2019 WiscWeeds Research Coalition Combine Weed Seed Collection Project

by Rodrigo Werle (UW-Madison Extension Cropping Systems Weed Scientist), Nick Arneson (UW-Madison Weed Science Outreach Specialist) and Dan Smith (UW NPM Southwest Wisconsin Regional Specialist)

Though native to Wisconsin, waterhemp has spread like wildfire and become a major problem in agricultural fields across the state in the past few years. In the fall of 2018, stakeholders submitted seed samples from 88 populations from across the state. UW-Madison Agronomy Grad Student Felipe Faleco has screened them for resistance to glyphosate and imazethapyr (Pursuit) and found that more than 90% of the waterhemp populations screened are resistant to both herbicides applied at their respective label rates (Roundup PowerMax at 22 fl oz/acre and Pursuit at 4 fl oz/acre).

Combines are very effective weed dispersal agents, moving weed seeds within and across fields. Our objectives with this project are to evaluate: i) how often combines are contaminated with weed seeds, ii) which weed species are common combine contaminants, and iii) the main places within combines weed seeds hide. To participate in the project, please download, print and fill out the collection protocol (click here to download the PDF file), and watch the brief instruction Vimeo video:

Samples must be collected after harvesting a crop field and before combines are winterized. Next spring and summer (2020), samples will be mixed with soil, placed in flats and watered daily in the greenhouse. The number of weeds and species will be recorded and flats will be sprayed with glyphosate when plants are established to evaluate the incidence of glyphosate-resistant weeds. A summary of our research findings will be made available in the Fall of 2020. We thank you in advance for your interest and participation in this collaborative project.

WiscWeeds Research Coalition - About:

Given the widespread occurrence of herbicide-resistant weeds across Wisconsin Cropping Systems, the shortage of novel herbicide sites of action, and the socioeconomic and environmental challenges herbicide-resistant weeds bring to farming operations and communities, it’s time for our industry to come together and work towards a similar goal: to promote and hopefully achieve effective and sustainable weed control in crop production systems.

The objective of the WiscWeeds Research Coalition is to bring together Researchers, Educators, Policy Makers, Industry, Consultants, Service Providers, and Growers to work towards preventing the spread, reducing the selection for, and to increase the adoption of integrated management strategies to combat herbicide-resistant weed species. Through the WiscWeeds Research Coalition we expect to develop a strong relationship amongst key stakeholders allowing for effective exchange of materials, practical knowledge and research-based recommendations.

“Alone we can do so little; together we can do so much” Helen Keller

Rodrigo Werle, Nick Arneson and Dan Smith