Don’t Wear Blinders Concerning ResistantWeeds
The subject of this column, three years ago (May 2009), was my advice on whether corn should still be planted this late in May or if you should consider changing to soybeans. What a blessing it is to discuss weed control for this year’s May issue.
Weed control will be different this year than in recent years due to the early, open spring. The warm weather allowed weeds to germinate as early as March and some growers took advantage of the early season to wipe those initial weeds out with tillage. Early planting will make an application of a residual-type herbicide more attractive with a growing season lasting almost a month longer than we’ve recently experienced.
While it is too late for pre-plant and pre-emerge programs, there are good products available to add to your first chemical application, whether RoundupReady or Conventional. Consult your local chemical retailer for what works best in your area.
The reason I’m talking about herbicides this year is the increased, real risk, of losing one of the best herbicide options we’ve ever had available to work with. RoundupReady resistance is now undeniably present in our region. Some 2011 fields had serious weed issues that need to be addressed in 2012 with either alternative modes of action, crop rotation, or increased tillage/cultivation. Because of the number of seeds these weeds produce, the results can be devastating. One resistant Waterhemp plant in 2011, for example, can lead to 2,500 Waterhemp plants in 2012. Those, in turn, can lead to over 6,250,000 in 2013. This shows how fast resistance can spread. So far in North Dakota, we have Kochia, Waterhemp, Common Ragweed, and Marestail all confirmed as resistant to glyphosate.
The option I am most excited about is adding LibertyLink soybeans to your rotation, because I have seen the excellent varieties available for our region. These varieties have the genetics to compete with any of the Roundup Ready 2 Yield varieties on-the-market and they have the agronomic traits to handle the variable soil conditions that exist in our geography. Most of the current lines have great IDC tolerance and some Soybean Cyst Nematode resistance in maturities as early as 0.3. LibertyLink soybeans are a perfect product to incorporate into a corn-soybean rotation and especially into a corn-soybean-sugarbeet rotation that has no small grains in the mix.
Please be proactive on weed resistance this year in order to preserve glyphosate as a useful tool in our weed control program. Residual products, companion products, and LibertyLink are all alternatives you need to be using this season.
