Effect of Environmental Conditions on the Growth of Four Perennial Grasses. I. Response to Controlled Temperature¹

Abstract

The growth of timothy (Phleum pratense L.), bromegrass (Bromus inermis Leyss.), orchardgrass (Dactylis glomerata L.), and Kentucky bluegrass (Poa pratensis, L.) was studied under controlled temperatures varying by 3.3 C intervals from 18.3 to 34.8 C during the day and from 1.8 to 18.3 C during the night. A day temperature between 18.3 and 21.6 C was optimum for top growth with timothy, orchardgrass, and bluegrass. With bromegrass, the optimum day temperature was between 18.3 and 24.9 C. As the day temperature was increased from these optimum ranges to 34.8 C, all of the species decreased in yield, but the decrease in bromegrass yields was less than in any of the other species. In some cases, night temperature also affected yields; but the optimum night temperature depended upon the species and the day temperature. The dry weight of etiolated growth indicated that the level of food reserves varied greatly. The species ranked orchardgrass > bromegrass > bluegrass > timothy for level of reserves. The most important factor affecting the level of reserves in a particular species was night temperature. In general, the food reserves decreased as the night temperature was increased from 1.8 to 18.3 C.

Effect of Temperature on Growth of Five Subtropical Grasses. I. Effect of Day and Night Temperature on Growth and Morphological Development

“…In temperate species, such as Buomus, Phleum, Poa and to a lesser extent Dactylis, no clear optimum day/night temperature combinations were obtained (Baker and Jung 1968), although in Phalauis and Festuca species, respective apparent optimum daylnight temperature combinations of 24119°C (Scurfield 1963) and 23117°C (Robson 1973) were obtained.…”

Heat Tolerance of Kentucky Bluegrasses, Perennial Ryegrasses, and Annual Bluegrass1

“…Above 24 C, growth subsides first and then at very high temperatures, severe injury or death can occur. In controlled environment pot experiments, Kentucky bluegrass (Poa pratensis L.) produced maxi· 79 mum dry weight of top growth at 21.6 C, and growth declined as temperature was increased to 24.9 C, Baker and Jung (1968). Plants grown at 34.8 C produced less than half the top growth of those at 21.6 C. Julander (1945) observed that Kentucky bluegrass was killed when exposed to 48 C for 16 hours.…”

“…The relative im· portance of the two in turfgrass culture is not known. Several studies have been done on the influence of prolonged periods of moderately high temperature on turfgrass growth (Baker and Jung, 1968;Watschke et al, 1972;Pellett and Roberts, 1963). Less information is available on the effects of short exposure to high temperature.…”

Development and validation of a dynamic model of growth and quality for cool season grasses

“…They also found the optimum temperature for growth to be 18.3 ºC, and stated that day temperature had a greater influence on growth than night temperature. Baker & Jung (1968a) noted a significant decline in smooth brome growth as day temperature increased from 31.0 to 35.0 ºC.…”