To reduce Helminthosporium diseases in turf, which practice is recommended?

• A. Plant a mixture of cool-season cultivars
• B. Apply fungicides
• C. Use only warm-season cultivars
• D. Increase mowing height dramatically

Answer: (A)

Introducing genetic diversity in a turf stand by planting a mixture of cool-season cultivars helps slow Helminthosporium diseases. When the stand is a mixture, not all leaves are equally susceptible. A pathogen that spreads through a uniform, all-susceptible canopy finds it harder to move far or reproduce quickly because some leaves resist infection or support it less effectively. That breaks up the epidemic and lowers overall disease levels, giving the turf a more resilient, healthier appearance over time.

While fungicides can control the disease, relying on a mixed cultivar approach targets the problem at its source—diversity reduces the potential for a single pathogen to dominate. Using only warm-season cultivars wouldn’t address typical Helminthosporium issues in cool-season turf, and drastically increasing mowing height isn’t a targeted solution for this disease.