How to Manage Pests

UC Pest Management Guidelines

Turfgrass

Stripe Smut

Pathogen: Ustilago striiformis

(Reviewed 9/09, updated 9/09, pesticides updated 12/16)

In this Guideline:


DESCRIPTION OF THE DISEASE

Plants infected with stripe smut are often pale green and stunted with long, black stripes of spore pustules. Infected leaves curl, then die and become shredded. Fungal spores formed in the leaves can contaminate seed and infect seedlings and young tillers. The fungus survives in the grass plant.

SUSCEPTIBLE TURFGRASSES

Bentgrasses, perennial ryegrass, fescues, and bluegrasses are susceptible to stripe smut.

CONDITIONS FAVORING DISEASE

Stripe smut is favored by moderate temperatures and is prevalent in spring and fall. Temperatures between 60°to 78°F are conducive to infection and symptom expression. Infected plants may die in hot, dry weather.

MANAGEMENT

Cultural Control

Infected turf is generally under higher drought stress, so irrigate adequately based upon evapotranspiration needs, but avoid extended periods of prolonged leaf wetness. Avoid excessive nitrogen fertility during the summer months.

Treatment Decisions

Apply fungicides only if the disease is severe. Seed treated with a broad-spectrum fungicide like captan can possibly prevent initial infections of seedlings.

Common name Amount to use Ag Use
REI‡
NonAg Use
PHI‡
(Example trade name)   (hours) (days)

UPDATED: 12/16
Calculate impact of pesticide on air quality
Bee precaution pesticide ratings
When choosing a pesticide, consider its usefulness in an IPM program by reviewing the pesticide's properties, efficacy, application timing, and information relating to resistance management, honey bees (PDF), and environmental impact. Not all registered pesticides are listed. Always read the label of the product being used.
 
A. AZOXYSTROBIN
  (Heritage) 0.2–0.4 oz/1000 sq ft 4 Until dry
  MODE-OF-ACTION GROUP NAME (NUMBER1): Quinone outside inhibitor (11)
 
B. CAPTAN
  (Captan 4L or 50 WP) Label rates See label Until dry
  MODE-OF-ACTION GROUP NAME (NUMBER1): Multi-site contact (M4)
  COMMENTS: Seed treatment for susceptible cultivars.
 
C. CHLOROTHALONIL
  (Daconil Action) Label rates 12 Until dry
  MODE-OF-ACTION GROUP NAME (NUMBER1): Multi-site contact (M5)
 
D. MANCOZEB
  (Fore 80WP, Dithane M-45) 4 oz/1000 sq ft 24 Until dry
  MODE-OF-ACTION GROUP NAME (NUMBER1): Multi-site contact (M3)
  COMMENTS: Dithane M-45 registered for use on sod farms only.
 
E. MYCLOBUTANIL
  (Eagle 20EW) 1.2 fl oz/1000 sq ft 24 Until dry
  MODE-OF-ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3)
 
F. PROPICONAZOLE
  (Banner Maxx) 1–2 fl oz/1000 sq ft 12 Until dry
  MODE-OF-ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3)
 
G. THIOPHANATE-METHYL
  (Fungo Flo) Label rates 12 Until dry
  MODE-OF-ACTION GROUP NAME (NUMBER1): Methyl benzimidazole (1)
 
H. TRIADIMEFON
  (Bayleton 50 Turf and Ornamental) Label rates 12 Until dry
  MODE-OF-ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3)
 
I. TRIFLOXYSTROBIN
  (Compass) Label rates 12 Until dry
  MODE-OF-ACTION GROUP NAME (NUMBER1): Quinone outside inhibitor (11)
 
1 Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of actions. Fungicides with a different group number are suitable to alternate in a resistance management program. In California, make no more than one application of fungicides with mode-of-action group numbers 1, 4, 9, 11, or 17 before rotating to a fungicide with a different mode-of-action group number; for fungicides with other group numbers, make no more than two consecutive applications before rotating to fungicide with a different mode-of-action group number.
Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Agricultural use applies to sod farms and commercial seed production.

[Precautions]

PUBLICATION

[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Turfgrass
UC ANR Publication 3365-T

Diseases

A. Downer, UC Cooperative Extension, Ventura County
M. A. Harivandi, UC Cooperative Extension, Alameda County

Acknowledgment for contributions to Diseases:
F. Wong, Plant Pathology, UC Riverside
J. Hartin, UC Cooperative Extension, San Bernardino County
M. E. Grebus, Plant Pathology, UC Riverside

Top of page


Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2017 The Regents of the University of California. All rights reserved.

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See our Home page, or in the U.S., contact your local Cooperative Extension office for assistance.

Agriculture and Natural Resources, University of California

Accessibility   /PMG/r785101711.html revised: January 12, 2017. Contact webmaster.