Leon Lee Burpee

Biology of Turfgrass Diseases Incited by Rhizoctonia Species

Turfgrasses are those members of the family Poaceae (Gramineae) characterized by a dense foliar canopy and tolerance to mowing. Approximately 40 species in 18 genera represent two physiological groups commonly referred to as cool-season and warm-season grasses. Cool-season grasses are adapted to subarctic and temperate regions, with optimal growth occurring at 15–25°C. These species, known as C3 grasses, undergo photosynthetic carbon fixation through the Calvin cycle. In contrast, warm-season grasses are known as C4 grasses because they fix carbon via the Hatch-Slack pathway. These grasses are adapted to tropical and subtropical regions, with optimal growth occurring at 25–35°C (Smiley et al., 1992).