Evaluation of Electrocution for Weed Control and Tall Fescue Seedhead Reduction in Missouri Pastures

Abstract Despite its efficacy, little research has been conducted to evaluate the potential for electrocution to control common weeds in pastures. Electrocution could also potentially be utilized as a management tool to minimize the production of tall fescue seedheads to prevent fescue toxicosis in cattle. Separate experiments were conducted in Missouri in 2023 and 2024 to: 1) evaluate the effectiveness of electrocution on tall fescue seedhead management, and 2) evaluate forage injury and weed control following electrocution in comparison to common pre-packaged pasture herbicide combinations in mixed tall fescue and legume pastures. Sequential electrocution passes spaced 2 wk apart was the only electrocution treatment that resulted in reduced tall fescue seedhead density more than the nontreated control. However, metsulfuron-containing herbicide treatments reduced tall fescue seedhead density by 70 to 77%. In the weed control experiments, electrocution was compared to herbicide application in six mixed tall fescue and legume pastures and two johnsongrass-infested pastures in Missouri in 2023 and 2024. Most pre-packaged herbicide combinations tested eliminated white clover whereas electrocution and weed wiping had minimal effects on this species. The best electrocution treatments resulted in control of common ragweed, ironweed, common cocklebur, johnsongrass, and tall goldenrod and were comparable to that observed with the best herbicide treatments. Blackberry, sericea lespedeza and coralberry were most effectively controlled by weed wiping with glyphosate compared to all other treatments. Two passes of glyphosate with the weed wiper at 5 km/h spaced 2 wk apart providing the highest and most consistent control of johnsongrass. Results from these experiments indicate that electrocution can be used as a viable alternative to broadcast herbicide treatment for the control of several weeds that commonly occur in mixed tall fescue and legume pastures without significantly impacting forage yield or causing legume injury.