Boron Deficiency in Broccoli
The most common symptom of boron deficiency in broccoli in the field is poor and discolored bud formation, which frequently renders the crop unsuitable for marketing. The pith is liable to develop water-soaked areas, and to become necrotic and ultimately hollow.
An early symptom in young seedlings is the rolling and down-curling of the newest leaves, which are abnormally small, brittle, and deformed. Sometimes leaves have a much enlarged midrib and little lamina. If broccoli is not in bud when the deficiency becomes established, the stem stops growing, giving a flat-topped plant with many side shoots.
Typical recommended ranges for boron boradcast soil application for broccoli is 2-3 lbs of B/acre. Normal plant analysis levels for the best quality and marketability have leaf boron levels in the 25-50 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.