Now is the time to make sure your turf is protected from Pythium diseases. While many people think of Pythium as a single problem, it is actually a complex group of diseases. Understanding the differences among these diseases is essential to their diagnosis and effective management.

You are probably familiar with the Rhizoctonia diseases - brown patch, yellow patch, brown ring patch, and large patch. Although all are caused by species of Rhizoctonia, these diseases vary widely in the conditions that trigger them, the symptoms they produce and the best approaches to their management. Similarly, Pythium blight, Pythium root rot, and Pythium root dysfunction are very different diseases. Determining which Pythium diseases have the potential to develop in your turf is a critical first step in developing an effective disease management plan.

Pythium Blight is a foliar disease, most often caused by Pythium aphanidermatum in cool-season grasses. Bluegrasses and ryegrasses are most susceptible to Pythium blight, but bentgrasses and fescues can also be affected when conditions are highly favorable. The disease is stimulated by hot and humid weather, particularly when night temperatures are consistently above 68°F. For more information about Pythium blight management, please refer to the Pythium Blight Turfgrass Disease Profile (Purdue University).

Pythium Root Rot has been one of the most frequent disease problems on putting greens over the last few years. This disease attacks the roots, crowns and other below-ground tissues and can result in rapid thinning or death of affected turf. All turf species can succumb to Pythium root rot, but it is most destructive to putting green turf. Pythium root rot can be caused by more than 20 Pythium species that collectively grow under a broad range of soil temperatures. As a result, Pythium root rot can occur virtually any time of year. The disease is triggered by wet soils from heavy rainfall, over-irrigation, or poor soil drainage. For more information about Pythium root rot, please refer to the Pythium Root Rot TurfFiles (North Carolina State University).

Pythium Root Dysfunction is a disease of creeping bentgrass putting greens that is mostly limited to transition zone climates. Newly constructed putting greens are most susceptible, with the disease becoming less severe as the greens mature over 8 to10 years. Three species of Pythium (aristosporum, arrhenomenes, volutum) have been shown to cause this disease. Infection of bentgrass roots occurs primarily in the fall and spring, causing the turf to be more prone to heat and drought stress during the summer.

Syngenta Solutions for Pythium Diseases
Syngenta offers an industry-leading portfolio of products for Pythium management:

Appear™ fungicide contains a phosphonate fungicide that provides outstanding prevention of Pythium blight and anthracnose combined with a dark green pigment that enhances turf quality and color. The proprietary liquid formulation of Appear is compatible and easy to mix with other products in the spray tank.

Subdue Maxx^® fungicide continues to be standby product for management of Pythium diseases in turfgrasses. With preventive and curative activity against a broad range of root- and foliar-infecting Pythium species, Subdue Maxx is an effective foundation for any Pythium fungicide program.

In addition to its excellent activity against brown patch, summer patch, and other summer diseases, Heritage™ fungicide offers preventative activity against Pythium blight and Pythium root rot. Heritage is also an effective option for prevention of Pythium root dysfunction in creeping bentgrass putting greens.

Briskway™ fungicide offers the Pythium control of azoxystrobin combined with a new DMI fungicide, difenoconazole, that is safe for application to putting greens even during periods of extreme stress. This powerful combination of active ingredients provides outstanding broad-spectrum control of summer diseases in putting green and fairway turfgrasses.

Daconil Action™ Fungicide contains the plant activator acibenzolar-S-methyl, which triggers natural defense responses in the turfgrass plant. Daconil Action has shown excellent activity against Pythium blight* when applied on a preventive basis.