The trial was carried out on a farm located at 46°04' N, 14°31' E in Slovenia. The soil texture was classified as silt loam (SL) including 20% of clay, 15% of course silt, 40% of fine silt, and 25% of sand. Three different potato cultivators/ridgers were used in the trial. Based on random blocks with five replications, it was conducted in three consecutive years: 2002, 2003 and 2004. Each block, 10 m in length and with a one-metre side strip, featured a random allocation of three potato cultivators/ridgers. Each plot with an area of 24 m2 was 3 m wide and included 4 rows of potatoes at a 75 cm IRW. All measurements were carried out in the inner two rows. All data on primary soil treatment,basic fertilization and spraying are shown in Table 1. Before the process of planting,planting holes were made with a 4-furrow machine. Potatoes were manually planted at a distance of 29.6 cm, creating an exact tuber density of 45,000/ha, and covered with soil by ridge discs. Seed tuber tops remained level with the surface. Ridging was conducted immediately before the potato emergence (i.e., approximately 1 month after the planting).