Mr. Ken Kirkland from the Scott Experimental Farm was one of the scientists updating us on new developments in weed management at our annual conference. What's new ranges from: new ideas about using old herbicides to new weed killers, herbicide tolerant canola, and non-herbicide related ideas such as late fall seeding of spring seeded crops. Some of these ideas you or your neighbour could be using next spring so take note!
One new use for old technology is the non-incorporated use of incorporated granular herbicides. In a three year direct seeding study at Scott non-incorporated Treflan, Avadex, and Fortress reduced wild oat growth as much as on plots where these products were incorporated. Yields of cereals were higher in the non-incorporated plots because of increased water conservation. Yields of oilseeds were slightly lower but Kirkland attributers that to poor seed placement. As some producers already have experienced, it looks like non-incorporated use of these products and Edge might have a good fit for direct seeders. Watch for product registrations!
Another new registration for Roundup is preharvest control of dandelion. Kirkland cites Monsanto's data which found 87% dandelion control 10 -12 months after a 1 liter/ac. preharvest application (control ranged from 75 - 95%). Also of interest is Monsanto's report of 84% control of dandelions less than 15 cm in diameter following a preseed or post harvest application of 1 liter/acre. If these results are consistent it will be good news for direct seeders with dandelion problems.
New chemistry coming for weed control includes Horizon which has already received registration. It takes out wild oats and foxtail in wheat and has a good number of tank mix options. Attain put out by DowElanco has not yet received registration. It looks like a good option to control cleavers in the cereal years of your rotation. BASF has a green foxtail product in a new group for herbicide resistance problems. It is to be used in wheat but is not yet registered.
Kirkland lists some interesting rotational techniques that might be useful to direct seeders. Always seeding crops with similar days to maturity can lead to creating a niche for certain weeds. Including a polish canola or barley in a rotation of wheat, peas and argentine canola can disrupt the formation of this niche growing situation. Fall seeded crops can be very useful rotational tools to combat weeds. They are very competitive and start growing very early so they require significantly less herbicide inputs. To take further advantage of this concept research is being done on late fall seeding of spring crops. Results from two years of fall seeded Argentine canola at Scott look promising. Round up tolerant canola could have a very good fit if fall seeded canola works out.
Although some of these techniques are still at the experimental stage, most direct seeders welcome new concepts in weed control. Watch for them at informational meetings and summer tours so you can make wise evaluations.