INFLUENCE OF PLUG CELL SIZE FOR ROOT VIGOR AND SEEDLING QUALITY ON GRAFT WATERMELON SEEDLING

Using three kinds of plug tray to grow watermelon seedling, grafted in root cutting. The results showed no significant difference among treatments when the seedling age is 20 days after grafting. Plug cell size at 78.4 cm³ - 82.9 cm³ restrained seedling growth and root vigor when the seedling age was at 25days after grafting. Seedling stem height, root dry weight, leaf area index and root vigor were primarily functions of the cell size. We suggest the best seedling age is between 20 and 25 days, and a cell size of 78.4 cm³ - 82.9 cm³. Ultimately a Seedling age of 30 days with a cell size of 131.6 cm³ can be permitted.