Written by
Alfredo Martinez. UGA Plant Pathology Department-Griffin campus
Rhizoctonia Large patch of turfgrass is most common in the fall and in the spring as warm season grasses are entering or leaving dormancy. Large patch is caused by the soilborne fungus Rhizoctonia solani (AG 2-2LP). It can affect all warm-season turfgrass species. The disease produces irregularly-shaped weak or dead patches that are from 2 feet to up to 10 feet in diameter. Inside the patch, you can easily see brown sunken areas. On the edge of the patch, a bright yellow to orange halo is frequently associated with recently affected leaves and crowns. The fungus attacks the leaf sheaths near the thatch layer of the turfgrass.
Large patch disease is favored by:
- Thick thatch.
- Excess soil moisture and poor drainage.
- Too much shade, which stresses turfgrass and increases moisture on turfgrass leaves and soil.
- Early spring and late fall fertilization.
If large patch was diagnosed earlier in the season, fall is the time to prevent and manage it. Cultural practices are important in control of the disease. Without improving cultural practices, you may not achieve long term control. READ MORE
