Drechslera
Causal Agent
Drechslera spp.
What is Drechslera?
Drechslera is turf disease growing under stressful conditions, particularly in poorly draining profiles and areas with shade issues. Early symptoms of drechslera may include the appearance of small, water-soaked lesions on infected foliage.
What are the symptoms of Drechslera?
Symptoms of Drechslera include:
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Small, water-soaked lesions may initially appear in infected foliage.
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Lesions may then become dark reddish purple to brown in colour with a yellow chlorotic margin.
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Deepening of lesions occurs until lesions become pitted and ulcerous in appearance, resulting in the angled collapse of infected leaf blades.
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Lesions are generally ovular to oblong in shape, running parallel to the leaf blade or rhizome and as they enlarge they may coalesce to blight entire leaves.
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Patchy blighted areas of turf may result in melting out of large areas, where turf becomes thin and unthrifty.
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Crown and root rot may also occur resulting in wilting and chlorosis.
Drechslera INFO SHEETWhat turfgrasses are especially susceptible to Drechslera?
Cool season turfgrasses.
When does Drechslera occur?
Conditions that are particularly favourable to Drechslera include:
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Drechslera is active year-round with a temperature range for conidia germination of 3-27°C and an optimum temperature of 15-18°C.
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The pathogen has survival mechanisms allowing it to persist through temperature extremes of hot and cold.
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Cool wet conditions are most favourable for leaf spot symptoms to occur.
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Moisture on the leaf surface is necessary for infection to occur.
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Poor air movement (high humidity in the micro-climate).
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Excessive nitrogen fertiliser.
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Excessive thatch and loose leaf clippings provide a source of food for the fungus.
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Any stress situation such as drought, herbicide injury or heavy traffic can increase the severity of the disease.
What can I do to manage or control Drechslera?
Management practices that can help control or reduce instances of Drechslera include:
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Maintaining healthy turf through proper fertilisation. Pay particular attention to potassium and nitrogen levels.
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Avoiding overstimulating the plant through excessive fertilisation, particularly of nitrogen.
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Irrigating infrequently and deeply
