Abstract
Cultivation of yacon (Polymnia sonchifolia) has gradually been spreading in Japan. We experimented on the effect of planting methods on the growth and yield of yacon by using a Light-colored Andosol. Two experimental plots were made: plot A in which seed tubers were placed directly into the field soil and plot B in which seedlings were transplanted after raising them.
The results were as follows.
1) Growth of yacon in plot A was faster than that in plot B in the initial stage. But, at harvest, the difference of top fresh weights and dry weights were not significant in both plots.
2) Since the yield of yacon tuber in plot A (46.8t/ha) was much higher than that in plot B (27.8/ha), the method placing seed tubers directly into the field soil will be more suitable to obtain maximum yield.
3) Since more time was used for weed control in plot A than in plot B, investigation of the weeding system will be necessary.
