Hi Tui, our new potatoes have brown wart-like marks on them, what is it?

Hi Debbie, photos are always good to help positively identify what the problem might be. It sounds like Scab iis affecting your new potatoes, this is a soil-borne disease that does not affect the foliage but affects the tubers, damage can be superficial or pitted into the flesh of the potato, some potato varieties have a natural resistance to Scab. Warm dry summers affect the incidence of Scab, it makes the tubers look unsightly but doesn't affect the yield of the crop, depending how deeply the tubers are pitted, you can still cook with potatoes affected with Scab, peel the skins before cooking. To help prevent Scab affecting future crops, rotate crops, avoid growing potatoes in the same spot if Scab is present. Scab is affected by soil pH, it does not like acid soils, add a small amount of Flowers of Sulphur to the soil to lower the soil pH. The Tui Team.