S. TUDSRI¹, H. MATSUOKA² and K. KOBASHI²

¹Department of Agronomy, Kasetsart University, Bangkok, Thailand
²Department of Animal and Grassland Research, National Agricultural Research Center for Kyushu and Okinawa Region, Kumamoto, Japan

Abstract

Five cultivars of guinea grass (Panicum maximum) (TD 58, Gatton, Natsukaze, Natsuyataka and Natsukomaki) were studied in the controlled-environment room at the National Agricultural Research Center for Kyushu and Okinawa Region, Kumamoto, Japan for 6 weeks following seedling emergence. All the guinea grass cultivars were grown at 3 temperature regimens, viz. 25/15, 30/20 and 30/25°C day/night. The objectives of this experiment were to determine the response of guinea grass cultivars to different seasonal temperature conditions. The results showed that the growth and development of all cultivars in terms of plant height, leaf area and plant dry matter yield were severely reduced at the lowest temperature (25/15°C). All cultivars responded to increasing temperature between 25/15 and 30/20°C for all attributes, except tiller number and leaf number. In terms of leaf area and total plant dry weight, cultivar Natsukaze had the best performance under low temperature followed by cultivar Natsukomaki. All cultivars grown at 25/15°C had higher N, Zn, Mn, and Cu concentrations than at 30/20 or 30/25°C while I and Co were variable.
Under field conditions in Thailand at 3 months after planting in the cool season, Natsukaze produced the highest dry matter yield followed by TD 58, Gatton and Natsuyataka.