DESCRIPTION OF THE DISEASE
Leaf blotch appears as tiny purplish to reddish spots that occur on leaf blades and leaf sheaths. Seedlings are very susceptible, but older plants rapidly become resistant. Affected seedlings wither, die, and turn brown. The roots and crowns of infected plants may develop small lesions and rot. The disease occurs in irregular patches that range in size from 2 inches to 3 feet across.

SUSCEPTIBLE TURFGRASSES
Leaf blotch is a disease of bermudagrass. The pathogen survives in infected bermudagrass plants and debris.

CONDITIONS FAVORING DISEASE
Leaf blotch damages young bermudagrass seedlings or adult plants that are weakened by factors such as excess thatch, nitrogen deficiency, and other unfavorable growing conditions. The disease attacks during cool, wet weather, with symptoms usually seen from late autumn to spring.

MANAGEMENT
Follow good management practices; fungicides are usually not necessary except in young turfgrass.

Cultural Control
Remove thatch at regular intervals and apply adequate nitrogen to help prevent the development of this disease. Manage leaf wetness by irrigating pre-dawn to early morning.

Treatment Decisions
Fungicides are primarily used in young turfgrass; established, healthy turfgrass is not usually damaged by this disease.

Common name Chemical class

Many of these products are available for use by licensed applicators only and cannot be used by home gardeners.

A. AZOXYSTROBIN QoI (strobilurins)

B. CAPTAN Pthalamide (multi-site)

C. CHLOROTHALONIL Chlorophenyl (multi-site)

D. FLUDIOXONIL Phenylpyrrole

E. IPRODIONE Dicarboximide

F. MANCOZEB EDBC (multi-site)

G. MYCLOBUTANIL DMI

H. PROPICONAZOLE DMI

I. THIOPHANATE-METHYL Benzimidazole

J. TRIFLOXYSTROBIN QoI (strobilurins)

K. VINCLOZOLIN Dicarboximide

PUBLICATION

UC IPM Pest Management Guidelines: Turfgrass
UC ANR Publication 3365-T
Diseases
F. Wong, Plant Pathology, UC Riverside
M. A. Harivandi, UC Cooperative Extension, Alameda Co.
J. Hartin, UC Cooperative Extension, San Bernardino Co.
Acknowledgment for contributions to the disease section:
M. E. Grebus, Plant Pathology, UC Davis

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