Envu Solutions – Dollar Spot
Dollar spot, caused by pathogens in the genus Clarireedia, is a widespread and very destructive turfgrass disease that occurs throughout the golf season in Canada. Dollar spot attacks most turfgrass species including annual bluegrass, bentgrasses, fescues, Kentucky bluegrass and perennial ryegrass.
The pathogen responsible for dollar spot was previously classified as Sclerotinia homoeocarpa but has now been reclassified into four separate Clarireedia species, of which, C. jacksonii is likely the predominant species in Canada.
Implementing proper cultural practices is crucial to reducing disease severity. Management tactics include:
- Maintaining adequate nitrogen fertility
- Removing dew by mowing, whipping or rolling
- Proper water management strategies, avoiding drought stress
- Aerifying to reduce compaction and thatch when disease is not active
- Removing trees or adding fans to increase air circulation
Fungicides are a key part of an integrated dollar spot management program. Since dollar spot is a foliar disease, select spray nozzles and spray volumes that provide good coverage to maximize fungicide activity. Routine fungicide applications are commonly needed when air temperatures are 21–32 ºC. The use of dollar spot prediction models, such as the Smith-Kerns model, can be a valuable resource in determining timing of first fungicide applications and the proper spray intervals. Integrating cultural and chemical control strategies provides the most effective control of this fungal disease. Preventive applications of DMI fungicides, like Mirage® Stressgard®, for fairy ring and summer patch prevention (average soil temperatures of 13 ºC at a 5–10 cm depth) also provide early dollar spot control. Mirage Stressgard can be integrated throughout the summer months as a trusted component in dollar spot control programs.
Exteris® Stressgard® is an ideal choice for dollar spot control in all weather conditions. Exteris Stressgard is especially helpful in hot weather, since it can be used without risk of negative plant-growth-regulating effects, while also controlling other summer diseases such as anthracnose and brown patch. Dollar spot resistance to DMI fungicides is also of growing concern, and Exteris Stressgard is an excellent solution for rotating fungicide classes and providing control of DMI-resistant dollar spot populations.
Dedicate® Stressgard® is also a strong option for controlling dollar spot, especially late in the season when other cool weather diseases, such as leaf spot and Microdochium patch, start to emerge. In addition to dollar spot, Dedicate Stressgard offers control of other summer diseases like anthracnose, summer patch and brown patch
No matter what kind of turf problems you’re up against, Envu has a full range of solutions to help you take control and maintain it.
For more information about dollar spot, download the solution sheet or contact your local Territory Sales Manager for dollar spot control strategies specific to your needs.
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