What causes the black marks in pototoes.When I peel some potatoes the have black marks in them. I cut these out and the cook the potatoesCould you please tell me what causes the black marks?
Mineral deficiencies can be involved too, such as potash deficiency, if nitrogen is high. Boron deficiency may also be a factor.
Try to handle carefully, use certified seed potatoes and apply a general fertilizer and perhaps a spray on a liquid feed during growth to deal with minor deficiencies