2021 Volume 56 Issue 2 Pages 103-109
We developed a tuber planter that planted and pushed down small sweetpotato tubers by modifying a semi-automatic vegetable transplanter. The mechanism used to plant and push down the tubers follows. The beak-shaped hopper, containing small sweetpotato tubers, descended and penetrated the ridge. When the beak-shaped hopper opened, the plastic plate in the hopper pushed down and released a tuber. We investigated the effect of planting small sweetpotato tubers using this planter on the yield, stand establishment, bird damage, planting depth, and planting angle. The variation of planting angle and the variation of planting depth were lower for the tuber planter than the vegetable transplanter. The tuber planter was able to plant tubers in a nearly horizontal state. The percentage of bird damage tended to decrease as the planting depth increased. The germination percentage （obtained by dividing the number of germinations by the total number of tubers planted minus the number of bird damage） tended to increase as the average or median of planting depth decreased. The percentage of planted tubers enlargememt tended to increase as the planting depth decreased. The yield per unit area in 2018 was the same for the tuber planter as for hand planting, and greater than for the vegetable planter; however, in 2019 it was the same for the three planting methods. The working hours of the tuber planter was about 1.9 hours per 10 ares, which was decreased about 14 hours per 10 ares compared to hand transplanting.
