Comparison of growth and yield among field-grown potato plants from microtubers of different weight classes

Abstract

Although the potato microtuber production procedure is well know, there are few studies about the effect of microtuber size on the growth and yield of field-grown potato plants. This study compared the shoot and tuber growth of field-grown potato plants from microtubers of different weight classes. The experiment was carried out at the Hokkaido University, Sapporo, Japan, using microtubers of four weight classes (SS: 0.3-0.5 g; S: 0.5-1.0 g; M: 1.0-3.0 g and L: 3.0-5.0 g) of a late maturity cultivar Norin 1. The microtubers were planted by hand on the beginning of May, 1998 in a completely randomized block design with three replications. Plants were sampled at four growth stage and at harvest. No difference in the days from planting to emergence among the microtuber classes was observed, but, the percentage of emergence and days from emergence to flowering was greater in the heavier microtubers. At the initial growth stage, root and tuber dry weight and leaf area index were smaller for the lighter microtuber class, but as the growing season advanced, these differences disappeared. No difference in the number of tubers, fresh and dry tuber yields was observed among the microtuber classes, suggesting that microtubers could be used as seed tubers in countries where is difficult to produce healthy tubers in the field.