Boron Deficiency in Brussels Sprouts
The first signs of boron deficiency in Brussels sprouts are swellings on the stem and petioles, which later become suberized. The leaves are curled and rolled, and premature leaf fall of the older leaves may take place. The veins are frequently wrinkled. The growing point may die, followed by the development of two axillary buds leading to twinning of stems. If the deficiency becomes established before the sprouts are formed, very few develop. If the sprouts have started forming, they remain small, fail to heart, and have a loose appearance. The stem pith may be hollow and discolored.
Typical recommended ranges for boron boradcast soil application for Brussels sprouts 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.