Aaron Hager Email

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 within the past year we have confirmed that resistance to ALS-inhibiting herbicides also is present in Illinois populations. …

Accurate identification of weedy Amaranthus species during early vegetative stages can be difficult.  However, identification of the various species becomes much more reliable when reproductive structures are present (Figure 1).
Before harvest begins, consider taking a few minutes to scout fields; at this time of year it is much easier to differentiate between Palmer amaranth (Figure 2) and waterhemp plants (Figure 3).
Similar to waterhemp, Palmer amaranth plants are either male or female; male plants produce only pollen while female plants produce only seed. …

The weed science program at the University of Illinois would like to take the opportunity to remind everyone of the Palmer amaranth field research tour scheduled to begin at 9:00 a.m. on July 30.  The tour will feature presentations about Palmer amaranth identification, biology, and management and provide participants the opportunity to view several field experiments conducted by the University of Illinois and scientists from Bayer CropScience.  Advanced registration can be accomplished by visiting bayerrespecttherotation.com. …

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.  Adhering to these intervals is always important, but becomes particularly important with late-season herbicide applications or when soil moisture is limited.  These intervals are established to reduce the likelihood that herbicide residues will persist in sufficient quantities to adversely affect the rotational crop.  Some herbicide rotational restrictions are based solely on time,…