Abstract
Two clones (BL : broad-leaf and NL : narrow-leaf) of orchardgrass were grown under combinations of 2 photoperiods (SD : 8hr natural light and LD : SD+8hr supplemental light with 40 watt incandescent lamp) and 4 air-temperatures (day-night 30-25°, 25-20°, 20-15°, 15-10°C) for 20 days, after which all plants were cut 3 cm high and moved to a greenhouse, where the regrowth processes were observed during 115 days for 3 successive cuts. The growth in terms of plant height, leaf number and weight of cut herbage during pretreatments was greater under long day and higher temperatures. However, the 1st and 2nd regrowths thereafter were greater when pretreated with SD and lower temperatures, probably due to higher photosynthesis by the larger and darker green leaves formed after cut caused by the increased assimilates accumulated at the stubble and roots under these conditions.
