A new way of growing seed potato crops could increase tuber production tenfold over current systems.

The Finnish Seed Potato Centre has spent the past two-and-a-half years developing an aeroponic method of growing seed potatoes on a commercial scale.

As managing director Lauri Juola explained, the aeroponic system is based on having the roots of the potato plant dangling in the air within a dark, closed chamber, while the stem and leaves are exposed to light above. “The roots are sprayed with a nutrient-rich solution at carefully defined intervals, with the composition tailored for each species and growth stage.”

A significant amount of development work was needed to develop the special aeroponic equipment, he said. Spraying of the nutrient-rich solution is fully automated and it also controls the lighting environment.

Seed potato production is a long process, starting with the production of mini-tubers in greenhouses. The aeroponic growing system will be applied to this stage, explained Mr Juola.

Production starts with the micro-propagation of tested disease-free and genetically pure plants in sterile laboratory conditions. The seedlings are then planted in peat beds within a greenhouse. However, the aeroponic method does not use peat or any other growing medium. Resulting mini-tubers are then propagated in fields.

With the traditional peat method, each plant generates four to eight mini-tubers after a three to four month growing period, after which, they are harvested. But as production manager Jukka-Pekka Palohuhta pointed out, with the aeroponic system, tubers are continually harvested, which stimulates plants to keep producing new tubers. The result is that it increased mini-tuber production up to 100 a plant.

Field trials on aeroponic tubers indicated their quality and vitality are no lower than tubers from the conventional system. The number of potato eyes for each tuber is greater, which suggests the propagation potential of aeroponically cultivated tubers, during the following stages, will be better than traditional ones, he said.

“In addition, unit production costs will decrease significantly, as the greenhouses can produce a significantly greater number of tubers,” Mr Palohuhta concluded.