Concentration of nutrient solution in the hydroponic production of potato minitubers

The effect of the nutrient solution concentration on potato plant growth and minituber yield were determined in a sand closed hydroponic system. Minitubers and micropropagated plantlets of the cv 'Macaca' were used. Treatments were five nutrient solution concentrations at electrical conductivities (EC) of 1.0 (T1), 2.2 (T2), 3.4 (T3), 4.7 (T4) and 5.8dS m(-1) (T5). The split plot randomised experimental design was used with three replications. Plants from minitubers produced higher fresh and mean weight of minitubers, shoot dry mass and leaf area index than the micropropagated ones. However, higher dry mass of minitubers was found with micropropagated plantlets compared to minitubers. The concentration of the nutrient solution did not affect minituber number. Increasing the nutrient solution concentration decreased total and minituber dry mass production of micropropagated plantlets and plant growth and minituber production of minituber-originated plants. Low concentration of nutrient solution at an EC of about 1.0dS m(-1) can be used in the hydroponic production of potato minitubers of both micropropagated and minituber-originated plants.