Follow these guidelines to prevent herbicide-resistant weeds
Mississippi farmers are no strangers to herbicide-resistant weeds. During this planting season, farmers should keep in mind some important practices to prevent weeds from robbing yield.
The first step is to have a diverse weed-management approach that not only takes into account the type of herbicide resistance but also the weed’s biology. Paying attention to both of these factors is essential to maximizing yields. Planting might be top of mind now, but it’s important to control weeds present in soybean fields year-round, including before planting, at planting, after emergence and after harvest.
Once seed is in the ground and plants start emerging, scouting early and often after applying post-emergence herbicides will reveal whether any resistant weeds survived. If you spot resistant weeds, make sure to eliminate them. Allowing troublesome weeds to survive can accelerate the shift in weed populations that favors problematic, difficult-to-control weeds. What’s good for crops can be bad for weeds.
Maximizing crop competitiveness can slow weed emergence and growth and lessen the weed’s reproductive ability, which is critical to reducing the risks of herbicide resistance. Consider the following practices to give crops the competitive advantage against weeds:
- PLANTING DATE
Crop planting date can affect the severity of a weed infestation. Rapid and consistent emergence of
the crop is critical to its success and competitive advantage over associated weeds.
- ROW WIDTHS
Narrow row widths can accelerate canopy development, which slows annual weed emergence and
diminishes their ability to compete with crops. Over time, this results in
fewer weed seeds in fields.
- SEEDING RATES
Like row widths, increased seeding rates can increase crop competitiveness and
accelerate canopy development.
- CROP ROTATION
How does crop rotation make a difference? Rotating different crops allows for different herbicides
with different modes of action, different planting dates and different production practices – differences that add up. Crop rotation optimizes crop competitiveness at the expense of weed growth and reproduction, which can delay the evolution of herbicide-resistant weeds.
- SEED SELECTION
Choosing the right seed can help suppress weeds. Weed suppression can be attributed to
crop emergence and growth rate, height, leaf angle and canopy formation.