Leafy spurge starts early; there are still control options Leafy spurge is off to a fast start this year. The yellow-green bracts are already showing up in some areas about two weeks ahead of season.
Leon Wrage, Extension weed specialist at South Dakota State University, tells how to identify the weed and provides the latest in control options.
Leafy spurge leaves are dark green and narrow. Roots may go 20 feet deep. It has milky sap throughout the plant. Seedlings can reproduce from buds after four days emergence.
South Dakota has 70,000 acres with a potential price tag to crop and livestock programs of $10 million, Wrage reported.
Areas where grass is short may give the impression that the spurge is worse this year, Wrage noted.
The yellow flower bracts signal it is time to start treating. "Do it before the seed capsules form," advised the specialist. "Fit the control to the crop and site.
In grassland, 2,4-D and Tordon can be used. Esters of 2,4-D are more effective than most amines, Wrage said.
Tordon is used for new patches. The maximum rate for spot treating has been reduced to 2 quarts per acre. It is used at lower rates with 2,4-D. Check labels for complete precautions and restrictions.
Plateau is a new product used in grassland, Wrage said. New special labeling for Plateau allows haying and grazing. Leafy spurge control with fall application has been very good and many native warm season grasses are tolerant. It's also used in new CRP. Plan to set-up the weed for fall treatment with Plateau.
Wrage said that bio-control agents, specifically insects, have been established at sites in South Dakota. They can be collected and redistributed. County weed and pest boards have details on collecting. "This gives another tool that is especially useful in sites where other options are limited, and, used hand-in-hand with other controls, keeps pressure on the weed."
Grazing with sheep and goats has been successful. Grazing weakens the plant and sets it up for insects and herbicides, Wrage said.
Tillage or herbicide before late-planted competitive crops is an option in cropland. Herbicides available for cropland are very limited. "It's important to work tillage into the system to help weaken the stand," Wrage said.
SDSU research shows that 2,4-D in crops helps prevent re-infestation from seedlings.
Contact your County Extension office for FS 525N � Noxious Weed Control.
SDSU research and Extension staff are part of a multi-state, multi-agency research project using an integrated approach to control.
The TEAM Leafy Spurge Project is focusing on the ecological area-wide management in northwest South Dakota. More data will be available as this project continues, Wrage said.