砂丘地におけるラッキョウ生産と気象環境

he growth and yield on rakkyo together with meteorological environmental factors occuring in its field were investigated at Fukube Village，Tottori Prefecture from April to May，1981. The investigated data were compared between south-facing and north-facing fields. The growth and yield in the south-facing field were better than those in the north-facing field. The South/North ratio (S/N ratio) for the multiplication of the number of bulbs was 1.41 per bulb，and for the weight was 1.13 per bulb. The leaf S/N ratio per bulb showed 1.52 in the number on leaves and 2.62 in the leaf fresh weight. ln the south-facing field air temperature and solar radiation were higher and relative humidity was lower than in the north-facing field. The average maximum air temperature at 15cm height which is the vegetation position，was 3.6℃ higher in the south-facing field than in the north-facing field at 20℃，2.6℃ higher at 30℃. Also，the solar radiation in the south-facing field showed c.10% higher，although the difference between the south and north decreased with the rise of solar altitude.