Potato tuber greening risk is associated with tuber nitrogen content

Tuber greening is one of the major causes of quality loss in the potato industry, however, the impact of nitrogen in-field fertilisation on this visual defect remains unknown. Two field experiments, one in Tasmania with final N treatment rates of 40, 100 and 190 kg N ha^-1 for Nicola and 35, 95 and 185 Kg N ha^-1 for Maranca, and another in South Australia with N rates of 100, 200 and 300 kg ha^-1 for Maranca, showed a positive linear relationship (R² = 0.99, 0.86 and 0.90, respectively) between tuber N content and tuber greening, as determined by chlorophyll content. However, increased N fertilisation rates did not directly translate to increased tuber N content, with responses appearing to be variety specific. We conclude that tuber N content is a risk factor associated with tuber greening, but the manipulation of tuber N content through N fertilisation rate is not straightforward and may depend on variety and location.