War Against Weeds

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.

In this episode Alyssa Essman and Sarah Lancaster sit down with Washington State University toxicologist Dr. Allan Felsot for a crash course in Toxicology 101. Dr. Felsot breaks down how the EPA evaluates pesticide safety, explains the difference between hazard and risk, and clarifies common misconceptions about chemical exposure, tolerance, and persistence. The conversation also touches on glyphosate, PFAS-related concerns, and why effective science communication—and early education—matter for helping the public understand pesticide technology.

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

On our last episode of season 10, all three hosts have a discussion on the future of weed science with Dr. Larry Steckel (University of Tennessee) and Dr. Aaron Hager (University of Illinois). They reflect on the evolution of weed management, including the increase of specific weed species, and the challenges of herbicide resistance. Both emphasize the need for integrated approaches, including cover crops, precision technology, and cultural practices.

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.