Black Root of Beets

a disease of the sprouts and seedlings of beets caused chiefly by the fungi Pythium de Baryanum, Aphanomyces cochlioides, Phoma betae, Rhizoctonia Aderholdii, and various species of Fusarium, as well as by bacteria that live in the soil and enter the seeds. The disease is found wherever beets are cultivated.

Small yellowish brown spots and stripes that frequently merge, forming a ringlike constriction, appear on the rootlet and hypocotyl of infected plants. The disease is more likely to develop if the beets are grown on poorly structured, overly moist, and acid soils, receiving insufficient warmth and nutrients and if low quality seeds are sown. Black root of beets often kills many or all of the seedlings; those beets that survive the disease usually lag in growth and development, and the harvest is reduced by 10–40 percent. Control measures include agrotechnical methods that improve the growth and development of the plants and treatment of the seeds with fungicides.