Boron deficiency in palm trees can cause leaves to appear small and crumpled. Other symptoms are sharp bends in the trunk with horizontal growth and bud necrosis or death.
Prevention and Treatment of Boron Deficiency
Boron can also be toxic even in small amounts, so generally fertilizers for palms should contain only very small amounts of boron. Sodium borates, boric acid, borax or Solubar can be applied at 2 to 4 ounces per tree.