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transcript
© Myerscough College 2011
J Kno
wles@
myers
coug
h.ac.u
k
Turf G
rass D
isease
Man
agem
ent
The management and control of turf grass diseases starts with the principle understanding of the disease triangle. By understanding and managing the turf environment through physical and cultural applications the use of chemical pesticides can be reduced. This session book promotes working towards sustainable and integrated pest management. The cause and effect of diseases as well as fungicids are detailed here. This session is relevant for the QCF Units 210 (L5.1), 350 (CU80), & NVQ CU110
THIS IS A DRAFT DOCUMENT. THE FORMAT AND
GENERAL IDEA IS UP FOR REVIEW.
Myerscough College St Michaels Road, Bilsbarrow, Preston,
England 01995 642222
enquires@myerscough.ac.uk
©Myerscough College 2011
1
Turf Grass Disease Management The Disease Triangle
Disease symptoms occur on grasses as an effect of three associated causes.
These causes are: environmental conditions, type of pathogen and the type of host.
This can be best illustrated as the Disease Triangle.
STRETCH YOUR KNOWLEDGESTRETCH YOUR KNOWLEDGESTRETCH YOUR KNOWLEDGESTRETCH YOUR KNOWLEDGE
� Pathogen is the fungus that attacks the grass plant.
� Environment is the weather, the climate, the micro-climate, turf
environment, and soil environment.
� Host is the particular species of grass.
Symptoms
Host
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A combination of a pathogen, with a favourable environment and an available
host can results in the disease. For example in this cause and effect diagrams;
The disease can change by even a subtle change to one of the causes, as
shown immediately above. Pink Snow Mould, has the same pathogen, same host,
with slightly differnet enviromental conditions to Microdochuim Patch. As the name
suggests, Pink Snow Mould usually occurs under and after a snow covering.
Environment
Temperatures between 0oC to 20oC
Damp
Drizzle
Rasied soil pH
Poor surface drainage
Thatch
Pathogen
Microdochium nivale
Note: for the purposes of diseases analysis the pathogen should always be considered to be available
Host
Annual Meadow Grass
Bent grass
Disease:
Microdochium Patch
Environment
Temperatures between -20oC to 20oC
cold
Rasied soil pH
Poor surface drainage
Thatch
Pathogen
Microdochium nivale
Note: for the purposes of diseases analysis the pathogen should always be considered to be available
Host
Annual Meadow Grass
Bent grass
Disease:
Pink Snow Mould
©Myerscough College 2011
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Integrated Pest Management It is important to control diseases, especially the diseases that are
detrimental to the playing surface. Grasses are subject to many diseases and
disorders, some are not a problem to sports turf, while others can result in bare
areas and loss of surface.
Reporting and inspecting for diseases is an important part of groundsmanship
and greenkeeping. Inspecting the turf is about being vigilant. There are good
opportunities for inspecting the turf health, for example; while out cutting, changing
holes, divoting, and switching.
By immediately reporting any signs of disease to a senior member of the team
it can save time, resources and money. Importantly, the quality and integrity of the
playing surface can be upheld. This close monitoring forms the essence of an
integrated management control for diseases. The procedure for controlling diseases
is illustrated below. This procedure also forms part of an Integrated Pest
Management (IPM) monitoring role.
Importantly, this procedure is not exclusive to pesticide application and treatment
must be interpreted as cultural, physical and chemical.
Identification &
record
report to an
appropriate person
identification
confirmed by
appropriate person
treatment planning.
Including risk,
LERAP and COSHH
assessments
record details of
treatment
review the
effectiveness of the
treatment
©Myerscough College 2011
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Treatments Controlling and managing the onset of any threat to turf health is the
continuing role of the Greenkeeper and Groundsman. The head Greenkeeper or
groundsman will spend much of their time planning and preparing the surface for
play and continued (sustainable) health.
Physical Many tasks and routine operations are considered as pro-active physical and
cultural management against the onset of a turf health threat. Here are examples of
physical controls, clearly these are not distinct from cultural methods:
• aeration • switching
• top-dressing • scarifying
• drainage installation • cutting blades are sharp
Cultural By changing the culture of the turf it is described as a cultural treatment. For
example; introducing grass species that are resistant or less susceptible to the
diseases that are most detrimental to sports turf, see the susceptible Species
section. Increasing the beneficial soil bacteria (organic fertiliser) populations to
antagonise pathogenic fungi has been proven as a method to reduce disease
incidence.
Plant Protection Products (Chemical) The use of plant protection products include the use of pesticides, otherwise
known as a chemical control. There are additional chemicals that are not pesticides
that are used to control fungi. An example of this is the application of surfactants
(wetting agents).
All use of pesticides as defined by Chemicals Regulation Directorate, will need
applying and recording in line with the relevant legislation and codes of practice e.g.
the Control of Pesticides Regulations Act.
These methods of treatment are linked with the associated causes as
described on page one. By intervening on the associated causes it can disrupt the
association and prevent disease onset.
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Susceptible Species The following table gives an overview of diseases along with the species that
are susceptible.
STRETCH YOUR KNOWLSTRETCH YOUR KNOWLSTRETCH YOUR KNOWLSTRETCH YOUR KNOWLEDGEEDGEEDGEEDGE
Diseases of turfgrass are can either be bacterial, viral or fungal. Here we are mainly
concerned with fungal infections as these are most common in sports turf. The
facultative parasitic fungi of turf obtain their nutrition from the host plant, in many
cases of the diseases will die when the host plant dies. Saprophytic fungi (Fairy ring
and Thatch Fungus) feed on decaying organic matter, such as underlying decaying
tree roots and thatch.
Disease
Susceptible Turfgrasses*
Poa
pratensis
Poa annua
Agrostis
stolonifera
Agrostis
capillaris
Festuca
rubra ssp.
Lolium
arundinaceu
m
Lolium
perenne
Anthracnose x xx x xx xx
Brown Patch x xx xx xx x xx xx
Fairy ring x x x x x x x
Leaf spot xx xx xx x xx x x
Microdochium Patch x xx xx xx x x x
Phythium Blight x xx xx xx x x xx
Pink Snow Mould x xx xx xx x x x
Red Thread xx x x xx xx
Stem Rust xx x x x
Take-All Patch xx xx
Thatch Fungus (disorder) x x x x x x x
Yellow Tuft x x x x x x x
*
X Susceptable under certain conditions or of minor importance
XX Disease is of primary importance
Adapted from: Turgeon, A. 1996. Turfgrass management (4th Ed.) p.258-259
©Myerscough College 2011
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Fungicides The following table is an overview of the common fungicides that are
protective and curative against turfgrass diseases. The fungicide product label will
give detailed information on application rates and which diseases it can control.
If unsure, as to the identity or which chemical to use it is advisable to seek
the advice of a BASIS registered Turfgrass Agronomist.
Active Ingredient Mode of Action
Chlorothalonil
contact
Iprodione
local penetrant
Inhibits spore germination and growth
Pyraclostrobin
local penetrant
Prevents electron transfer in mitochondria – leads to insufficient energy and so prevents growth
Trifloxystrobin
local penetrant
Carbendazim
Acropetal penetrant
Affects fungal cell division – prevents growth and germination
Thiophanate-methyl
Acropetal penetrant
Fenarimol
Acropetal penetrant
Disrupts ergosterol production – prevents growth
Mycobutanil
Acropetal penetrant
Azoxystrobin
Acropetal penetrant
Prevents electron transfer
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Summary The principle of the diseases triangle is the underpinning knowledge for
sustainable turf management and applying the fundamentals is the basis for
Integrated Pest Management.
By understanding and managing the turf environment through physical and
cultural applications, the use of chemical pesticides can be reduced.
Fundamental skills in turf disease identification are necessary skills for the
modern Greenkeeper and Groundsman. Along with good skills in identifying turf
diseases accurately, it is also necessary to know the integrated management controls
to reduce disease incidence.
Links The UK Turfgrass Disease Centre
http://www.ukturfgrassdiseasecentre.co.uk
Penn State Univesity (Managing Turfgrass Diseases)
http://cropsoil.psu.edu/turf/extension/factsheets/managing-diseases
Bibilography Turgeon. A. 1996. Turfgrass management (4th Ed.). Prentice hall
York, C. 1998. Turfgrass Diseases & Associated Disorders. STRI
Mann, R. 2009. Approved Turfgrass Fungicides. STRI (accessed online 28/10/11)
©Myerscough College 2011
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Author Jonathan Knowles is a Training Co-ordinator working in the Skills & Enterprise
Directorate at Myerscough College. Contact Jonathan on email;
jknowles@myerscough.ac.uk , or by phone 01995 642222.