Already with slight B deficiency, the petioles are brittle and break off suddenly, which leads to lower yield. Fruits are not marketable because of their chapped surface. Roots are short and with thickened necrotic tips. With severe boron deficiency, the growing points of main shoot and laterals die and the crop is lost. The younger leaves remain small, are curled inwards and deformed. They show chlorotic spots between the veins which are yellow to orange and the veins themselves can become yellow or purple. The older leaves appear yellowish green.
Made worse by
Sandy soils. Alkaline soils. Soils low in organic matter. High levels of nitrogen. High levels of calcium. Cold wet weather. Periods of drought.
Meristem growth. Pollen germination. Carbohydrate metabolism. Synthesis of nucleic acids. Calcium transfer. Enhanced sugar degree. Higher sugar production.
Boron deficiency. Boron deficiency may be caused by overliming the soil. This leads to immobilization of the soil boron which cannot be taken up by the plant then. Also with severe Calcium deficiency the growing point dies and the younger leaves are deformed, but in this case leaf tips and margins wither and the fruits show typical blossom-end rot.