Functions and deficiency symptoms of Boron

Functions and deficiency symptoms of Boron

  • Boron is present especially at the growing points and in the conducting tissue. This element being a non metal doesn’t appear to be a part of any enzyme system. Plants absorb B as H3BO3-, B4O72-, H2BO3-, and HBO2-3 & BO32-. It is immobile element in plants.


      1. Essential for cell division in the meristematic tissues.
      2. Involved in proper pollination, pollen formation, pollen tube growth/ flowering and fruit or seed set.
      3. Important role in the fertilizing process of plants and during blossom period its requirement is high.
      4. It influences carbohydrates and N-metabolism and also Ca.
      5. Translocation of sugars through cellular membranes and prevents the polymerization of sugars.
      6. It enhances rooting of cutting through oxidation process.
      7. It has role in hormone movement and action.
      8. It gives resistance for pest and disease infection, e.g.: virus, fungi & insects.
      9. Role in water relations i.e., prevents hydration of root tips & thus strengthens the plant roots
      10. Acts as a regulator of potassium/calcium ratio in the plant. Solubility & mobility of Ca increases.


      1. Young leaves may be deformed, appear like a “rosette”, cracking and cork formation in stems, stalks and fruits, thickening of stems and leaves, reduced buds, flowers and seed production. 2. Premature seed or fruit drop.
      3. ‘Hen and Chicken disease’ in grapes bunches i.e. fruits of vine with small & long berries.
      4. Deformed fruits of papaya tree.
      5. Vine plant with thickened internodes. Poor fructification and development of the berries. In mango, leaves become pale green distorted & brittle leaves.
      6. Browning or hollow stem of cauliflower.
      7. Heart rot disease’ in fruits of the sweet melon (Cucumis melo), sugar beet & marigold.
      8. Interruption in cell wall formation and differentiation and then necrosis.
      9. Flowers wilt, die and persist on the tree. This phenomenon is called “Blossom Blast”.
      10. Tissue break down and preventing sugar and starch accumulation in the leaves.
      11. Excessive formation and accumulation of phenolics.
      12. Bitter orange fruits with thickened peels or rinds & blackish discoloration.
      B Toxcity- yellowing of the leaf tip and leaf margin which spreads towards the midrib leaves become scorched and may drop early.

  • (Youngest leaves light green, mottled, with uneven edges and asymmetric shape; new leaves with dead spots or tips).
  • ‘Hen and Chicken disease’ in grapes bunches i.e. fruits of vine with small & long berries.
  • Deformed fruits of papaya tree due to B deficiency.


Last modified: Wednesday, 7 December 2011, 5:06 AM