Boron Foliar Fertilizer
Boron is essential for correct meristem (growing points of roots and shoots) growth, carbohydrate metabolism, synthesis of nucleic acids and pollination. The solubility of B is pH dependent and deficiency problems are more likely on alkaline soils (pH>7.0). Coarse or sandy soils, and those subject to excessive leaching, can also lead to B deficiency. Boron also becomes less available during long periods of drought. Application of boron after observing symptoms is usually too late to prevent the problem.
Crops most affected by Boron deficiency
- Brassicas. In particular, Cauliflower, Swede and Turnip are susceptible to Boron deficiency. Deficiency can cause 'Brown Heart' - when soft brown centres develop. Cauliflower curds may be stunted or turn brown.
- In Carrots Boron deficiency shows up as 'Five o'clock Shadow' - a discolouring of the carrot just below the skin. The new leaves can also look pale and become necrotic. Germination and growth are stunted as well.
- In Beetroot it causes canker and dark spots inside the Beetroots. Young leaves can be distorted.
- Celery is sensitive to B deficiency which causes the disorder known as 'Cat Claw' - when the epidermis splits along the
Boron Deficiency in Plants
- Cell division does not proceed normally at the growing points - tissue becomes distorted and eventually dies. This can lead to development of side shoots and a bushy appearance to the plant. New leaves are small and misshapen
- Damage to cell walls is responsible for the brown flecks, stripes and marks in sugar beet ('heartrot'), swedes ('brown heart'), carrots ('five o'clock shadow') and celery (stripes along stems). Beetrot can also develop warty growths.
- The stems of boron deficient plants may become brittle, have corky areas of tissue and develop obvious cracks. Branches can be hollow, split and ooze sap.
- Fruit is often small, misshapen and cracked. The fruit of apples and pears may have corky areas on the skin and brown spongy lesions in the flesh.
- Root crops are often misshapen and develop a hollow core.
- Diseases that cause rotting are more common in boron deficient crops because of the damage to the cuticle caused by the disorder.
- Deficiency also affects pollination and seed set.
EU-Fertilizer Borethanolamin 11 11% B (150gr/L)
Use and application
Boron is best applied to the soil at the beginning of the season at double the dose, then again when there is enough leaf to absorb the feed. In severe cases of deficiency another dose can be applied later on in the season.
- Dilute 50ml per 5-8litre for smaller plots. 50ml is enough for 250m2 as a foliar spray and 125m2 on the soil.
- 1 to 3 litres per hectare as a foliar feed ususally twice per season.
- 4 to 8 litres per hectare as a fertilizer on the soil
- It's important not to add too much Boron since in high concentrations it can be toxic to plants.
Appr. for use in Org. Agr. EG-OEKO-VO