The main function of Boron relate to cell wall strengths & development, cell division, fruit & seed development, sugar translocation & hormone synthesis.
The Boron requirement at flowering & seed set may be higher than that needed for vegetative growth.
Boron (B) has a significant effect in pollen germination & pollen tube growth. The viability of pollen grains also decreases when B is deficient.
Boron (B) deficiency increases the drop of buds & flowers, resulting in significant reduction in seed & fruit set & also in the quality of fruits, seeds, nuts etc.