broadleaf weeds, such as Palmer amaranth, waterhemp, woolly cupgrass and yellow foxtail.
"With rapid burndown and residual activity, Corvus works especially well in no-till and minimum-tillage programs," says Jeff Springsteen, Bayer CropScience product manager for selective corn and soybean herbicides. "Corvus provides long-lasting residual control by translocating through the roots and shoots of weeds."
The soil-applied herbicide activates with rainfall, which moves it into the first few millimeters of the soil profile and into weeds as they germinate. It is reactivated by ½" of rainfall, even after a dry period. This WeatherShield feature makes the product less sensitive to random and sporadic spring rains and enables it to keep on controlling weeds up to 2" in early season corn.
"In our 2008 trials, Corvus was very competitive during the rainy season," explains Brent Philbrook, Bayer CropScience new products development manager.
An exclusive Crop Safety Innovation (CSI) safener is also part of the package. This safener has both soil and foliar uptake, which makes it active in both pre- and early post applications. The company says this changes the capacity of the corn plant to better withstand herbicidal activity and can lead to increased root growth and plant health. Atrazine (where permitted) is recommended as a tank-mix partner to enhance control of cocklebur, giant ragweed and morningglory. For burndown prior to crop emergence, herbicides, such as glyphosate or 2,4-D, can enhance the control of perennial weed species.
On light soils with lower organic matter, Corvus is used at a rate of 5.6 fl. oz. per acre. On coarse soils with less than 2% organic matter, the rate is 3.3 fl. oz. per acre.
A PAT Answer to Test-Driving New Hybrids and Varieties
Ask soybean yield champ Kip Cullers for advice and he'll give you a "PAT" answer. PAT stands for Product Advancement Trials—Pioneer Hi-Bred's testing program that puts experimental crop genetics into farmer fields two years ahead of commercialization.
"It doesn't cost you any more to use the right numbers [varieties] in a field, but it can cost you a lot to use the wrong ones," Cullers says. "Thanks to my PAT plots, by the time most growers are planting a variety, I've already had several years of experience knowing where and how it fits on my farm."
Mike Hellmer, Pioneer technical services manager based in Bloomington, Ill., says PAT products don't even have an official number when they are planted in grower's fields. The company takes breeding materials to local areas to see how they will perform in certain geographies. The company's agronomists may be looking for a specific soil type or tillage system to test.
The program reflects Pioneer's strategy to test numerous experimental soybean varieties and corn hybrids in local environments. The corporate motto is "the right product on the right acre." Pioneer agronomists advance experimental products to commercial status for their area.
The PAT program is open to growers who are willing to accurately plant and harvest the plots. Cullers admits that part is a "pain," but "totally worth it." Most PAT test plots include 12 to 15 different products. Each product is tested in six to eight rows that are 500' to 1,000' long. Hellmer says the company increased the number of PAT plots in 2008 and will substantially increase the number of plots again during the 2009 growing season because of the increased need for localized testing.
Farmers interested in testing new genetics should contact their Pioneer account manager or regional agronomist. "We are actively looking for good growers," Hellmer says. "The PAT testing program is a benefit for us and the grower, as it helps us fit our best products to the appropriate growing areas."
- March 2009