The mineral profile in organically and conventionally grown "early" crop potato tubers

In several regions in the Mediterranean Basin potatoes are grown during the winter-spring cycle, which involves an intensive application of farming inputs. Consequently, the possible health risks and the environmental impact of conventional cropping have fuelled a major expansion of the organic farming sector. The "early" crop potato can be profitably grown organically, but few data have been published to date regarding the product quality. This study was focused on the evaluation of the mineral profile of three "early" potato cultivars (Arinda, Ditta, Nicola) both organically and conventionally produced over two consecutive seasons. The organically grown tubers contained more phosphorus (2.8 vs. 2.3gkg-1 of dry matter) and a comparable quantity of both magnesium and copper (on average 250 and 2.6mgkg-1 of dry matter, respectively) than the conventionally grown ones. However, potassium, calcium, iron, sodium and manganese were all less well represented in organically grown tubers. More phosphorus, magnesium and iron was accumulated by cv. Arinda under organic cultivation, while conventionally grown tubers of cvs. Ditta and Nicola contained more magnesium (270mgkg-1 of dry matter, on average). Organic cultivation can therefore generate tubers with a distinct spectrum of minerals compared to that of conventionally grown tubers. However, both cultivar choice and weather conditions are also important determinants of the mineral profile of the "early" crop potato tuber.