Weeds

Utilization of soil-applied herbicides in corn and soybean production systems continues to be a common method to achieve weed control. Early preplant, preplant incorporated, and preemergence surface are the most common types of herbicide applications to soil. Regardless of when the herbicide was applied to the soil, the effectiveness of soil-applied herbicides is governed by several factors.
The primary factor which governs the efficacy of soil-applied herbicides is having the herbicide available for uptake by the germinating weed seedling.…

The weed science program at the University of Illinois invites all weed management practitioners to our annual weed science field tour on Wednesday, June 25, at the Department of Crop Sciences field research location known as the Clem Farm, located at 1114 County Road 1200 East, Champaign. Registration begins at 8:00 a.m. and the tour will start at 9:00 a.m. 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.…

This is reminder that the only two labeled formulations of 2,4-D that can be applied postemergence in 2,4-D-resistant soybean varieties are Enlist One and Enlist Duo. No other salt formulations and no ester formulations can be applied postemergence to these varieties. Ester formulations are more volatile than salt formulations and volatility can increase with the warmer air and soil temperatures that typically occur when postemergence applications are made. A bill to ban the sale and application of 2,4-D ester formulations has been introduced in the Illinois legislature multiple times;…

The weed science program at the University of Illinois invites all weed management practitioners to our annual weed science field tour on Wednesday, June 26 at the Department of Crop Sciences field research location known as the Clem Farm, located at 1114 County Road 1200 East, Champaign. Registration begins at 8:00 a.m. and the tour will start at 9:00 a.m. 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.…

The weed science program at the University of Illinois invites all weed management practitioners to our annual weed science field tour on Wednesday, June 26 at the Department of Crop Sciences field research location known as the Clem Farm, located at 1114 County Road 1200 East, Champaign. Registration begins at 8:00 a.m. and the tour will start at 9:00 a.m. 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.…

On February 6, 2024, a federal court in Arizona vacated the labels of three dicamba-containing products used for in-crop broadleaf weed control in dicamba-resistant soybean varieties. The court ruled that the United States Environmental Protection Agency (EPA) violated the Federal Fungicide, Insecticide, and Rodenticide Act (FIFRA) when the agency relabeled these products following the previous label vacatur issued by the Court of Appeals for the Ninth Circuit in 2020. It is important to clarify this recent court ruling and label vacatur affects only three products: XtendiMax (Bayer CropScience),…

The continual evolution of weed species and populations resistant to herbicides from one or more site-of-action groups represents one of the most daunting challenges facing Illinois soybean producers. Waterhemp has evolved resistance to herbicides from more site-of-action groups than any other Illinois weed species, including resistance to Group 15 herbicides (products such as Dual II Magnum, Zidua, Warrant, Outlook, etc.). Soil-residual herbicides are components of an integrated weed management program that provide several benefits, including reducing the intensity of selection for resistance to foliar-applied herbicides.…

 
Nearly all herbicide labels (soil-applied or postemergence) have rotational crop intervals that specify the amount of time that must elapse between herbicide application and planting a rotational crop. This becomes particularly important with late-season herbicide applications, and when soil moisture is limited. Additionally, the labels of almost all postemergence soybean herbicides indicate a preharvest interval or a soybean developmental stage beyond which applications cannot be made. Labels of some products may indicate both a developmental stage (before soybean bloom,…

The weed science program at the University of Illinois invites all weed management practitioners to our annual weed science field tour on Wednesday, June 28 at the Department of Crop Sciences field research location known as the Clem Farm, located at 1114 County Road 1200 East, Champaign. Registration begins at 7:30 a.m. and the tour will start at 9:00 a.m. 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.…