Freeze tolerance of plants is not constitutive but induced in response to low, nonfreezing temperatures (< 50 F (10C). This process is known as cold acclimation, which occurs during the fall or early winter, and explains why a plant species growing at a warm temperature then exposed to freezing is killed, while that same plant exposed to a cold acclimation period prior to sub-freezing temperatures survives.
Intermittent ice formation on golf greens and fairways is a common event in northern temperate regions. Continual ice cover that persists for an extended time can cause injury to certain species of turfgrass. In addition the re-freezing of water into ice during freeze - thaw cycles during late winter/early spring can result in freeze injury. In this article the formation of ice and how it can cause injury is discussed.
The cool wet weather of spring and fall is ideal for the development of Helminthosporium leaf spot on bermudagrass. The disease appears as small brownish spots normally 2 to 3 cm in. The spots may coalesce forming large blighted areas. The pathogens that may cause this disease were once grouped as Helmithosporium leaf, crown and root diseases (1). The pathogens that cause leaf, crown and root diseases on warm season turfgrasses like bermudagrass are Bipolaris species (ex. B. cynodontis, B. spicifiera, and B. sorokiniana).