Ag Minute: Alternative Weed Control Methods for Farmers
- Sangamon County News
- Aug 8
- 3 min read
In a world full of changing customer demands, with many consumers now preferring organically certified or non-GMO foods, some farmers have transitioned into producing crops to meet this product demand. Looking at Illinois in particular, organic farmers are producing a traditional rotation of corn, soybeans, and wheat, with oats being an additional crop added if necessary. The 20th Century saw the advent of herbicides able to control any weed that was out there, and almost every row crop farmer chose to go down that path, utilizing a tool that could solve all their problems…for the time being. Unfortunately, many of the same chemistries have been used so frequently now without much crop rotation that some varieties of weeds have become resistant to herbicides. Many farmers are now going back to the shed to pull out their dad or grandad’s old cultivator that was put away on the eve of the herbicide era. This goes for farmers producing organic crops, non-GMO crops that cannot withstand many herbicide chemistries, and traditional GMO crops that now are competing against weeds that may not be killed by glyphosate, glufosinate, or 2,4-D.
For farmers who are able to still spray herbicides, spot spraying technology has greatly eased the burden of respraying fields containing weeds that were not killed in the first (and historically only) herbicide pass after planting. With products from John Deere, Case IH, and AGCO, sprayer booms may now be equipped with cameras backed by AI which prompt the nozzles to only spray herbicides on the exact areas that weeds are detected. This helps farmers save costs on herbicide and sprayer refilling time and reduces the yield loss that can occur from spraying soybeans while they are in their reproductive stage. Recent university publications have highlighted the need for new and perhaps more intensive weed management strategies as a significant amount of resistance has been built to popular herbicides. Take waterhemp (amaranths tuberculatus) as an example. It has been found to have resistance to seven separate herbicide modes of action. Being a weed that can produce up to a million seeds from one plant, it is easy to see how resistance genes can quickly build in a population if there are any plants allowed to reproduce in the growing season.
While a new challenge for conventional row crop farmers, fighting weeds with alternative solutions to chemicals is something that is not new to organic and non-GMO corn and soybean producers. Organic oats and wheat are able to outcompete and smother weeds in organic situations most of the time due to high planting rates, narrow row spacing, and the timing of their growth. However, corn and soybeans are generally planted close in time to young waterhemp, velvetleaf, marestail, foxtail, giant ragweed, and cocklebur weeds emerging from the soil. With the common heat and moisture associated with spring and summer in the Midwest, these weeds have access to the resources they need to thrive, as long as they are able to. Therefore, organic producers have to revert to weed control strategies of old, and some of new. Classic weed control methods include profound amounts of tillage both right before the crop is planted, tillage between the rows called row crop cultivation, reducing row spacing to allow crops to shade out the weeds faster, and using manual labor to walk and hoe entire fields by hand. Novel weed control methods have begun to emerge as well to help meet some consumer demand for organic products as well as aid non-GMO and conventional farmers battling herbicide resistant weeds. One example is an inter-row flamer, which includes a bar and propane tank mounted to the 3 point hitch of a tractor, with burners angled to only scorch weeds between the rows of crops. Another is the Weed Zapper, a product being manufactured by Old School Manufacturing. This method involves brushing weeds that have emerged above the crop canopy with a metal bar with high voltage electricity that electrocutes the plant. Both of these methods are still being researched and tested further, but are showing up on organic farms to help protect crop yield potential and disrupt weed cycles.
The new strategies for controlling weeds are innovative and novel, but they are not perfect and require large investments and significant amounts of time to implement. Herbicides have provided cost effective and successful solutions for decades now with new technology helping to better the use of them. However, weeds continue to evolve as well and farmers will be required to evolve with them in their management strategies, which may involve less reliance on herbicides in the future as they become less effective.
To read more about characteristics of water hemp, follow the link below:
To see the Weed Zapper, follow the link to:
