Weeds

The 2017 Illinois corn crop currently is at various stages of development.  Applications of postemergence corn herbicides continue to be made across areas of Illinois, although the recent precipitation has delayed applications in some areas.  Even though applications may be delayed, adequate soil moisture coupled with warm temperatures will certainly promote rapid growth of emerged weeds.
Properly timing the application of the postemergence herbicide is critical toward achieving the goal of removing weed interference from the corn crop before the weeds adversely impact (i.e.,…

Following the recent and excessive precipitation, some corn replanting likely will occur when soil conditions are conducive.  We hope that replanting occurs only in small areas of a given field, but in some situations entire fields may have to be replanted.  While there are many agronomic considerations associated with replanting, some weed control/herbicide issues also should be considered.
Herbicide-resistance traits in the replanted hybrids should be taken into account.  For example, if you initially planted a glyphosate-resistant corn hybrid and have areas that need to be replanted,…

The weed science program at the University of Illinois invites all weed management practitioners to our annual weed science field tour, which will be held on Wednesday, June 28 at the Crop Sciences Research and Education Center (a.k.a. South Farm), located south of campus on Wright Street extended.  Registration will begin at 8:00 a.m. and refreshments (coffee, juice, and doughnuts) will be available.  Preregistration is not required, but please let us know in advance if you will be bringing a large group of participants so we can plan accordingly for meals.…

Decades ago it was very common for the majority of corn and soybean acres in Illinois to be treated with one or more soil-residual herbicides before crop/weed emergence.  During the 1980s, commercialization of broad-spectrum, postemergence herbicides began the shift away from widespread use of soil-residual herbicides; products such as Basagran, Classic, Accent and Pursuit contributed to the early adoption of postemergence weed control programs.  The era of total postemergence weed control reached its zenith following the widespread adoption of glyphosate-resistant crops and the concomitant use of glyphosate.  …

Are you an Illinois farmer?
 
How about an Illinois Ag chemical retailer, seed dealer, crop consultant, machinery/implement dealer, pesticide manufacture or public landowner?
 
Are you planning on attending the Commodity Classic in San Antonio in March?
 
Would you be willing to share your experiences regarding herbicide resistance management?
 
If you answered yes……..
Two weed scientists, Dr. Jeff Gonsolus (University of Minnesota) and Dr. Christy Sprague (Michigan State University), are working on behalf of the Weed Science Society of America to convene a Herbicide Resistance Management (HRM) Listening Session to be held at the Commodity Classic in San Antonio,…

Proper application stewardship of dicamba in dicamba-resistant soybean increases the likelihood of good weed control while concomitantly decreasing the potential for off-target herbicide movement.  The labels of two commercially available dicamba formulations approved for application in dicamba-resistant soybean (Engenia from BASF and XtendiMax from Monsanto) include many application guidelines and restrictions that all applicators must follow.  The Illinois Fertilizer and Chemical Association (IFCA) recently published a helpful checklist of “do’s and don’ts” for applying dicamba in dicamba-resistant soybean. …

The long-awaited label allowing dicamba use in dicamba-resistant soybean was granted November 9, 2016, by the United States Environmental Protection Agency (EPA), although only one commercial product received that label.  Many Illinois farmers anticipate this technology will provide a much-needed solution to challenges caused by weed populations resistant to herbicides from multiple site-of-action groups and other difficult-to-control species.  Without question, there are instances and scenarios in which dicamba will improve control of certain weed species, but dicamba will not bring back the “good ol’ days” of POST-only weed control programs in soybean. …

Herbicides applied in the fall often can provide improved control of many winter annual weed species compared with similar applications made in the spring.  Marestail is one example of a weed species that is often better controlled with herbicides applied in the fall compared with the spring.  An increasing frequency of marestail populations in Illinois are resistant to glyphosate, and recently we confirmed resistance to ALS-inhibiting herbicides also is present in Illinois populations.  Targeting emerged marestail with higher application rates of products such as 2,4-D in the fall almost always results in better control at planting compared with targeting overwintered and often larger plants with lower rates of 2,4-D in the spring.…