Leafy spurge

The South Dakota Department of Agriculture reports that leafy spurge infests 309,420 acres of land in the state.

The South Dakota Department of Agriculture reports that leafy spurge infests 309,420 acres of land in the state.

The South Dakota Department of Agriculture reports that leafy spurge infests 309,420 acres of land in the state. - See more at: http://igrow.org/agronomy/corn/leafy-spurge-is-rapidly-developing/#sthash.mh6YTvFB.dpuf

One of the many challenges producers face each year is weed control. Leafy spurge, in particular, can be difficult to manage.

“Weed control is highly dependent on weather,” said Paul O. Johnson, SDSU Extension Weed Science Coordinator. “You have to react to it depending on temperature and weather conditions.”

SDSU Extension offers the following recommendations to help manage leafy spurge and other weeds in South Dakota fields:

Look for yellow flowers – Yellow flowers indicate that it is time to start spraying. For best results, spray within one month of when yellow flowers are spotted. Prompt spraying will help to ensure there is no viable seed in the plant.

Look for thistle – If Canadian thistle is spotted among leafy spurge, waiting an additional couple of weeks may help to manage both weeds. However, waiting too long may allow the root reserves to build back up in the plant and cause weeds to come back stronger than before and prevent weed control progress.

Use flea beetles – In some areas, the use of flea beetles has proven to provide adequate weed control. The beetles may take three to five years to gain complete control, but once they are established, they can help manage areas where spraying is difficult.

For more information and recommendations on controlling leafy spurge, Canadian thistle and managing other common noxious weeds, view the 2020 Noxious Weed Control Guide at https://extension.sdstate.edu/weed-control-noxious-weeds or contact SDSU Extension Weed Science Coordinator Paul O. Johnson at paulo.johnson@sdstate.edu or 605-688-4591.