Effect of Potato Microtuber Size on the Growth and Yield Performance of Field Grown Plants

Abstract

To examine the effect of the size of the potato microtuber (MT) produced in vitro on the posterior field performance, we examined the growth and yield of the late maturity cultivar Norin 1 using four sizes of MT: 0.3–0.5 g, 0.5–1 g, 1–3 g and 3–5 g, and conventional seed tubers (CT) (approximately 50 g). The experiment was conducted at Hokkaido University, Sapporo Japan in 1998 and 1999. The tubers were planted in May of each year, in a randomized block design with three replications. Plants from MT lighter than 0.5 g showed a slower initial leaf and tuber growth than heavier MT, but around the full flowering stage there was no significant difference with the MT size in leaf or tuber growth. CT plants showed higher initial leaf and tuber growth compared with MT plants, especially in 1999. No differences in growing period, number of tubers, and tuber fresh and dry yield were observed with the MT size. However, in 1999, the growing period was longer and tuber fresh and dry yields at harvest were higher in CT plants. MT of all sizes used in the study can be used for direct field planting, but more studies are needed to increase the yield stability of MT plants.