By Travis Roberson, Ph.D., technical services field manager for Syngenta Digital Platforms

Anthracnose | Fairy Ring | Summer Patch 

The 2025 winter season was challenging, with relatively cold temperatures and extreme weather events occurring in many regions of the country. As we transition from late winter to early spring, new seasonal challenges are on the horizon for many areas beginning to plan for spring disease management. Several key spring diseases may be on your mind, such as anthracnose, fairy ring and summer patch.

Maximizing control of these diseases begins by equipping yourself with the most accurate knowledge of proper chemistry and optimal application times. GreenCast^® Connect, a new mobile app from Syngenta, can help you optimize your application timing by pairing site-specific weather data with predictive modelling to alert you when action is needed. The weather data driving the alerts captures information based on the location the user establishes and geolocates to within 3.25 square miles for a high-level of precision.

Anthracnose

Conditions favoring anthracnose development range from cool and wet to hot and dry. The disease is more prevalent when turfgrass is stressed because of cultural practices, drought, soil compaction, poor water drainage and/or low fertility inputs. View the fungicide efficacy chart to see leading solutions for anthracose control .When conditions are favorable for disease development, consider applying Ascernity^® fungicide (1 fl. oz./1,000 ft.²), Daconil^® Action^™ fungicide (3.5 fl. oz./1,000 ft.²) and Velista^® fungicide (0.5 oz./1,000 ft.²). To see all leading solutions for anthracnose control, view the fungicide efficacy chart here and learn more about tips for anthracnose control on Poa annua greens here. 

GreenCast Connect links data to disease development, helping users confidently choose the best timing for product applications. Visual alerts are displayed as a concise view of current conditions on the dashboard (Figure 1A) and a more detailed view with a seven-day historical, current and seven-day forecast of the disease outlook (Figure 1B).

Fairy ring 

Fairy ring, a common turfgrass disease, has three types, with Type 1 being the most difficult to manage. Type 1 causes hydrophobic soils that repel water in actively growing areas, leading to drought stress later in the season. Monitoring for preventive applications begins in the spring when soil temperatures remain >55°F, and treatment is recommended when soil temperatures are sustained >60°F. Rotating Briskway^® (0.7 fl. oz./1,000 ft.²), Velista (0.7 fl. oz./1,000 ft.²) and Posterity^® XT  fungicides (3 fl. oz./1,000 ft.²) is recommended, depending on whether you manage ultradwarf bermudagrass or creeping bentgrass putting greens. 

Summer patch 

Summer patch affects several cool-season grass species, especially Kentucky bluegrass, as well as mixed stands of annual bluegrass and creeping bentgrass putting greens. On putting greens with mixed cool-season turf the disease becomes difficult to control once symptoms appear. Symptoms of infection include thinned or wilted turfgrass with white, bleached leaves coalescing into larger yellow patches of affected areas from 3-18 in. in diameter. These patches do not become apparent until stressed conditions of >85°F occur, but the root infection by the fungus occurs much earlier in the season when soil temperatures begin to exceed 65°F at a 2-in. soil depth for three consecutive days. This fungal colonization in the roots compromises and weakens the desired turfgrass species. 

Timing applications for disease management is crucial. Consider fungicides like Headway^® (1.5-3 fl. oz./1,000 ft.²),  Posterity XT (1.5-3 fl. oz./1,000 ft.²) and Velista (0.5-0.7 oz./1,000 ft.²). Visit the online disease ID guide and fungicide efficacy chart on GreenCastOnline.com for additional control options. 

For a more compact overview of pests related to your organization, GreenCast Connect features a customized Pest Risk Monitor overview (Figure 4) within the dashboard. This allows users to get a snapshot of their current conditions and a three-day forecast of what actions to expect. 

For even more precision, users with Spiio^™ soil sensors can customize thresholds related to site-specific, in-ground soil data and receive alerts driven by desired soil moisture, temperature or salinity thresholds (Figure 5). Capturing this level of insight that is backed by data from your property allows you to maximize treatment efficacy for these diseases and many others featured in the GreenCast Connect app. 

Learn more about GreenCast Connect or download the app at GreenCastConnect.com. 

All photos are either the property of Syngenta or are used with permission. 

© 2025 Syngenta. Important: Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties and/or may have state-specific use requirements. Please check with your local extension service to ensure registration and proper use. Action^™, Ascernity^®, Briskway^®, Daconil^®, GreenCast^®, Headway^®, Posterity^®, Velista^® and the Syngenta logo are trademarks of a Syngenta Group Company. Spiio^™ is a trademark of Spiio, Inc. All other trademarks are the property of their respective third-party owners.