Updates to Controlling/Managing HR Weeds

Another growing season is upon us. And among the many constants producers will encounter during this new season is the continuing battle against weeds in soybeans, especially those that have developed resistance to commonly-used herbicides.

In previous blogs and in the several White Papers on this website that deal with the Herbicide-Resistant (HR) weeds subject, producers have been kept apprised of the many tools that have been and are being developed to combat this plague to soybean growers. Following are links to recent articles/items that have the potential to increase the arsenal of weapons that producers can use in this battle.

In an article titled Cover crops can swamp fallow weeds (Dec. 23, 2020), author Cindy Benjamin summarizes results from Australian research conducted by Dr. Annie Ruttledge, a scientist with the Queensland Dept. Of Agriculture and Fisheries. As indicated by the article’s title, this research is directed toward using competition from cover crops to suppress weeds during the fallow periods that commonly occur in row-crop agriculture. Using cover crops to suppress weeds is part of the WeedSmart Big 6 program (see following paragraph). Use of cover crops to suppress weeds in Midsouth production systems is covered in detail in a Cover Crops White Paper on this website.

Australia’s agricultural sector has united to establish WeedSmart, which is an industry-led effort to enhance farm practices that promote the long-term sustainability of herbicide use. This organization delivers science-based weed control solutions to growers and advisors that should enhance long-term profitability in Australian agriculture. Their purpose is to encourage actions that will minimize the effect of weeds as a factor in crop production systems through the implementation of their Big 6 program. One of the six components of this program is Harvest Weed Seed Control (HWSC), which is covered in detail in an HWSC White Paper on this website.

On the subject of HWSC, a FarmProgress article titled “Weed Seed Destroyer could help address pigweed issues“ (Mar. 25, 2021) by Forrest Laws highlights a potential new tool for killing weed seeds as they exit the combine during soybean harvest. Global Neighbor, Inc. (GNI) is working to develop the Weed Seed Destroyer, an apparatus that will attach to the rear of the combine and apply a blend of high-intensity light for a short duration to kill weed seeds in the chaff as it exits the combine. GNI’s patented Directed Energy (DE) technology will render the expelled weed seeds nonviable or sterile using dual-wavelength, unnatural illumination sources. This DE technology was developed with support from the US Air Force’s SBIR/STTR Program. GNI’s agriculture products are being developed with support from USDA’s SBIR Program.

It is likely there is no one existing or future tool that will mitigate the problem farmers have with HR weeds. However, it is certain that some of the effective new and forthcoming non-chemical weed control tools will need to be employed along with the dwindling arsenal of efficacious herbicides to control the increasing number of HR weed species that have evolved/are evolving, and to sustain the use of current herbicides.

Composed by Larry G. Heatherly, Mar. 2021, larryheatherly@bellsouth.net