Review of a Few New Herbicides for ‘06 Weed Control

There are a few more options than in years past, but most are still pre-mixes of other existing products put together under a new name. The encouraging thing is that it gives more options in the marketplace for certain crops. With all the crop protection products coming off patent now, there are many “names” for the same old active ingredients, so knowing what is in the product and the ratio becomes more important. Here is my biased opinion on some of the products and how they fit into your spray acres.

Rimfire (Bayer Crop Science) is a wild oat product that has some foxtail activity. It is a combination of Silverado and Olympus and has a pretty good window of application, from 1 leaf up to flag leaf emergence. There are lots of broadleaf tank-mixes you can use with it and the use rate is very low. Some advantages I see with the product are that it has residual control, a great safener built in and is in the ALS mode of action. The mode of action is important if you are concerned about selecting for resistance to ACC-ase chemistry like Puma or Poast. It won’t fit on all acres, as it controls mainly wild oat and most other grasses are listed as partial control. The label currently has its rotation set to 12 months or longer, depending on crop. Rimfire will also require an adjuvant, with either an MSO or basic blend surfactant being the most common.

Affinitiy BroadSpec (DuPont) is a tweak on Affinity TankMix, adding more Express and taking some of the Harmony GT out. Its fit will be in areas that need more Canada thistle control and will be very specific if tank-mixing with grass control products. Kochia will still be its weakness, but that can be managed.

Another clethodim is the upgraded Select Max (Valent), with “inside technology,” meaning better uptake to the growing point for weed control. The formulation is somewhat different, thus affecting the rate that is used. The data looks pretty good as far as uptake and control with the product. The thing to get a handle on is the use or non-use of adjuvants in certain situations. Certain situations call for the use of either a surfactant or an oil, and in some cases none is needed.

Cleanwave (Dow AgroSciences) is targeted for use in Montana, Wyoming and west of the Missouri River in South Dakota. Kochia (up to 8” tall, including ALS and dicamba tolerant kochia) wild buckwheat, lambsquarters, and prickly lettuce are among the target broadleaves.  It can be tank mixed with grass control products and will need some MCPA, 2,4-D, or SU chemistry to round out its broadleaf weed control spectrum. One thing to watch with this product is crop rotation intervals.  Some rotation crops are in a 18-month restriction, including field pea, soybean, and sunflower.

Starane NXTcp (Dow AgroSciences) is a co-pak of Starane and Buctril giving it two modes of action (fluroxypyr + bromoxynil). Kochia, wild buckwheat, lambsquarters, and Russian thistle are among the target broadleaves. There are no rotational crop restrictions, and according to Dow, it has excellent crop safety, a wide window of application, and is tank-mix compatible with grass herbicides. The product will still need some tank mix partner for mustard and pigweed, (Everest or Rimfire would help) or either Affinity, MCPA or 2,4-D. It does not have the Canada thistle control that Widematch does. Dow also points out that it will not control large weeds (best control annual weeds 2 to 4” tall), is very sensitive to rate cutting, and can antagonize grass control with Puma.

Axial (Syngenta) is a new introduction into the wild oat and foxtail market for wheat and barley. It is an ACC-ase product, but called a “den” instead of a “fop,” like Puma, or a “dim” like Select. The data from this past year has been very good, even in resistant wild oat areas. One thing I would say is that the control numbers are very consistent in university trials. It has a surfactant called Adigore that comes with the Axial to use. There are many broadleaf options to mix with it and the window of application is from 2 leaf to boot stage for wheat or barley. I still think it’s a good idea to rotate herbicide modes of action, so just be careful when thinking about your chemical rotation.

For corn, Resolve (DuPont) isn’t that new, as it is the same active ingredient as Basis. But the use of Resolve in front of Roundup Ready corn as a pre-emerge or early post burn-down is attractive. Mainly that attractiveness comes from the price point, but also in that it should get a grower potentially out sooner on corn, taking advantage of the residual affect Resolve has. Corn yields suffer when there is early weed pressure, so it might pay to look into this one.

There are so many products promoted this time of year that it can be hard to distinguish hype from reality. Be aware of what works best under the conditions that are going to be present at, before and after spraying takes place. There are many more products that could have been discussed. Get to know their mode of action, rotation restrictions, and conditions they work best in. The name of a product is not nearly as important as the performance. Keep the adjuvants in mind too, which can make or break product performance. You can review my take on adjuvants online at www.smallgrains.org/springwh/May05/hanson/hanson.htm. 

Your local agronomist is an excellent resource for herbicide recommendations. Another excellent resource is the NDSU Weed Control Guide, available in print from county extension offices and online at www.ag.ndsu.nodak.edu/weeds.

Hanson rocks and rolls as a certified crop advisor near Devils Lake, N.D.