When herbicide resistance is confirmed on farm, we often think only of the increased herbicide costs. There are a number of other costs growers might incur, however. These can include:
- Crop yield loss
- Reduced commodity prices due to increased dockage
- Reduced land values
- Costs of mechanical and cultural control measures
- Changes to crop rotation
All things considered, the cost of proactively implementing herbicide resistance strategies is lower than the cost of managing reactively. This requires a different approach to weed control.
In some cases, non-chemical (cultural) management may be required, such as the strategic use of tillage, increased seeding rates, weed seed destructors, etc. When it comes to herbicides, layering products offers the best means of control.
What is herbicide layering?
Herbicide layering is the practice of using multiple herbicide groups and active ingredients, at different application timings, to control the same resistance-prone weeds.
In practice, herbicide layering means starting with a pre-seed herbicide application that includes both a burnoff and extended weed control product. The burnoff product controls the emerged weeds, while the residual activity of the other herbicide product keeps weeds from germinating during the vital early weeks of crop development.
Afterwards, a post-emergence application containing one or more herbicides with different modes of action can be used. In total, two, three, or even four unique modes can be more strategically applied throughout the season.
Keep an eye on the forecast
Variable environmental conditions can impact how effective herbicide layering can be, however. As a result, having a well-planned early weed control program is critical. Learn more here.
Spraying during warm and sunny daytime conditions, and when nighttime lows don’t dip below 4° Celsius, is the best overall strategy. This is particularly true when trying to control larger perennials and winter annuals. The more receptive weeds are the better, so if weeds have been damaged by frost, try and hold off. If weeds are damaged by frost or not actively growing, they will not metabolize the herbicide properly at the site of action. The end result of this can be opening the window to herbicide-resistance development and overall lack of weed control.
When using a soil-applied herbicide that requires a rainfall for activation, try to time your extended weed control application just prior to moisture accumulation to ensure the herbicide is washed off the crop trash and moved into a soil solution for germinating weed uptake.
Look for flexible, powerful products
Overall, having a well-planned early weed control program can really support profitability. Here are proven FMC Canada products that fit the bill.
PrecisionPac® CF herbicide provides effective, quick burnoff of hard-to-control weeds, all with the customizable package size and rates that make PrecisionPac® herbicides unique. This Group 14 herbicide also controls glyphosate-resistant biotypes and has a low use rate for application in a broad range of crops. With multiple rate and tank-mix options, you get the best agronomic fit for your weed spectrum and timing.
Before planting, add either PrecisionPac® NC-0050 herbicide or PrecisionPac® NC-00439 herbicide to your glyphosate burnoff program. Both blends provide complete systemic activity to incinerate your toughest weeds to the roots and prevents re-growth. Narrow-leaved hawk’s-beard, volunteer canola and dandelions don’t stand a chance. Another pre-plant option is PrecisionPac® DB-878 herbicide with its multiple mode of action and control of weeds like kochia and wild buckwheat.
PrecisionPac® DB-878 PRO herbicide can be sprayed ahead of wheat and barley. Get trusted kochia control without sacrificing extended control on cleavers, dandelion, narrow-leaved hawk’s-beard, or volunteer canola.
Not only does PrecisionPac® SZ-75 herbicide control kochia in spring wheat and durum with powerful, extended Group 14 activity, it also has activity on Russian thistle. Get your wheat off to a cleaner start during the critical weed free period with PrecisionPac® SZ-75 herbicide.
With its Group 14 and 15 modes of action, Focus® herbicide provides extended control of a broad range of grassy and broadleaf weeds, helping create a weed-free period for your crop to thrive at a critical point in the growing season. The early-season weed control also gives you more flexibility to complete your in-crop applications in other crops.
PrecisionPac® herbicide blends can also play an important role in resistance management programs by combining multiple modes of action and delivering strong control of key weeds throughout the season.
PrecisionPac® PP-2525 herbicide delivers consistent in-crop weed control in wheat (spring, durum and winter), barley and oats. This blend controls a wide spectrum of weeds including narrow-leaved hawk’s-beard, hemp-nettle, redroot pigweed, cow cockle and volunteer canola, while offering tank-mix and re-cropping flexibility across major soil zones.
For fields where perennial and biennial weeds are a concern, PrecisionPac® PP-23235 herbicide provides premium performance in the black, dark brown and grey-wooded soil zones. It delivers leading control of weeds such as round-leaved mallow, night-flowering catchfly, scentless chamomile and white cockle, along with suppression of Canada thistle in wheat and barley.
When grassy weeds are also part of the challenge, PrecisionPac® CS-100-2525 herbicide provides tailored one-pass control of both grassy and broadleaf weeds in spring and durum wheat. This blend delivers strong performance on weeds including Group 1-resistant wild oats, Japanese brome, dandelion and narrow-leaved hawk’s-beard.
Similarly, PrecisionPac® CS-100-23235 herbicide combines pyroxsulam with PrecisionPac® PP-23235 herbicide to deliver uncompromising control of grassy and broadleaf weeds in the dark brown, black and grey soil zones. It offers growers an all-in-one solution for challenging wheat fields where both weed types need to be managed together.