Byhalia Grass in Horse Pasture: Toxicity Risks and Control

Identifying and Managing Byhalia Grass (Paspalum notatum)

That sticky-seeded grass taking over your North Carolina horse pasture is likely bahiagrass (often called "byhalia" locally). The seed heads can harbor ergot fungus (Claviceps paspali), posing genuine risks to pregnant mares and cattle.

Toxicity Facts

• Ergot-infected seed heads cause abortion in pregnant mares
• Cattle show neurological symptoms from ingestion
• Risk peaks in late summer/fall when seed heads mature
• Not all bahiagrass is infected—depends on weather conditions

Immediate Management Strategies

Mowing Protocol

Mow before seed heads form (every 3-4 weeks during growing season). This prevents ergot development and reduces sticky seed nuisance.

Pasture Rotation

Remove pregnant mares from bahiagrass-dominant pastures during seed head season (August-October).

Herbicide Options

• Metsulfuron-methyl (Cimarron®, others): Selective for bahiagrass in bermudagrass
• Glyphosate spot treatment: For severe infestations, then reseed
• Imazapic (Plateau®): Pre/post-emergent control

Always follow grazing restrictions on labels.

Long-Term Pasture Renovation

1. Soil test and amend (bahiagrass thrives in low fertility)
2. Establish competitive forage grasses (bermudagrass, novel-endophyte fescue)
3. Maintain proper pH (6.0-6.5) and fertility
4. Rotationally graze to prevent overgrazing

Expert Resources

NC State Extension's "Forage Management" publications and your local livestock agent can design a pasture renovation plan specific to your acreage and herd.

The daily cleaning hassle is annoying, but the reproductive risk to broodmares makes this a management priority, not just a nuisance.