Bur Buttercup (Ranunculus testiculatus)

All plant descriptions and control methods courtesy University of Nevada Cooperative Extension

Bur buttercup is a low-growing annual that is native to southeastern Europe. It has become a common weed in small grain crops, pastures, rangelands, waste areas, and along roadsides in most western states, including Nevada. Bur buttercup is especially competitive in dryland, small grain crops and is highly toxic to sheep and cattle. The sap in the plants can cause skin blistering on susceptible people. The prickly seeds stick to shoes, clothes, and animal fur, easily spreading the weed. This weed can cause significant agricultural losses and out compete native species. Millions of acres of sagebrushgrass rangelands are currently infested. In rangelands, growth and development is very dependent upon soil moisture and weather. Infestation levels may fluctuate year to year.

Distinguishing features:

• This short plant only grows 2 to 5 inches tall.
• The basally attached, grayish green leaves are 1 to 4 inches long and resemble a crow’s foot.
• They have blades that are divided into finger-like segments.
• The small, yellow flowers have 5 petals and develop early in spring.
• The flowers develop into stiff, spiny, brown burrs about 1/2 to 3/4 inch long that contain seeds..

CONTROL MEASURES

Most Effective Strategy:
Maintaining competitive vegetation is the most efficient method of keeping bur buttercup under control. Using an herbicide may be necessary if competitive vegetation cannot keep the weed from proliferating.

Mechanical Control:
Repeated tillage and cultivation throughout the year before flowering occurs is effective. Mowing is ineffective.

Cultural Control:
Do not graze this weed. It is poisonous to livestock. Planting grasses may help control the density of this weed; however, it may still flourish in the interspaces among bunchgrasses.

Biological Control:
There are currently no biological control agents for bur buttercup.

Read and follow the label. It is the law!

Chemical Control:

Chlorsulfuron (Telar®)
Rate: Use 0.66 to 0.75 ounces a.i. per acre of chlorsulfuron (1/2 to 1 ounce of Telar® per acre).
Time: Apply during preemergence or early postemergence when plants are actively germinating or growing.
Remarks: When making postemergence applications, use a nonionic surfactant to increase the herbicide’s effectiveness. In alkaline soils, above pH 7.5, reestablishment of competitive vegetation may be difficult due to residual herbicidal action on germinating seedlings.
Caution: Apply only to noncrop sites. Chlorsulfuron is a selective broadleaf herbicide that also affects many grasses. Follow the label directions, especially as they apply to herbicide persistence in the soil and effect on any competitive vegetation. Do not contaminate water.

Chemical Control For Croplands:

Harmony Extra® is registered for control of bur buttercup in small grains such as wheat or barley. For alfalfa crops, Balan®, Gramoxone®, Lexone®, Sencor®, and Velpar® are recommended. Contact an office of the University of Nevada Cooperative Extension or your chemical dealer for specific recommendations.

If you arrived at this page from another link and would like to know more about the Spring Creek Region Cooperative Weed Management Area please click here:  SCR CWMA