What causes hollow heart in potatoes?

[Disease diagnosis] It occurs more often in larger tubers. At first, the central tissue of the tuber becomes water-soaked or translucent, and some centers develop brown necrotic spots. In the later stage, a cavity forms near the center of the tuber. Most cavities are lens-shaped or star-shaped, with edges that are mostly angular; some tubers develop cracks inside; and some hollow shapes are spherical or irregular. The inner wall of the cavity is white, light brown to straw yellow, forming an incomplete suberized layer. Usually, the cavity expands as the tuber grows. Sometimes mold can be seen in the hollow area, but rot rarely results from it.

[Cause] This is a physiological disease. It is often caused by overly rapid tuber development and uneven tissue expansion. There are several reasons for this phenomenon: First, when the plant population structure is unreasonable, some tubers grow too vigorously and their internal and external tissues develop unevenly, often resulting in severe hollow heart; second, the influence of potassium deficiency, and potassium content below the critical level may be one of the factors making plants susceptible to hollow heart; third, when water supply is unreasonable, with water deficiency in the early stage followed by a sudden shift to environmental conditions suitable for rapid growth, hollow heart in tubers can also be induced. Under these conditions, hollow heart is most severe during the growing season or when cultivation management favors rapid tuber enlargement. Clearly, rapidly growing tubers have a higher rate of hollow heart than slower-growing ones. Conversely, in cultivation, reducing the distance between plants, increasing potassium fertilizer application, and reasonable fertilizer and water management can reduce the incidence of hollow heart. The incidence rate differs among varieties.

[Control measures] (1) Plant resistant varieties with a low incidence rate. (2) Maintain reasonable density, avoid missing plants, adjust the spacing between plants, and increase competition among plants, thereby preventing excessive growth and enlargement of tubers and reducing the incidence of hollow heart. (3) Strengthen cultivation management, ensure water supply for plant growth, avoid uneven drought and waterlogging, and promote a balanced and consistent development rate of tubers. (4) Increase potassium fertilizer application to reduce the incidence of hollow heart.