By Blake Jackson
The Wisconsin Extension Weed Management Team hosted a day-long workshop on September 12th, 2024, at the University of Wisconsin-Madison Arlington Agricultural Research Station.
Around 90 participants from Southern Wisconsin and Northern Illinois attended the event, which featured presentations, demonstrations, and a weed knowledge contest.
Focus on Application Technology
Dr. Tommy Butts, a weed scientist from Purdue University, kicked off the event by discussing application technology and its impact on drift and weed control. He highlighted the importance of factors like spray volume, pressure, droplet size, and nozzle selection.
Participants learned that nozzle type significantly affects droplet size, thus influencing drift potential. For instance, Dr. Butts presented data showing a shift from 25.8% drift-prone fines to just 2.8% when switching nozzles.
Dr. Butts also compared drone and ground rig applications. His research showed similar weed control with Gramoxone using either method, but the drone application resulted in uneven spray distribution across the swath.
Herbicide Use in Alfalfa and Research Updates
Dr. Mark Renz addressed herbicide programs and application timing in alfalfa. Early-season weed control can improve quality but might decrease yield due to reduced weed biomass.
Herbicide selection depends on the predominant weed species and their presence in the field. Roundup-Ready alfalfa is ineffective against resistant waterhemp, requiring residual herbicides like Warrant for post-emergence control.
Dr. Rodrigo Werle and the WiscWeeds Team presented ongoing research projects and recommendations. They emphasized the importance of even spray coverage with new targeted technologies like See & Spray. Their experiment demonstrated significantly better weed control with multiple nozzle activation compared to a single nozzle.
The team also discussed research on herbicide tank mixes. Enlist One and Liberty offered better waterhemp control when combined compared to using them alone.
Similarly, atrazine and mesotrione provided a synergistic effect for corn, but with restrictions on atrazine, alternative options like bromoxynil combined with mesotrione showed promising results for waterhemp and giant ragweed control.
Cover Crops and Combine Cleaning
The team highlighted research on using cereal rye cover crops to suppress weeds in soybeans. They found that a thick rye stand with around 4,500 pounds of biomass is needed for effective suppression.
Additionally, Dan Smith from the Extension Program emphasized the importance of proper combine cleaning to prevent weed seed dispersal.
The afternoon featured a second presentation by Dr. Butts on herbicide application chemistry. He addressed water quality, tank mixing compatibility, and herbicide antagonism.
The event concluded with demonstrations by sponsors and partners showcasing nozzle technology, organic weed management tools, and new precision application technology using AI-powered cameras for targeted spraying.
Photo Credit: gettyimages-zoomtravels
Categories: Wisconsin, Education