Effect of cultivar type and soil properties on cadmium uptake in potatoes

Potatoes are a staple food in New Zealand and an important source of dietary cadmium (Cd), although there is little information on the soil and plant factors that affect Cd uptake. We measured Cd uptake in 10 commercial potato cultivars grown in field sites across New Zealand and assessed the soil factors that affect Cd uptake. The Cd concentrations in potatoes ranged from 0.001 to 0.113 mg kg-1 FW, although overall concentrations were lower than the maximum limit of 0.1 mg kg-1 FW. There were significant differences (two-fold) in Cd uptake between potato cultivars, although no significant relationships were found between soil properties and Cd uptake. Management of Cd in potatoes is likely to be most effective avoiding growing high-Cd-accumulating cultivars in Cd soils. Further studies could determine if other management factors such as irrigation or type and rates of fertiliser affect Cd uptake in potatoes.