Turf Pest Mgmt Spring Dead Spot

Front 1

FYI

Successful preventive control of root diseases must begin weeks or months before foliar symptoms are expected to develop. Therefore, knowledge of past root disease development on a turf area is essential.

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Also FYI

2.With most root diseases, roots are severely diseased by the time foliar symptoms are initially expressed. Therefore, waiting until foliar symptoms develop is often too late to achieve successful control of root diseases.

Front 2

Spring Dead Spot

Spore-forming or NAH?

Back 2

Spore-forming but very difficult to find

Front 3

Spring Dead Spot

Survival / overwintering

infection

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mycelium in roots

Infects roots at 50-70F

Use HYPHOPODIA (structure formed at ends of hyphae that grow along root surface)

Front 4

Spring Dead Spot

The Ophiosphorella species killing method

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Colonizes the root cortex / vascular system increasing chance of winter kill

Only in areas exposed to 10 consecutive days with <20f

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Spring Dead Spot

Susceptible grasses

Back 5

Hybrid Bermuda

zoysiagrass

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Spring Dead Spot

Favorable environment

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Warm Fall >50F (infection of roots)

Followed by

<20F for extended periods

Compact soil with pH >6.3

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Spring Dead Spot

Symptoms

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Straw colored patches up to 2foot diameter after green-up

***Dark brow to black roots (margin of straw colored patches)

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Spring Dead Spot

Resistant species / cultivars

Back 8

common bermudagrass

Front 9

Spring Dead Spot

Cultural MGMT

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Reduce late summer - fall N application

Reduce pH (ammonium-based fert) >6.3pH

Maintain high amounts of K

Reduce that and compaction

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Spring Dead Spot

Chemical MGMT

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***fenarimol

also

azoxystrobin

Apply in fall 1-3 applications 3 wks apart