Stress and crowding as causes of potato defects
A well-distributed crop of potatoes is shown developing from plant shown in first photo to right. The soil has been removed by air blast and tubers left in natural position. Note that stolons are long enough to allow space for smooth development. Rhizoctonia often strikes late in the season, as shown in middle photo. These tubers reached about 3 oz in size by mid-August. At this time, rhizoctonia completely severed the stolons at the locations shown beneath the white pieces of paper. From August until harvest tops remained green but tuber growth remained as seen. In third photo to right, a young plant shows well-developed stolons and a good first set of potato tubers. Few pressure defects will develop in such a hill.