Soilless production of potato minitubers using a hydroponic technique

Summary

Potato minituber production is a classic way to multiply or acclimatize in vitro material before its use in the open field. This production is generally performed in a substrate of vegetable origin (based on peat) but it involves the risk of an infection by different pathogens present in the substrate, such asStreptomyces scabies (common scab),Spongospora subterranea (powdery scab), orErwinia spp. (bacterial soft rot). Another drawback associated with this system of production is its relatively high cost due to the initial cost of the in vitro material and the low multiplication rates.

To solve these two problems, the Research Unit of Libramont (CRAGx, Libramont, Belgium) is developing a soilless production technique using clay balls as substrate, a recycled and disinfected nutritive solution as source of nutrients, and microtubers as in vitro starting material. With this technique (depending on variety), we have shown that a multiplication rate of 8 to 13 can be obtained, giving 470 to 760 minitubers per m² instead of a multiplication rate of 4 to 8 as observed in the controls (230 to 470 minitubers per m²). Multiplication rate may be improved even more with an adjustment of the composition of the nutrient solution. The quality of microtubers produced is excellent: no infections were observed and the physiological behaviour of these tubers is not different from the ones produced in the open field.