Deficiencies can be corrected readily by foli2ar spraying with manganese sulphate. Boron leaches readily in sandy soils, so that where boron is deficient, soil applications should be made before planting and while the crop is growing. A symptom often attributed to boron is browning below the skin known as '5 o'clock shadow'. Oxidative browning of carrots resulting from bruising during the washing process is often confused with this symptom. Boron levels of 50 to 60 ppm have been recorded in healthy whole tops at 12 weeks.
New leaves are yellow, small and distorted, giving the tops a rosette-like appearance.
Deficiency symptoms are seen most often in mid-summer. Tissue levels as low as 25 ppm have been recorded in healthy whole tops. Foliar sprays will correct a deficiency. Fertiliser programs Fertiliser programs suggested for carrots on new land, or where crop residues are poor, are shown in Table 2 for three cropping situations. The nutrients needed by a crop over its whole life are shown in Table 3.