Biocontrol of Leafy Spurge - Central Region

(Sponsored by Manitoba Agriculture and Food)

(Funded by Covering New Ground)

 

Introduction

The objective of this project is to use sheep as a method of controlling leafy spurge, a noxious weed that poses a threat to cattle producers. Cattle will not eat these weeds, so the weeds quickly spread and choke out the more suitable forage. Sheep are used as a herbicide-free alternative for this weed problem. This project started in 2000 on a farm south of Morden, Manitoba.

Pasture set-up

A one-acre paddock was fenced off and five sheep (dry ewes) were put on the pasture for the summer of 2000. Adjacent to this paddock, cattle were allowed to graze as they always had. A three-wire electric fence was used to keep the sheep in and the predators out. The sheep grazed from July 27 to September 7.

Leafy spurge measurements

A volume index (plant height X ground cover) of the leafy spurge was taken before the sheep entered and after they had grazed the paddock. On July 27, the volume index in the sheep paddock and  the cattle paddock was 3.6. On September 7, the volume index was 0.6 inside the sheep paddock and 2.0 outside where the cattle had been grazing. The sheep reduced the volume of the leafy spurge by 6 times, while tramping by the cattle only reduced the volume by 1.75 times.

Sheep preferred leafy spurge

The leafy spurge found in the sheep paddock had all the leaves stripped and the regrowth was eaten down. The sheep actually preferred the leafy spurge to the grasses and other vegetation in the paddocks.

This year's study

In 2001, the paddock is divided into two sections (one-half acre each). Eight sheep (five ewes and three lambs) were put into the site on May 29. The volume index on the pasture was 1.5 outside each paddock, 2.0 on the east paddock and 4.4 on the west paddock. The sheep are rotated from side to side as needed.

For further information:

This study is ongoing and more information about this project can be obtained from Brian Nedohin, Agricultural Representative in Morden, Manitoba. He can be reached at (204) 822-5461.