Microdochium Patch commonly referred to as Fusarium Patch, is top of the list of turf diseases in the UK, it occurs on 90% of golf courses at some point throughout the year. The disease is very problematic on turf grass as it can spread very quickly, causing dieback of the leaf tissue damaging the playability and aesthetics of the turf.

 

Microdochium Patch is a leaf tissue disease of turf grass which is a facultative saprophyte. This means the organism generally obtains nourishment from living matter, but it can obtain nourishment from dead organic matter too.

 

What impact does Microdochium Patch have on the turf?

 

Microdochium Patch can be a damaging disease on fine turf surfaces as the patches can adversely affect the performance of the playing surface as well as the aesthetics of the course.

 

Where is Microdochium Patch found?

 

Microdochium Patch can be found on any area of turf, especially golf greens, tees, fairways and bowling greens, as these are the areas that typically incur the most wear and tear and therefore are often under the most stress.

 

What are the signs of Microdochium Patch?

 

Microdochium Patch typically looks like a small (3.5cm diameter) reddish-brown spot in the turf that if left untreated can spread and reach up to 20cm is diameter. At times of high fungus activity, a brown ring can form around the edge of the spot and then the inner circle appears paler brown.

 

There are five stages of Microdochium Patch activity which can be seen in the diagram below.

 

Image title: Stages of Microdochium Patch infection

 

What conditions does Microdochium Patch thrive in?

 

Microdochium Patch thrives in moist conditions when temperatures are below 15.5^oC. The disease is typically seen between September and March, as it tends to occur when the rate of grass growth slows due to lower temperatures.

 

There are several stress factors that can lead to the development of Microdochium Patch, including abiotic and biotic stresses.

 

Abiotic stresses

 

Abiotic stresses are caused by non-living factors and include:

• Temperature extremes – high temperatures cause transpiration in the plant, which involves the plant emitting water vapour onto the leaf surface to cool down. Additional evaporation from the soil can lead to drought stress that weakens the plant, leaving it more vulnerable to disease
• Low solar radiation – in shared areas and during shorter days, photosynthesis is reduced due to a lack of sunlight
• Humid conditions – high levels of moisture in the air leaves the turf damp, creating favourable conditions for the disease to thrive
• Reduced air flow – this means it takes longer for the leaf to dry out
• Low mowing height – reduces the leaf area in which the plant can photosynthesise
• Poorly drained rootzones – compacted soil can be prone to poor drainage and surface water pooling, increasing moisture on the leaf

 

Image title: Abiotic stresses

 

Biotic stresses

 

Biotic stress factors are caused by living organisms:

• Disease threats – other disease threats
• Insects – such as chafer grubs or leatherjackets feeding on and damaging the plant roots
• Weeds – that compete for water, nutrients and sunlight
• Parasites – plant parasitic nematodes that feed on root systems reducing the plant’s ability to take up water and nutrients

 

Image title: Biotic stresses

 

How do I control Microdochium Patch?

 

Taking an integrated approach to disease management is key. A combination of management techniques is required to tackle disease successfully.

 

Cultural controls

 

The following cultural controls can help reduce disease pressure:

• Aeration – this helps to relieve compaction and drought stress by allowing the roots to grow deeper into the soil and take up a greater volume of water and nutrients.
• Sharp cutting blades – blunt cutting edges can tear the grass leaf tissue, leaving a large wound and greater surface area for disease to infiltrate into the plant.
• Organic matter control – practices such as scarifying, hollow coring and the application of a suitable top-dressing material will physically remove or dilute thatch and improve air movement in the rootzone. This removes a host material for disease.
• Irrigation – as Microdochium Patch favours damp conditions, it’s recommended that if irrigation is necessary, then it should be carried out at dawn to minimise the period of leaf wetness overnight.
• Keep surfaces dry – remove dew by switching or brushing.
• Correct feeding – Microdochium Patch can be encouraged by excess fertility, so it is important that nutrition is adequate, but not in excess.

 

Fungicide control

 

Chemical controls should always be the final option. If a fungicide is required, it’s important to select the correct product for the situation. However, where possible it’s always best to take a preventative approach, as the treatment is more likely to be successful and the long-term damage to the turf will be reduced.

• Dedicate
  • A broad spectrum contact and systemic turf fungicide
  • It offers preventative and early curative disease control
  • Superior penetration protects your turf inside and out
  • It is rapid-acting with proven results within two weeks of application
• Exteris Stressgard
  • Contains Stressgard Formulated Technology which helps protect the turf grass from stress factors which can leave the plant more susceptible to disease and lead to plants looking visibly healthier
  • The Stressgard Formulated Technology helps with disease management, stress management, plant health and turf colour and density
  • This fungicide offers preventative and early curative disease control
• Signature Xtra (available in Ireland only)
  • A fully systemic fungicide offering shoot to root protection
  • Contains a new active ingredient and fungicide group for the market
  • Provides preventative and early creative disease control

   

Fungicide application information

 

	Dedicate	Exteris Stressgard	Signature Xtra (only in Ireland)
Mode of action	Contact and systemic	Contact and systemic	Fully systemic
Dose rate	1l/ha	10l/ha	20kg/ha
Water volume	400-500l/ha	100-600l/ha	220-600l/ha
Applications per year	4	2	3