University of Florida

Deficiency of Boron

There is probably a deficiency of Boron. Raised corky areas on main veins on the underside of young leaves usually occur before other symptoms on Boron deficient plants. Leaves appear leathery, are small and possibly cupped, wrinkled and thickened. Leaf chlorosis and yellowing may be evident in some species. Other affected parts may become stiff, brittle, cracked and shortened. Terminal meristems stop cell division causing tip dieback. Lateral buds develop to 1 to 2 inch shoots with dwarfed and twisted leaves. Flower petals lose color and fail to form fruit and seeds.

Plant is a dicot (broadleaf tree or shrub)

  • Symptoms are exhibited by the new leaves or recently mature leaves
    • Leaves are not in rosettes
      • Leaves are usually not chlorotic
        • Leaves not elongated or narrow
          • Tip die back
            • Leaves have corky veins, leaves are leathery, leaves are cupped