WSSA Highlights IR-4 Efforts to Provide Effective Weed Management in Watermelons

Author – Lee Van Wychen

This story originally appeared as “How a Little-Known Research Organization Keeps Watermelon on Your Picnic Menu”.

WESTMINSTER, Colorado – June 25, 2020 – Sweet, juicy watermelon can be the perfect choice for a 4th of July picnic on a warm summer day. But scientists with the Weed Science Society of America say there is one thing you might not know. It has taken a lot of work by a little-known organization to make those melons you love available.

Watermelon crops are an easy target for troublesome weeds – from Palmer amaranth to purslane and nutsedge. Plants must be widely spaced, which leaves room for weeds to become established and rob the crop of the nutrients it needs to thrive. In fact, studies show uncontrolled weeds can reduce watermelon yields by more than 80 percent.

For many years there were few herbicides approved for weed control in watermelon crops. But the Inter-Regional Research Project #4 (IR-4) is addressing the gap. Over a series of years, the organization has successfully registered 11 uses of nine herbicides to treat weeds in watermelon fields.

“Before IR-4 began its work, watermelon growers had few resources for treating weeds and other pests,” says Stanley Culpepper, Ph.D., a professor and extension agronomist at the University of Georgia. “New registrations, though, have changed the game. One great example is fomesafen, which is now available to help watermelon growers battle Palmer amaranth.”

Watermelon isn’t the only crop that benefits from IR-4. The organization is devoted to the registration of products that can safely control weeds and other pests in a wide variety of specialty crops – from avocado, asparagus, carrot and celery to cilantro, fig and cherry. Its work spans not only herbicides, but also insecticides, fungicides, and integrated solutions for the sustainable management of resistant pests.

IR-4 has been extremely successful in delivering on its mission. In fact, it is responsible for about half of all registrations approved by the U.S. Environmental Protection Agency (EPA) annually. There were 1,545 new use cases approved in 2019 alone. Each is the culmination of a multiyear effort that includes an initial needs assessment, extensive field trials and preparation of reports for the EPA’s review.

Setting priorities
IR-4 is largely funded by the USDA. Budgets have been level for a decade, which limits the organization’s capacity, experts say. That means priorities are imperative.
“We have far more demand than we are able to meet,” says Dan Kunkel, Ph.D., acting national director of IR-4. “Each year we receive hundreds of requests for support. Someone might find a solution that works, but they need help to prove it can be used safely and to get it registered by the EPA. We do that work for them.”

A large group of stakeholders helps to narrow down requests and develop annual priorities. During a typical year, the organization will take on 65 to 70 new studies involving 40 or more chemistries. About 450 field trials are underway at any time.

Stanley Culpepper, who serves as a liaison to IR-4 on behalf of growers in Georgia, says the organization is highly respected and “one of the most productive I’ve ever worked with.” His opinion is backed up by a study that shows the ripple effect IR-4 has on our food supply and our economy.

A study performed by Michigan State University found the organization produces an estimated $6.3 billion impact on annual crop production. It also fuels more than 95,000 jobs across the U.S. agricultural value chain and beyond. These jobs generate some $5.6 billion in annual labor income and contribute $9.4 billion to the country’s annual gross domestic product.

For more on the work of IR-4, visit the organization online.

About the Weed Science Society of America
The Weed Science Society of America, a nonprofit scientific society, was founded in 1956 to encourage and promote the development of knowledge concerning weeds and their impact on the environment. The Society promotes research, education and extension outreach activities related to weeds, provides science-based information to the public and policy makers, fosters awareness of weeds and their impact on managed and natural ecosystems, and promotes cooperation among weed science organizations across the nation and around the world. For more information, visit www.wssa.net.

Lee Van Wychen is the Executive Director of Science Policy for the National & Regional Weed Science Societies Lee.VanWychen@wssa.net.