Potato minituber production through hydropony: assessment of a system combining the NFT and Gravel Culture techniques for two types of nutrient solutions. The potato minituber production is the classical intermediate stage enabling field use of potato materials with an in vitro origin. This production of minitubers may be achieved through various techniques. Most often however they are based upon bedding vitroplantlets or vitroplantlets cuttings in an organic substratum which is disinfected or not. The soilless culture of plants stemming from vitrotubers to produce minitubers with a superior health quality was tested within a hydroponic system. Two types of nutrient solutions were compared: a nitrogen rich one (NPK, mg/l, 180-40-300) and a phosphorus rich one (NPK, mg/l, 60-150-300). In order to initiate the cultures, presprouting microtubers of several varieties (Bintje, Kennebec, Spunta, Saturna, Desiree and Gasore) were used. Multiplication rates ranged between 13.2 (Saturna) and 3.8 (Kennebec) minitubers with a grade higher than 10 mm (more than 1.5 g). As the selected density of the plants was 59 plants per square metre, the yield per square metre varied from 224 to 779 minitubers with a grade higher than 10 mm. The obtained number of minitubers depended especially on the variety. The phosphorus enrichment of the nutrient solution induced an increased number of minitubers produced with a grade higher than 15 mm (more than 5 g). The health state of the produced tubers was excellent.