Common Winter Diseases
Cold, moist weather is conducive for a myriad of diseases on warm- or cool-season grasses. This article will discuss some of the turfgrass diseases you might be seeing this winter.
Desiccation
Desiccation in the wintertime is the result of dry conditions, rather than wet. This effect is commonly seen year-round in areas prone to run-off, little rain or snow cover, or in arid climates. Turfgrass loses more water than it can take up, and appears to be dark brown as if it is still in dormancy. However, when a dry spell is expected, it is important to examine the level of desiccation. While tissues can be damaged, blade tissues are more regenerative than the crown where desiccation should not.
Leaf Spot (Drechslera and Bipolaris spp.)
Seen often in bermudagrass, leaf spot is a disease of the blade caused by light brown splotches along the blade with darker brown outer rings. Controlling this disease is best done early in the disease’s development. If left unmanaged, the pathogen could reach the crown of the turf and cause a larger problem in the warmer months called ‘melting out’. When temperature ranges between 60 and 65oF, moisture is prolonged, and air movement within the stand is minimal, and early signs of leaf spot can appear.
Leaf spot can be reduced by:
- Aerating to reduce thatch and improve drainage
- Increase mowing heights
- Fertilize with the yearly recommended rate of nitrogen
- Chemical application when symptoms arise or preventatively