Role in plants
Boron is essential for cell wall structure, membrane function, sugar transport, and pollen tube growth (fruit set). It is poorly mobile in many crops.
Deficiency symptoms
- Brittle, distorted young leaves
- Cracked stems/petioles
- Poor pollination and fruit set
- Hollow or corky tissues in some crops
- Death of growing points in severe cases
Toxicity symptoms
- Leaf tip and margin burn
- Yellowing progressing to necrosis
- Often appears first on older leaves
Natural sources
- Parent material and soil solution
- Some irrigation waters (variable)
Fertiliser sources
- Boric acid
- Sodium borate / Solubor-type products
Plant uptake forms
- H3BO3 (boric acid)
- Borate species depending on pH