Effects of Cell Shape of Plug Trays on Shoot and Root Growths of Chinese Cabbage[Brassica campestris L. (pekinensis group)] Transplants.

Abstract

The effects of cell shape of plug trays on shoot and root growth of Chinese cabbage 'Fuyu Touge' transplants were investigated. The cell shapes were : round, pentagonal, square, and triangular ; holding equal volumes of the growing medium. Root circling of the plug transplants was fastest in round cells and slowest in triangular ones. At the second leaf stage, roots grew better in round cells, had higher N and K contents and respiratory activity than did those of other shapes. No significant difference was found in shoot growth of the plants among shapes. However, at the third leaf stage, the plants grown in round and triangular cells had smaller roots with lower N, K and P contents than did those in pentagonal and square ones. Root respiratory activity and photosynthetic rate were unaffected by cell shape. At the fourth leaf stage, shoot grew slower in round cells, had a lower K and P contents, and a reduced photosynthetic rate compared to others. No significant difference was observed in plant growth between pentagonal and square cells at any growth stage. The growing medium in round cells had the lowest water-holding capacity, followed by pentagonal, square, and triangular ones.