Curvularia Leaf Spot
What is Curvularia Leaf Spot?
Curvularia leaf spot is usually a secondary disease after primary pathogens, such as Spring Dead Spot and Helminthosporium, have infected turfgrass. However, it can be found to cause minor disease infections on its own. When infected with Curvularia leaf spot, individual leaves initially show yellow and green dapple patterns that extend downwards from the leaf tip.
Physiological changes in the turfgrass plant can increase susceptibility to Curvularia when the light intensity is low or when the mowing height is lower than recommended for the specific situation.
What are the Symptoms of Curvularia Leaf Spot?
Symptoms of Curvularia Leaf Spot include:
Individual leaves initially show yellow and green dapple patterns that extend downwards from the leaf tip.
Infected leaves turn brown, then grey as they shrivel and die.
Irregular-shaped patches of thinned turf appear, often coalescing to affect larger areas.
Stolons and leaf sheaths may also rot.
What causes Curvularia Leaf Spot?
Curvularia Leaf Spot is caused by the fungi Curvularia spp.
When does Curvularia Leaf Spot occur?
In general, the conditions that favour Curvularia Leaf Spot are:
Areas that experience prolonged leaf wetness for several consecutive days.
Curvularia occurs at temperatures, 25-35°C.
Soil compaction and excessive levels of nitrogen and thatch.
What turfgrasses are especially susceptible to Curvularia Leaf Spot?
Wintergrass, Kentucky Bluegrass, Bentgrass, Fescue, Couch.
What can I do to manage or control Curvularia Leaf Spot?
Curvularia leaf spot can be controlled through the following management practices:
Maintain balanced fertility.
Increase the height of cut.
Avoid nitrogen applications in the spring when the disease is active.
Increase the air circulation.
Improve the drainage of the turf.
Reduce thatch accumulation