Coiled sprouts

Description

When actively sprouting tubers are planted in a cold soil, as is largely the case with early potatoes, there may be non- or late-emergence due to abnormal growth of the sprouts (coiled sprouts), which may even have difficulty getting though the crust of a soil compacted by heavy rainfall. These conditions also favour attacks of black scurf  on the sprouts.

Coiled sprouts are also encouraged by an over-incubation of the seed tubers.

This phenomenon is often accompanied by swellings in the underground part of the stems revealing hollowed-out pith and sometimes longitudinal cracks (photo 1).

Control measures

• Seed potatoes should be kept in a cold room until pre-sprouting so as to prevent too rapid an incubation.

• In the pre-sprouting room, growth should be held back by homogeneous lighting of the seed potatoes from the “white dot” stage.

• Planting should not be done too early in a cold soil.