Growers should plan ahead for energy beet production
Farmers considering energy beet production in the future should assess what herbicides they use during this growing season due to potential residue impact.
"Many growers across North Dakota are looking hard at a new industrial crop called energy beets, which are sugar beets bred for the biofuel market and industrial purposes such as high-value chemicals," says Mohamed Khan, a sugar beet specialist at North Dakota State University. "Even if producers don't plant energy beets for a few years, they should be mindful of what herbicides they use on their crops this year. Several common herbicides may carry over and cause injury to the beets two or three years after they are applied."
While the use of genetically modified (Roundup Ready) seeds can reduce the need for chemicals, sugar beets are sensitive to certain herbicides, so it is important to assess herbicides used in previous years when selecting fields for energy beets.
"Herbicides applied to other crops, especially corn and soybeans, have a long rotational restriction," Khan says. "As a group, ALS-inhibiting herbicides tend to have the longest rotation restrictions for energy beets (up to 40 months), plus a successful bioassay (measuring the effects of a substance on a living organism.) Also, products containing sulfentrazone, atrazine, Sonalan, Treflan and Prowl have rotational restrictions of 24 months or longer for energy beets. For example, Spartan has a rotational restriction of 36 months."
Growers should pay attention to the crop rotation restriction of each active ingredient in premixture herbicides. For example, Extreme has a 40-month rotational restriction, plus a successful bioassay, for energy beets because it contains imazethapyr (Pursuit) as one of the active ingredients.
Growers should contact a chemical dealer or the county NDSU Extension Service agent for suggestions on what chemicals can be used to avoid affecting a future energy beet crop while still controlling weeds in their current corn or soybean crop.
"Effective herbicide strategies exist where sugar beets, corn and soybeans are traditionally grown in common rotations up and down the Red River Valley," Khan says. "Recommendations are available from private and public specialists. Also, growers should pay attention to proper sprayer cleaning and check for drift and/or the volatility of herbicides."
To learn more about herbicide carryover, go to the "2013 North Dakota Weed Control Guide" and refer to Table Y15 on ages 112 to 114. The weed guide can be found at http://tinyurl.com/weedguidecarry. ALS-inhibiting herbicides are Group 2 herbicides and described on Page 108.