Powdery Mildew

Susceptible turfgrass: Kentucky bluegrass, fine-leaf fescue, bentgrass, ryegrass, and Bermuda grass.

Symptoms

• The disease first appears on the leaves as individual tufts of fine, white mycelium.

• The tufts enlarge and coalesce, causing the leaves to have a greyish-white or powdery appearance.

• Severely infected turf initially turns yellow, then tan and brown in colour.

• Infected, shaded turf can become thinned, severe infection can result in turf necrosis. 

Conditions favouring disease

• Powdery mildew is favoured by humid, cloudy weather with temperatures between 15°C and 22°C.

• It occurs in areas under stress, with low light, and with high humidity.

• Powdery mildew is also common in areas with poor air circulation, but does not require a film of water to infect turf.

Integrated turf management

• Water to alleviate drought stress.
• Avoid high levels of nitrogen and irrigation that produce lush leaf growth.
• Raise the mower height.
• Prune tree limbs to improve air circulation and the amount of sunlight.
• Convert to a polystand of shade-adapted turfgrass.

Fungicidal Control
Banner Maxx has a label recommendation for powdery mildew in South Africa.