Drechslera, previously known as Helminthosporium, has once again reared its head in Manitoba. Symptoms may be seen in the leaf, crown, or root of the lawn grasses. Commonly known as “melting spot”, the diseased sections of grass may give the appearance of either dog urine burn or heavy amounts of thatch.
If you water your lawn excessively; this creates an environment that Drechslera may thrive in. The use of Daconil or Scotts Lawn Care Fungicide can be useful, but just changing some maintenance habits can help prevent the problem. Watering in the morning to mid-day is recommended, as watering during the evening does not allow the water enough time to be absorbed or evaporate. High humidity promotes the growth of the disease. Lawns should be cut to 5- 6 cm. (2-3 inches) long and remove as much thatch as is possible.
Some cultivars may be resistant to Drechslera such as F. rubra or L. perenne, so ask your local garden center if they carry any seed that has these as part of the mix.
Samples can be brought to the third floor of the Brodie Science Building at the Brandon University for identification free of charge.
Compiled by: Dr. Bill Paton and Jonathan Bush