Spring Dead Spot
Causal Agent
Leptosphaeria korrae
What is Spring Dead Spot?
Spring Dead Spot is typically a disease of mature turf that is intensively managed. Spring dead spot causes circular patches of bleached, straw coloured dead grass to appear in spring as the dormant grass regrows.
What are the Symptoms of Spring Dead Spot?
Symptoms of spring dead spot generally include:
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Circular patches of bleached, straw coloured dead grass appear in Spring as the dormant grass resumes growth.
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Patches are also visible in Autumn and Winter after a series of unusually cool days or wet, cold weather. These patches may range from a few centimetres to 1m in diameter. They can reappear and expand in the same spot for 3 or more years.
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After 2 to 3 years, the centres of active patches may remain alive, and the patch takes on a “ringlike” appearance.
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Rings that coalesce can appear as serpentine arcs.
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Roots of affected plants turn dark brown to black and are severely rotted.
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Regrowth of grass into affected patches is slow and patches may remain barren of fill with weeds.
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When the grass recolonises an affected area it remains stunted.
Spring Dead Spot INFO SHEETWhat turfgrasses are especially susceptible to Spring Dead Spot?
Common couch grass, South African couch grass and their hybrids.
When does spring dead spot occur?
The conditions favouring spring dead spot are:
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Most active when temperatures are cool (12 to 14°C) and soil is moist.
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Roots of Couch grow most rapidly at 24 to 29°C and extremely slowly at 15°C, thus the fungus has a competitive advantage at low temperatures.
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Spring Dead Spot favours cool, wet weather in the spring and autumn and daily temperatures of less than 15°C.
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This disease is typically found where thatch is more than 1.2cm thick and in locations with poor drainage and low potassium levels.
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Heavy applications of nitrogen in late summer often increase disease severity the following spring.
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Spring Dead Spot is more severe on turf that is over three-years old and in locations with long dormancy and cold temperatures.
What can I do to manage or control Spring Dead Spot?
Turf management practices that can help control or reduce instances of spring dead spot include:
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Preventative systemic fungicide applications.
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Good fertiliser management especially nitrogen and potassium.
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Control weeds in affected turf to enhance recovery from Spring Dead Spot.
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Apply moderate to high levels of phosphorous, potash and minor elements.
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Improve drainage of turf.
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Reduce thatch
