Weeds

The weed science program at the University of Illinois invites all weed management practitioners to our annual weed science field tour on Wednesday, June 24, 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.…

We had another cold and mostly dry week across the state. Average temperatures this week ranged from the low teens in northern Illinois to the high 20s in southern Illinois, between 8 and 18 degrees below average. A healthy snowpack in the southern half of the state helped push nighttime low temperatures well below 0, including lows of 7 below in Taylorville and 4 below in Jerseyville. The cold end to January pushed the month as a whole to be around 2 degrees below normal statewide.…

Weed scientists at the University of Illinois and Southern Illinois University Carbondale recently announced the confirmation of glufosinate resistance in Illinois waterhemp populations. Glufosinate is a non-selective herbicide most commonly applied postemergence in Illinois corn and soybean crops engineered with resistance to the herbicide. Use of glufosinate has increased over the past decade as the efficacy of other postemergence herbicides against waterhemp has been compromised through the evolution of resistance. This confirmation marks the first time that herbicides from all site-of-action groups previously effective for postemergence control of Illinois waterhemp have instances of resistance;…

The genus Acalypha includes approximately 450 species that are mostly of tropical and temperate origin. Approximately five species are native to Illinois, although most are not considered weeds of Illinois agronomic cropping systems. One species previously known to grow in corn and soybean fields is hophornbeam copperleaf (Acalypha ostryifolia), but due to its later emergence characteristic it rarely results in crop yield loss. Other Illinois species in this genus that usually are found in non-crop areas include the common Virginia copperleaf (Acalypha virginica) and rhomboid mercury (Acalypha rhomboidea),…