キャベツの苗取り作業の能率化に関する研究

Abstract

In Japan transplanting machines are seldom used commercially yet, but have been tested on their usefulness for several crops at several experiment stations. In considering the transplanting work, however, attention has never been paid so much to the labor requirement of removing plants from the seedbed by hand as to the efficiency of the transplanting machine itself.This investigation was made to find some efficient operations for saving time in removing cabbage plants from the seedbed.Labor required for removing plants from the seedbed was nearly comparable to that for transplanting which was carried out with a one-row hand-fed machine operated by a gang of three. This indicates that time-saving operations are needed for removing plants as well as for transplanting in order to increase output of workers.Time study on removing plants from the seedbed showed that large saving of time was possible if plants could be lifted up without sorting out inadequate ones, which was indispensable for drilled plants. Pulling plants by holding the stem was also an efficient way compared with lifting out them by grasping the underground part. By the former way, however, the plants lost nearly all fine roots, so that it was feared that their survival rate might be low after setting out. To loose the soil between rows made the lifting operation somewhat easier.An operation of separating entangled plants as occurred on drilled plants, which had been hitherto considered unavoidable, was found omissible in view of maintaining the accuracy of planting at the standard speed of the transplanting machine. The elimination of this operation may contribute to some extent to overall saving of time.The drilled seedlings, transplanted into rectangular arrangement in the seedbed, grew into more uniform plants and could be lifted up from the seedbed with less time required, as compared with those being left untransplanted. This reduction of time was resulted from the easier operation to sort out unsuitable plants, as each plant grew uniformly and with reasonable spacing.Precision planting of seeds produced more uniform plants than the rectangular transplanting of drilled seedlings did, so it was also expected to reduce time for lifting up the plants and was regarded as being worthy of consideration.On planting seed precisely in the seedbed, density and distance of seeds were investigated in relation to the growth and uniformity of plants, with the distance between rows being fixed at 10cm in view of practical standpoint. To plant seeds at 40cm2 per seed was better than at 20 or 30cm2 per seed, and one or two seeds per hill better than three seeds per hill, in that plants grew more uniformly and a higher rate of suitable plants was obtained for mechanical transplanting.