Abstract
The effects of controlling minimum nocturnal ambient air temperature, day length and culture medium temperature on growth and yield were studied for the purpose of developing a year-round cultivation system for wasabi (Eutrema japonica (Miq.) Koidz.) . When the minimum night temperature was 5°C in winter, the growth of wasabi leaf was slow but recovered when the temperature rose to 8°C. Extension of day length by supplemental lighting was found to enhance growth recovery. Wasabi was planted at different times of the year to compare the effects of seasonal variation on stem growth. The mean daily growth medium temperature was maintained at 13.5-28.1°C throughout the year. These results revealed little difference in growth and stem pungency due to the season of planting, and stems grew to about 60 g within two years of cultivation. Year-round, stable nutrient solution cultivation of wasabi under environmental control may be an economically feasible alternative to conventional, labor-intensive cultivation systems.
