Weeds

The labels of most postemergence corn herbicides allow applications at various crop growth stages, but almost all product labels indicate a maximum growth stage beyond which broadcast applications should not be made, and a few even a state minimum growth stage before which applications should not be made.  These growth stages are usually indicated as a particular plant height or leaf stage; sometimes both of these are listed.  For product labels that indicate a specific corn height and growth state,…

The springtime color scheme provided by winter annual weed species in many no-till fields has shifted from the hearty purple of flowering henbit and purple deadnettle to the bright yellow flowers of two species.  Yellow rocket and cressleaf groundsel (a.k.a. butterweed) both produce bright yellow flowers and are common across much of the southern half of Illinois.  Although flower color is similar, the plants are distinct species.  Most of the yellow-flowered plants currently in fields is butterweed.…

We invite you to attend the 2016 University of Illinois Weed Science Field Day on Wednesday, June 29th at the University of Illinois Crop Sciences Research and Education Center, located immediately south of the main campus. Coffee and refreshments will be available under the shade trees near the Seed House beginning at 8:00 a.m.
Similar to past years, we will car pool to the fields where participants can join in a guided (but informal) tour format.…

Marestail can be one of the most challenging weeds to control prior to planting no-till soybean.  Already this season some have reported poor marestail control following applications of glyphosate plus 2,4-D.  Poor control can be caused by several factors, including large plant size and resistance to glyphosate.  If a marestail population is resistant to glyphosate, a pint of 2,4-D in the spring is generally inconsistent/ineffective when it’s the only product in a tankmix active on the resistant population.…

The following information about cover crop termination is taken from the 2016 Weed Control Guide for Ohio, Indiana and Illinois.  The information was originally written by extension weed scientists at Purdue University.
Cover crops are unique in that most are planted primarily to reduce soil erosion and otherwise enhance soil quality, and are not harvested for their seed, fruit, or forage (although some are grazed or used as forage). Instead, cover crops are terminated before planting of summer annual grain crops such as soybeans and corn.…

On February 3, Monsanto announced its commercial launch plans for soybean varieties resistant to the herbicides dicamba and glyphosate (designated Roundup Ready 2 Xtend varieties). This announcement followed China’s decision to import grain from these varieties. Many weed management practitioners hope this new technology package will provided improved control of problematic weed populations, including those with evolved resistance to glyphosate and herbicides from other site-of-action families. The weed science program at the University of Illinois has evaluated this technology for several years,…

The 2016 Weed Control Guide for Ohio, Indiana and Illinois contains 224 pages of weed management information, including weed response ratings for corn and soybean herbicides. Information and recommendations for managing weeds in small grains and forages is included, along with more specific information about and control recommendations for several problem weed species. A pdf of the 2016 Weed Control Guide is available to download, and a printed version of the guide can be ordered at: http://estore.osu-extension.org/2016-Ohio-Indiana-and-Illinois-Weed-Control-Guide-P433.aspx
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Here is the final installment of considerations for weed management in 2016.
 
Steps for Successful Weed Management in Glufosinate-Resistant (Liberty Link) Soybean
 
Step 1:
Plant Liberty Link soybean seed into a weed-free seedbed
Achieve a weed-free seedbed through the use of:
                          1) Preplant tillage
                          2) Effective burndown herbicide(s)
                          3) A combination of tillage and burndown herbicides
 
Step 2:
Select and apply within 14 days of planting a soil-residual herbicide that targets your most problematic weed species.…