Zoysia Large Patch
Rhizoctonia Solani AG2-2 “LP”
• Active at thatch temperature range of 50-85 degrees
• Survives in bud nodes and inoculates leaf sheaths
• Infects nodes and stolons; roots and rhizomes not infected.
• Disease grows as mycelium
• Can move in infested soil or plant parts
• May be new patches or perennial
• Infected areas range in size from 6 inches to 20 feet in diameter.
• Uninfected Zoysiagrass will remain and grow rapidly inside the patch
• The enlargement of the lesions eventually girdles the plant and cuts off the water and nutrients supplied to the shoot.
Copper, yellow, orange band on margins of diseased areas when active. Affects crown, sheath upward
Visible around April as light brown sunken areas recovering slowly from winter dormancy with
Healthy turf around the patches greening up more rapidly. Patches may expand and Exhibit a bright orange border.
Thatch temperatures lower and the disease becomes active again. In late September to mid-October, roughly circular patches of bright orange discolored turf appear later fading to a tan color. The outer ring of the patch will usually remain bright orange in color as it continues to expand. Examine grass shoots on the outer edge of the patch for reddish-brown to black lesions on the lower leaf sheaths on the plant.
HIGHLY SUSCEPTIBLE SUSCEPTIBLE MODERATE SUSCEPTIBLE
Emerald Zeon Meyer
El Toro Zenith JaMur
BMP – Best Management Practices
• Improve drainage
• Avoid over irrigation – spring/fall
• Mow at a higher cut
• Thatch at less than ½ inch
• Avoid early fertilization until active growth
• Avoid greater than 2 lb. N per 1000 – no fertilizer after August
• Slow release N
• Higher P and K