Update on Turfgrass Improvement via Summer Update
In the world of turfgrass maintenance, one common challenge is the appearance of summer patch disease. This disease, caused by *Magnaporthiopsis poae*, primarily affects Kentucky bluegrass, annual bluegrass, and various turf-type fine fescues. However, with the right combination of preventive cultural practices and appropriate fungicides, summer patch can be effectively managed.
## Preventive Cultural Practices
### Watering
Watering your turfgrass in the morning helps prevent prolonged moisture that fosters disease development. Avoid frequent, shallow watering, as it can exacerbate root stress.
### Fertilization Management
Avoid excessive nitrogen application, as it can promote lush growth that may increase disease susceptibility. Opt for balanced fertilizers and timing to enhance overall turf health without over-stimulating growth.
### Soil Aeration and Drainage
Improve soil drainage and consider aerating the turf to reduce soil compaction and improve root growth.
### Mowing and Thatch Management
Maintain proper mowing heights and reduce thatch to prevent moisture accumulation and promote healthy root growth.
## Fungicides for Summer Patch Management
For effective management of summer patch, delivering fungicides to the roots is essential. Use fungicides that are acropetal penetrants, meaning they move from the roots up through the plant, to effectively target the pathogen at the root level.
Consult local pest management guidelines for the most appropriate fungicides, as product efficacy can vary by region and specific conditions.
While summer patch is distinct from brown patch, similar cultural practices can help manage both diseases.
For more detailed and current recommendations, refer to the OSU Extension Bulletin L-187. Keep in mind that the optimal temperature for growth of M. poae in the laboratory is reported as 82-87°F. Additional fungicide applications may be required or recommended during periods of pathogen favorable environmental conditions.
The only sure way to identify summer patch is through analysis by a turfgrass disease specialist or clinician. It's also essential to note that at least six different patch diseases of turfgrass are recognized, including summer patch.
Overhead irrigation tends to increase disease pressure for summer patch. The roots, crowns, and stolons of heavily infected turfgrass are often severely darkened due to the presence of ectotrophic runner hyphae.
Turfgrass diseases such as summer patch, take-all patch, and spring dead spot are caused by a group of fungi known collectively as the ectotrophic root-infecting (ERI) fungi. The roots, crowns, and stolons are typically colonized during environmental periods favorable for turfgrass growth, resulting in compromised root function during periods of stress.
Symptoms of summer patch are most prevalent during prolonged hot (65-85°F), humid, or wet weather on stressed turfgrass grown in poorly drained soils. The ERI fungi produce darkly pigmented runner hyphae along the surface of and ultimately inside the vascular tissue of roots.
In newly released Kentucky bluegrass varieties, resistance to summer patch is increasingly common, offering a promising solution for future turf maintenance.
- To enhance the health and wellness of your turf, including its resistance to summer patch disease, implement preventive cultural practices such as watering in the morning, balanced fertilization, soil aeration, smart mowing, and thatch management.
- For efficient management of summer patch, choose fungicides that are acropetal penetrants, follow local pest management guidelines, and apply fungicides to target the pathogen at the root level, especially during periods of favorable environmental conditions.
