Kyllinga species are becoming more prevalent in turfgrass sites throughout North America. The effects of nitrate (50, 200, and 400 mg L−1), temperature (33/24, 25/17, 19/11 C day/night, respectively), and light on seed germination of three Kyllinga species were investigated in growth chambers. Nitrate concentrations did not stimulate Kyllinga species seed germination compared with untreated seeds. All Kyllinga species seeds failed to germinate in darkness but resumed germination once they were placed in light. This is an important pest management strategy because a dense, uniform turfgrass stand with its minimum light penetration to the soil would minimize Kyllinga species seed germination. Higher temperatures increased seed germination rate and percentage of each species after 8 wk. Maximal (> 90%) K. brevifolia germination occurred 2 to 4 wk after initiation in every seed study, whereas K. squamulata seeds germinated continuously. Minimal (< 10%) K. pumila seeds germinated until alternating diurnal temperatures were imposed.

Kyllinga species are becoming more common throughout the southeastern United States. Two species, Kyllinga brevifolia and Kyllinga squamulata, in particular are prevalent weeds in turfgrass. To better understand these weeds, growth chamber studies determined the growth of K. brevifolia, K. squamulata, and Cynodon dactylon × Cynodon transvaalensis as influenced by three temperature regimes (33/24, 25/17, 19/11 C day/night, respectively). Temperature influenced almost all aspects of Kyllinga species growth. Plant height of both Kyllinga species increased nearly twofold after 8 wk at high temperatures. Plants were mowed each week to 2.5 cm; both species produced more than twice as many clippings by 8 wk at high (33/24 C) temperatures than at low (19/11 C) temperatures. Destructive analysis at 8 wk revealed that K. brevifolia shoot and root weight increased with decreasing temperature, whereas K. squamulata shoot and root weights were not affected by temperature. Shoot weight percentage for both Kyllinga species increased from 59% in medium temperatures to 69% in high temperatures. K. brevifolia shoot weight percentage decreased to 53% in low temperatures, whereas K. squamulata shoot weight percentage increased to 72%. K. brevifolia inflorescences formed at 2, 3, and 5 wk in high, medium, and low temperatures, respectively, whereas K. squamulata flowered immediately in all temperatures. C. dactylon × C. transvaalensis and Kyllinga species growth were similar within each temperature regime throughout the 8-wk study.