Basal part of young leaves and internal tissues of organs may become necrotic . One of the earliest symptoms is failure of the root tips to elongate normally. Terminal shoot meristems also die giving rise to a witch's broom. Young leaves of terminal buds become light green then necrotic and stem finally dies back at terminal bud. Rust colored cracks and corking occur on young stems, petioles, and flower stalks.
Necrosis occurs at tip and margin of leaves causing a definite hook at leaf tip .
Growing point dies. Stem structure is weak and peduncle collapse or shoot topple may occur. Roots are stunted. Premature shedding of fruit and buds is common. However, when boron is deficient, the breakdown occurs at the bases of the youngest leaves.