Finish the Race Well: Late Fall Dollar Spot
Dollar spot can remain active on golf course turf well into late fall—when cool, moist conditions persist. Because turf growth slows, recovery is limited, and scars may persist into spring. Late-season outbreaks can be especially severe due to high humidity, long leaf wetness, and reduced fungicide protection.
Key Recommendations:
- Monitor disease pressure using predictive tools such as the Smith-Kerns model.
- Maintain balanced fertility; avoid both nitrogen deficiency and excess to reduce stress and disease susceptibility.
- Limit leaf wetness by removing dew, rolling, improving airflow, and enhancing drainage.
- Promote preventive cultural practices (e.g., aeration, verticutting, topdressing) and communicate their importance to members and management.
- Maintain season-long fungicide protection - do not stop applications too early; a final spray is advised if disease pressure remains high.
- Rotate fungicide modes of action and incorporate multi-site products to minimize resistance development.
- Apply fungicides preventively or protectively before outbreaks to reduce disease severity and, in some cases, prevent outbreaks altogether.
- Avoid late-season DMI applications if resistance is present (which is likely across most fairways due to widespread prevalence).
- Use caution with SDHI, benzimidazole, and dicarboximide fungicides - if resistance is detected, they should not be used late season; if no resistance is detected, they remain viable options.
- Rely on contact, multi-site fungicides such as chlorothalonil or fluazinam for late-season applications. Their activity is topical with shorter residual control, so tank-mixing with a QoI fungicide (e.g., fluoxastrobin, mandestrobin, or pyraclostrobin) is strongly recommended for extended protection.
Bottom line: Don’t let your guard down - late fall dollar spot can still cause major damage and carry over into spring.
Submitted by: Dr. Geunhwa Jung