Scientific name
Bipolaris spp., Drechslera spp. and Exserohilum spp.
Common Names
Leaf Spot, Helminthosporium Leaf Spot
Leaf Spot is a common fungal disease affecting both cool-season and warm-season turfgrasses throughout Australia. It develops during warm, humid weather and prolonged leaf wetness, particularly in stressed or over-fertilised turf. Early symptoms appear as small purple, brown or black spots on grass blades, which can enlarge and merge, causing thinning turf and, in severe cases, crown and root infection known as "melting out."
Similar Diseases
- Dollar Spot (Clarireedia spp.)
- Brown Patch (Rhizoctonia solani)
- Gray Leaf Spot (Pyricularia grisea)
- Melting Out (Bipolaris spp.)
SCENARIOS AND SOLUTIONS
At the first signs of leaf spotting: Apply Indigo AzoForce 250SC Fungicide 2.5L to protect healthy turf and limit further disease development.
On sports fields and golf courses during warm, humid weather: Apply Indigo AzoForce 250SC Fungicide 2.5L preventatively before extended periods of leaf wetness.
In lawns with recurring Leaf Spot: Improve airflow, water early in the morning, and include Indigo AzoForce 250SC Fungicide 2.5L in a preventative fungicide program.
Where turf is thinning from severe infection: Apply Indigo AzoForce 250SC Fungicide 2.5L promptly and reduce plant stress through balanced irrigation and nutrition.
References
https://www.turffiles.ncsu.edu/diseases-in-turf/leaf-spot-in-turf/
https://www.umass.edu/agriculture-food-environment/turf/fact-sheets/leaf-spot-diseases-of-turf
https://ipm.ucanr.edu/agriculture/turfgrass/leaf-spot/
Leaf Spot photo courtesy of Will Bowden
