抄録
In this study, the differences in plant growth and canopy surface temperature (Tc) among three different cultivars of sugar beet : “Monohikari”, “Amahomare” and “Hokkaimitsuboshi” were investigated and the relationship between them was analyzed.
The result showed that leaf number differed significantly among cultivars and “Hokkaimitsuboshi” showed the highest leaf number and increase rate. Plant length also differed among cultivars, with “Monohikari” showing the highest. It was speculated that the highest plant length of “Monohikari” might have caused the highest leaf area index values among cultivars. SPAD also had varietal differences and all cultivars had been changing over 40 by 101 DAT, after which all the cultivars decreased to below 35.
Diurnal variation of Tc was maximal around noon and the maximum difference among cultivars was about 2°C. These differences of Tc among the cultivars increased with increasing vapor pressure deficit. Comparing the 6 hours mean Tc value from 10 to 16 o’clock, “Monohikari” had the highest while “Amahomare” had the lowest, and the maximum difference was about 1.7°C.
