Sweet potato

Boron deficiency in sweet potatoes

Brown necrotic areas are found in the flesh of the root, particularly near the cambium around the periphery of the root when sweet potato is boron deficient. The flesh and roots are misshapen and the skin is rough and leathery in texture. Severely affected roots show surface cankers and splits covered with a hardened and blackened exudate. Boron deficiency symptoms usually appear in the latter part of the season. The terminal growth of the vines is restricted and the internodes are shortened.

As the deficiency becomes more severe, the petioles are curled and twisted, and the growing points may die. Premature abscission of leaves also occurs.

Typical recommended ranges for boron boradcast soil application for sweet potatoes is 0.5-1 lbs of B/acre. Normal plant analysis levels for the best quality and marketability have leaf boron levels in the 20-40 ppm range.*

*Always consult local crop advisors to check the proper dose rates. Rates of boron fertilization should be based on yield goals along with soil tests and/or plant tissue analyses.