Hi Tui, our potatoes have brown lines across the middle when cut in half. What can we do to prevent this in the future? And what causes this?

Hi Valerie, there are several reasons for this to happen. Usually it is a sign that the crop has been stressed at some stage, it is likely to be too hot and constant heat, with no overnight cooling of temperature can cause this; infrequent or irregular watering or insufficient feeding throughout the growing season. There is an insect called the Tomato/Potato psyllid that can cause ‘Zebra Chip’ which causes brown flecking throughout the potato. It is a small sap sucking insect that carries a bacteria that affects plants of the Solanaceae family, especially tomatoes and potatoes. You would know if it was psyllid because your plants would be showing signs and collapsing. If you can eliminate psyllid, and you think the flecking is caused by environmental stress, they should still be okay to eat as long as they firm and not soft. If they are soft, discard.