Development of a Biological Control for Turfgrass Snow Molds: From the
Laboratory to a Commercial Product
Dr. Tom Hsiang, Dept. Environmental
Biology, University of Guelph
Snow molds
- fungi which grow at low temperatures
often under snow cover, and can damage plants
- turfgrass snow molds include:
- Grey snow mould / Gray snow
mold
- Typhula incarnata
(Tinc) - Typhula ishikariensis
(Tish)
- Pink snow mould/mold
Gray snow mold
- caused by Typhula ishikariensis
(Tish) and Typhula incarnata (Tinc)
- attack grasses and cereals
- require > 90 days of snow cover for severe disease
Gray snow mold on perennial ryegrass
Gray snow mold on Kentucky blue
Gray snow mold on creeping bentgrass
Gray snow mold (Tish sclerotia on CB)
Sclerotium (sclerotia - plural): a compact
mass of hyphae, often with a dark rind capable of surviving unfavorable
conditions.
Gray snow mold (Tish sclerotia on
CB)
Gray snow mold (Tinc sclerotia on
PR)
Gray snow mold (Tinc sclerotia on
KB)
Gray snow mold (Tinc sclerotia)
Pink snow mold
- caused by Microdochium nivale
(MN) which also causes Fusarium patch (Microdochium patch)
- attacks grasses and cereals
- requires snow cover and long wetness periods for round patches to
form on turfgrasses
Pink snow mold on creeping bentgrass
Pink snow mold on Kentucky blue
Pink snow mold on perennial ryegrass
Pink snow mold - pink foliage of KB
Pink snow mold - sporodochia on KB
Pink snow mold - spores
Pink or gray snow mold?
Snow mold control
Snow molds - chemical control
- commonly controlled on turfgrass with
heavy metal & chlorinated fungicides
- mercury fungicides (No longer
legal in Canada as of December 2000)
- quintozene (pentachloronitrobenzene): deregistered in US Aug 2006
- Arrest (mixture of thiram,
oxycarboxin, carbathiin)
Snow molds - chemical control
- The costs of applying these synthetic
fungicides coupled with environmental concerns requires alternative management
approaches
- Pesticide bans across the country
Snow molds - other controls
- cultural techniques may reduce the
severity of snow mold diseases, but cannot entirely prevent their occurrence
- composts have been found to reduce snow molds, but the compost material
is variable and results are sometimes variable
Discovery of the biocontrol agent
- In the 1980’s, two research groups
independently discovered that Typhula phacorrhiza (TP) could suppress
snow mold
- Lee Burpee (Univ. Guelph)
- Now Matsumoto (Japan)
- By 1990, both
researchers had left snowy areas and moved to warm areas without snow mold
- Our research started in 1993 on biocontrol of snow molds
- TP is a saprophyte found all over the world
Corn stubble after winter
Typhula phacorrhiza sclerotia
TP objectives (1994-1998)
- collect hundred of isolates of TP
- test isolates in the lab for growth and production of sclerotia
- test isolates in the field for snow mold control
Sample sites in Ontario
Applying inoculum
Snow fence
At snowmelt
Results
- > 300 TP isolates
- large variation (TP snow mold suppression)
- best TP isolates
- active against Tish or
Tinc
- not pathogenic to grasses
Plots inoculated with Tish or Tinc, 95
Plots inoculated with Tish or Tinc, 96
Plots inoculated with Tish, 97
Plots inoculated with Tish or Tinc, 97
Objectives (1998-2004)
- TP efficacy trials across Canada
- develop a formulation for TP
- prepare a registration package for TP
Efficacy Results
- Suppression of pink snow mold by TP
in Ontario
- in trials near Barrie (natural
inoculum) and Guelph (inoculated), pink snow mold was suppressed
Efficacy Results
- Residual efficacy of TP on creeping
bentgrass
- 5 years of field testing
- a single application of TP suppressed gray snow mold disease for
the next 3 years, but efficacy declined over time
Registration Package
- Pest Management Regulatory Agency (PMRA,
Health Canada) requires the following information for pesticide registration
- product characterization
- environmental toxicology of product
- human and animal toxicology of product ($$$)
- efficacy of product
Registration Package: product characterization
Registration Package
- Environmental toxicology
- non-target effects (pathogenicity
to grasses)
- persistence of sclerotia
- DNA probes to track fate in the environment
Registration Package
- Human and animal toxicology
- very costly
- necessary for this product???
Registration Package
- Performance & Efficacy
- trials established across Canada
(1998-2004)
Rocky Mountains
Rocky Mountains Site II (May 2000)
Rocky Mountains Site II, TP trial, May 2000
May 2000. Green plots treated with TP in Oct 1999
Summary of Results
- 32 trials across Canada from 1999 to
2004
- in 14 trials, insufficient disease
pressure or too much abiotic (climate) winter injury
Summary of Results
- in 12 trials, the biocontrol agent
suppressed snow molds as well as or better than fungicides
Summary of Results
- in 6 trials, the biocontrol did not
suppress snow molds as well as the fungicides
Future Research
- better formulations
- better TP production methods
- search for better isolates
Current Status (Fall 2008)
- commercial partner has been able to
find an agency to produce the inoculum in mass culture
- registration package being submitted to PMRA
- tests in Guelph, Barrie area & Banff F08
We hope to have a product for the turf industry
in the near future
TP Funding
- 1994-1998 (CDN$30,000/yr)
- Canadian Turfgrass Research
Foundation
- Ontario Ministry of Education
- 1998-2004 (CDN$70,000/yr)
- Canadian Turfgrass Research
Foundation
- Nu-Gro Corporation
- Natural Sciences and Engineering Research Council of Canada
- TOTAL: over half
a million dollars
What was the money for?
- 75% Wages for techs and students
- Postdocs $35,000/yr
- Technicians $30,000/yr
- Students $17,000/yr
- 10% Materials
and supplies
- 5% Field work and meetings
- 10% University overhead
Was it worth this cost?
- consider that development of a synthetic
fungicide (from initial lab tests to bringing it to the field) often costs
millions of dollars
- consider that some of the synthetic fungicides used to control snow
molds may soon be de-registered
- consider the societal sentiments against synthetic pesticide registration
Thank you for your attention
Contact me if you have questions (thsiang at uoguelph.ca)