Evaluation of Rooting Ability in Cabbage Plug Seedlings by Drag Resistance (Resistance to Uprooting)

Abstract

The drag resistance (resistance to uprooting) of seedlings after transplanting was measured with a pull gauge for evaluating the rooting ability of cabbage plug seedlings. A high coefficient of correlation, r, exists between the increase in root weight and the drag resistance of seedlings made within eight days of transplanting. The same tendency was observed between the quantity of new roots growing out from rootball. The drag resistance of seedlings decreased conspicuously when plug seedlings were placed in the dark after transplanting. The drag resistance was not affected by uprooting speed of the seedlings. By subtracting the drag resistance of seedlings just after transplanting from the experimental values, the effect of particle size in the soil media could be excluded. Differences in rooting ability could be measured more accurately by laying a plastic sheet under the rootball at the transplanting time. As a result of this study, rooting ability of plug seedlings could be evaluated by measuring drag resistance of seedlings within eight days after transplanting.