War Against Weeds

In the last episode of season 11, Sarah and Alyssa sit down with Dr. James Leary to explore the innovative world of herbicide ballistic technology. James shares how his work in Hawaii led to the development of herbicide-filled projectiles designed to target invasive plants in hard-to-reach terrain. The conversation dives into the science, logistics, and surprising practicality of "shooting weeds," and how creative thinking can transform invasive species management and conservation efforts. Here are some resources our guest shared! https://www.youtube.com/watch?v=988i6SQKSzY https://www.youtube.com/watch?v=tWYR6C3T3NQ Transcript: PDF: https://app.box.com/s/a2cicz0jpo74m02otm8bjhkmcngjjns7 DOC: https://app.box.com/s/ekzn3mq1jwi0hlq449qz5a49ip7ilmes

This week Joe Ikley and Sarah Ganske are joined by Dr. Tom Mueller (University of Tennessee) to discuss sprayer hose cleanout and herbicide residue risks. The conversation focuses on how hose materials, aging, and system design affect herbicide retention, with research insights comparing dicamba and 2,4-D cleanout challenges. They also share practical recommendations for applicators, including agitation practices, downtime risks, and when hose replacement may be necessary to avoid crop injury. Link: https://utcrops.com/ Transcripts: PDF: https://app.box.com/s/4esrl1zv0dd0za3uojxah0jpwvqdy90i DOC: https://app.box.com/s/frnfuvcvn5t7h6kg11v4cch4jmeigsny

In this episode of War Against Weeds, hosts Alyssa Essman and Joe Ikley sit down with Melissa Widhalm, Associate Director and Regional Climatologist at the Midwestern Regional Climate Center (MRCC). Melissa introduces WEST — the Weed Emergence Scouting Tool — an experimental, temperature‑based system designed to predict first and peak emergence of key weeds like giant ragweed and waterhemp across the Midwest.

Season 11 opens with Dr. Brad Hanson of UC Davis, who joins Joe and Alyssa to unravel the resurgence of broomrape, a challenging parasitic weed threatening California's tomato processing industry. Brad explains how broomrape's underground lifecycle, tiny long-lived seeds, and strict reliance on host plants make it difficult to detect and manage. The episode covers the difference between broomrape species appearing in North America, why processing tomatoes are especially vulnerable, and how broomrape spreads through equipment and soil movement. Here are some sources Dr. Hanson shared for the listeners: UC broomrape page (in progress) https://broomrape.sf.ucdavis.edu/ California Tomato Research Institute's broomrape resource page (mostly UC extension info) https://tomatonet.org/grower-resources/broomrape-resources/ California Department of Food and Agriculture broomrape program page https://www.cdfa.ca.gov/plant/ipc/broomrape/ This is a video article that the UCD college of ag put together a couple years ago https://caes.ucdavis.edu/news/parasitic-weeds-threaten-tomato-plants-california-farms

Joe Ikley and Sarah Lancaster discuss the North Dakota Agricultural Weather Network (NDAWN) and the Kansas Mesonet with directors Daryl Ritchison and Chip Redmond, respectively. NDAWN, with over 250 stations, provides high-resolution weather data, including soil moisture and temperature measurements. Kansas Mesonet, with 94 stations, focuses on real-time data for agricultural and emergency management purposes. Both networks emphasize the importance of accurate weather data for herbicide application, particularly wind speed, inversions, and delta T measurements. The conversation highlights the critical role of Mesonets in agriculture and emergency response.

Dr. Jason Norsworthy from the University of Arkansas sits down with Alyssa and Sarah to discuss the United Soybean Board's weed management project. This project involves screening for resistance to our most used herbicides in our most problematic pigweed species.

Alyssa Essman and Sarah Lancaster sit down with Dr. Aaron Hager (University of Illinois) and Ryan Henry (UPL) to discuss Group 5 herbicides. They cover the historical use and mechanisms of these herbicides, as well as degradation, metribuzin rates, and new herbicides to the market. Paper mentioned in the episode: Optimizing metribuzin rates for herbicide-resistant Amaranthus weed control in soybean link: https://www.cambridge.org/core/journals/weed-technology/article/optimizing-metribuzin-rates-for-herbicideresistant-amaranthus-weed-control-in-soybean/ECF728739388A3DB5BA2290B1105A385

Sarah & Joe sit down with Dr. Eric Patterson from Michigan State University to chat about the The HERMON (Herbicide Resistance Monitoring Network) project. This project aims to create a network of researchers to develop and share new resistance tests and management strategies. The project includes 10 states and focuses on key herbicides like glyphosate, PPO inhibitors, and dicamba. Link mentioned in the episode: https://www.seedworld.com/us/2025/06/19/a-unified-front-on-weed-resistance/