2021 Volume 56 Issue 1 Pages 39-48
Our previous study showed greater yields of potato tubers weighing 60 g or more with staggered planting than with conventional planting. In staggered planting, seed potatoes were planted in a staggered pattern at a distance of 150-mm. The soil was then immediately ridged using a commercial rotary hiller at 1500-mm intervals, which included four seed rows in two ridges. On the other hand, in conventional planting, the soil was ridged at 750-mm intervals, which included one seed row per ridge. However, with the previous staggered planting method, in which planting and ridging were performed separately, the tines of the hiller tended to nudge the seed potatoes and bring them up to the ridge surface, causing them to green. We therefore modified the potato planter that had been developed for staggered planting in a previous study to perform simultaneous ridging and planting, which included two seed rows per ridge at 750-mm intervals. We then compared the impact of staggered planting using the new planting method on potato quality with that of conventional planting and the previous staggered planting method in 2016 and 2017. With the previous staggered planting method, the greening rate of potatoes was significantly higher with staggered planting than with conventional planting in 2016. On the other hand, with the new staggered planting method, due to ridges follows the planting, no significant difference was found in the greening rate between the new staggered planting and conventional planting in either 2016 or 2017. In 2016, the weight of individual potato tubers and the potato yield as tubers weighing over 60 g were both significantly greater with staggered planting than with conventional planting, regardless of the planting method. In 2017, however, there were no differences in the weight of individual potato tubers or the potato yield as tubers weighing over 60 g between staggered and conventional planting.
