Problems with herbicide-resistant weeds persist throughout the country and appear to be more prevalent than ever. Given this, growers need to be mindful of what they’re doing to address future weed management issues.
It’s also important for growers to remember there’s a danger in becoming too reliant on past weed control approaches and simply going with the status quo from year to year. This is why a good weed control program involves ongoing assessment, as well as the flexibility to make changes as needed.
“Even if weed management programs are working, finding ways to continue success while changing the program are vital to a diverse system, which helps with overall sustainability. If a farmer uses the same system too long, it will eventually fail, even if it’s working really well right now,” says Vince Davis, a cropping systems weed scientist and Extension specialist for the University of Wisconsin-Madison.
But reviewing weed control programs isn’t just for farmers with row crops, according to William Halleran, an agronomy specialist and county program director with University of Missouri Extension. Weeds can also negatively impact cattle grazing on pastureland, or hay and other forage crops.
“If 30% to 35% of your field is non-consumable forages, you need to determine how to eliminate [them] from your field,” says Halleran. “And one of the first things to do is determine whether or not [the problem] can be addressed chemically.”
Building a strategy
According to Halleran, deciding whether to enlist the help of others to combat weeds or do it yourself is also a part of the evaluation process. Either way, though, some type of planning and strategy is needed to get the most out of your weed control efforts.
“With training and education, farmers can handle the do-it-yourself approach, but you’ve got to be careful and do regular and routine maintenance, because the ‘good old boy, aw shucks’ attitude scares me when people are applying chemicals,” Halleran says. “You need to read directions and follow them, not only for your own safety, but for the health of your fields.”
Like Halleran, Davis also advises the do-it-yourself approach to weeds might not be for everyone, especially given the number of changes that occur each year when it comes to resistance issues, crop traits, herbicide names and more; but having someone else take the lead on your weed control program still requires your input and oversight.
“For anyone with little interest, or little time to stay on top of these changes, constantly changing and designing new weed management plans on an annual basis can be a daunting task,” Davis says. “However, outside professional help won’t be able to make good decisions if they don’t have the information related to previous weed problems and late-season escapes associated with some fields.”
This is why Davis stresses that successful weed control programs need to be integrated with the agronomic practices being used for each field. In short, plans for crop rotation, tillage, manure application, harvest times and more need to be evaluated, communicated and factored into your annual weed control efforts. However, doing all this still doesn’t guarantee success.
Adapt, adopt, improve
According to Davis, weeds have demonstrated over time an ability to adapt to our practices and take advantage of “environmental niches.” Because of this, he indicates there’s really no system that will control weeds forever, which makes them a continuous threat to sustainable agricultural production.
“Given the increasing cost of farming and the pressure to produce good yields in a sustainable way, farmers must take weed control seriously to increase diversity in the management system and avoid occasional crop production failures. However, even if what a farmer is doing now is working fine, it’s practically guaranteed it won’t stay that way,” explains Davis.
All of which reinforces the fact that there’s too much money to be made (or lost) to not assess weed control programs every year and determine whether or not changes need to be made.
“It’s going to cost them [farmers] money if they don’t take weed control seriously, as there’s too much money spent on fuel, seed and equipment to ignore problems,” Halleran adds. “Weeds don’t make you money ... things are too expensive to be growing corn and weeds.”
- Yontz writes from Urbandale, Iowa.
Ask the right questions for weed control success
"Junk in, junk out” is a saying commonly associated with computer programs. But it also applies to weed control programs, as the success of any program depends, in part, on the quality of information used to decide what actions need to be taken to combat weeds.
This is why experts like Vince Davis, a cropping systems weed scientist and Extension specialist for the University of Wisconsin-Madison, recommend growers keep detailed notes on every field and then use the information to plan for future planting cycles.
Given this, Davis offers the following as examples of key questions every grower should ask (and answer) regarding their fields at the end of each season as they prepare for the next growing cycle:
Why are weeds present at the end of the season?
Where, specifically, are the weeds present (wet areas, areas with a failed stand or poor canopy, areas where manure was spread, areas where the sprayer skipped, just random areas)?
What are these weeds, and are they a species that’s difficult to control with the herbicide program used in that particular field?
Is this weed species one that has commonly become resistant to the herbicide being used for postemergence control?
Is it a species that germinates late and likely came after the spray application?
By asking these types of questions and gathering the necessary information to address them, a grower will have a much clearer picture as to what his or her plans should be for each individual field in future crop years. Simply put, being able to look at your fields objectively and assess them accurately is an important part of developing a successful weed control program.
“Weed management plans should be adjusted every year to ensure they are diverse. So, the more information a farmer gathers and deciphers in the fall during harvest, the better those adjustments can be,” Davis says.
Solution Center is independently produced by Penton Farm Progress through support from SureStart ® II herbicide. For more information, visit GetMoreTime.com.
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