At Cleveland Golf Club, Redcar, North Yorkshire we noticed patches of light green or sickly yellow grasses with the basal rotting away on the 12th and 17th green in the winter of 2005. Minute black structures (acervuli) were also seen at the base of the grass.
This was diagnosed as Anthracnose.
Anthracnose can be observed throughout the year, but it is more prominent when the grass is growing slowly.
Anthracnose can be seen as being beneficial in some ways, in that, it only hits the Annual Meadow Grass species and in theory would leave only finer grasses behind.
In the USA anthracnose is separated into two types, although it has been reported as such in the UK:
1) Anthracnose foliar blight, which affects the outer leaf tips and gradually works inwards. If left untreated this can advance to basal rot.
2) Anthracnose basal rot, which destroys the base of the grass making it easy to pull out of the sward. The foliage is affected after the basal rot has commenced. This is much more serious than foliar blight.
Conditions favourable to the disease
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Compacted turf | |
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Increased plant stress due to more usage and intensive maintenance; | |
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Low nitrogen levels; | |
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Humid weather - warm and cool; | |
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Thatchy, moisture retentive turf; | |
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Poorly drained rootzone; | |
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Low mowing heights causing undue plant stress; | |
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Poorly set mowers and blunt blades. |
All these conditions and practices were prevalent on the greens at Cleveland when I took over and there was no real surprise when the Anthracnose reared its head.
Control measures
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Keep the soil well aerated; |
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Move pin positions more regularly; |
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Spread wear for entry and exit points on golf greens; |
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Improve the drainage system. |
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Reduce thatch layers - both depth and density of them; |
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Improve air circulation around the area: Consider thinning hedges, trees etc., removing overhanging branches; |
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Ensure soil potassium levels are appropriate, especially if the turf appears stressed during the summer period. |
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Reduce Poa annua content of a sward; |
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Provide a more acidic soil to discourage annual meadow grass; |
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Use sulphate of iron on a regular basis to promote surface acidity; |
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Set mower correctly and ensure the blades are sharp; |
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Apply a nitrogen fertiliser, although no later than August on golf greens; |
All the above control measures were employed along with a combined contact and systemic fungicide that controlled the initial outbreak.
This year we have had no outbreak of Anthracnose and this we put down to an intensive aeration programme combined with the fact we have changed the grass composition greatly to try and reduce the % of annual meadow grass in the sward.
Aeration was carried out to these 2 greens as soon as we got the opportunity and took the form of Verti-draining and rolling to bring the surface back into play as soon as possible.
