Anthracnose Fungicides

Anthracnose is a stress-related disease of annual bluegrass and creeping bentgrass, especially on putting greens. It may appear as a foliar blight, a basal stem rot, or both.

What to Look For

Irregular yellow or bronze areas progress to orange or brown thinning. Individual plants may show yellow leaves with black fruiting bodies; basal rot darkens leaf sheaths and crowns, and weakened plants pull easily from the turf.

Why It Develops

Low mowing, low nitrogen, wilt, compaction, poor drainage, traffic, and prolonged summer stress favor disease. Foliar symptoms can develop in warm humid weather, while basal rot often appears after accumulated stress.

Reduce Disease Pressure

• Maintain light, regular nitrogen rather than allowing severe deficiency.
• Raise mowing height slightly and use rolling to preserve green speed where appropriate.
• Avoid wilt and improve irrigation uniformity without keeping the root zone saturated.
• Aerify and topdress to manage compaction and organic matter.

What University Research and Extension Guidance Says

University research summarized by Kentucky shows that improved fertility, a small increase in mowing height, rolling, and light topdressing can materially reduce severity. Preventive fungicide mixtures usually outperform rescue treatments. Resistance to QoI and benzimidazole fungicides is common, so rotate FRAC groups and avoid relying on a single-site product alone.

Choosing and Using a Fungicide

Use the products below as a starting point, then match the active ingredient, FRAC group, turf species, use site, timing, rate, interval, and watering directions to the current product label. Preventive or very early applications are usually more reliable than rescue treatments after extensive injury. Rotate effective FRAC groups and combine fungicides with the cultural changes above.

Research and label note: University research may identify useful activity even when a current product label does not name this disease. That is research evidence, not a label direction. Apply a product only where the turf or application site and use pattern are permitted, and follow the complete label and applicable state requirements.

University sources: University of Kentucky: Chemical Control of Turfgrass Diseases 2024; Penn State Extension: SDHI Fungicides for Turfgrass Diseases.