Effects of Planting Date and Field Type outweighed the Effect of Seed Origin on Ware Potato Yield

Potato yields in the Netherlands are highly variable. Although variability in yield has previously been attributed to several crop management factors, part of the variability remains unexplained. It is hypothesized that part of this unexplained yield variability is influenced by seed potato origin, encompassing where and under what conditions seed potatoes have been cultivated. In this study, we investigated the effect of seed potato origin on crop characteristics and tuber yield in interaction with and in comparison to planting date and field type in a two-year on-farm experiment on a large-scale potato farm. We evaluated three different seed potato origins of the variety Fontane, three different planting dates (early, intermediate, late), and two different field types (wet rainfed and dry irrigated). Origin significantly affected the number of stems per plant and the number of tubers per stem in both years. This resulted in a significant effect of origin on the number of tubers per plant in the first year. In that year, the origin with the lowest number of tubers per plant also produced the highest yield of tubers larger than 50 mm. Despite these (small) effects of seed potato origin on crop characteristics, origin did not significantly affect gross and marketable yield. Moreover, there was no interaction between origin and planting date and/or field type. However, planting date and field type had a significant effect on yield. Ware potato yield in the wet rainfed field was up to 17 t ha⁻¹ higher than in the dry irrigated field, and late planting resulted in a yield reduction of up to 10 t ha⁻¹. We conclude that for maximizing ware potato yield of the variety Fontane in the Netherlands, the effects of planting date and field type outweighed the effects of seed tuber origin.