後藤, 英司

古在, 豊樹

西村, 将雄

田口, 勝教

石神, 靖弘

GOTO, Eiji

KOZAI, Toyoki

NISHIMURA, Masao

TAGUCHI, Katsunori

ISHIGAMI, Yasuhiro

[SUMMARY]Tomato seedlings were grown in plug trays at three planting densities (700, 1100, or 1600 m-2) under two air current speed conditions (0.3 or 0.7 m s-1) either in closed transplant production system or in a greenhouse without air current speed control. The growth and that uniformity of the tomato plug seedlings decreased with an Increase in the planting density in the closed transplant production system. At the higher air current speed, the growth increased without a decrease in the growth uniformity and excessive stem elongation. The growth and that uniformity of seedlings grown in the closed transplant production system were greater than those of seedlings grown in the greenhouse. These results indicate that the closed transplant production system under the higher air current speed condition enabled transplant production using plug trays with higher planting densities than those in the greenhouse. The environments in the closed system and greenhouse were measured and compared. Based on the results, high integrated light intensity and light sources with a high red to far-red ratio in the closed system appeared to be the reasons for the decrease in excessive stem elongation and increase in growth uniformity when compared with those in the greenhouse.