A continuous supply of nitrogen, phosphate and potassium is essential throughout the season to obtain high yields and good quality. Nitrogen fertilising is important and 300 to 400 kg/ha of limestone, ammonium nitrate or ammonium sulphate, depending on soil analyses, are applied in 2 or 3 dressings during the growing season. About 150 kg/ha of nitrogen is usually applied at planting time and the rest when the plants are about 10 to 15 cm high. A total of 500 to 600 kg/ha of superphosphate and 200 to 300 kg/ha of potassium chloride are applied just before sowing. Alternatively, a fertiliser mixture of
2:3:2 (22) at 1000 to 1200 kg/ha may be applied. It should be noted that these are general recommendations and actual amounts of fertilizers should be based on soil analyses. Soils heavily fertilised with coarse compost and kraal manure encourage the formation of side roots, making the crop unattractive.
The soil should never be allowed to become dry and it should be kept moist to a depth of 20 to 25 cm. The plantings should receive light water applications daily until the young seedlings come up. About 30 mm of water should be supplied per irrigation. Large fluctuations in soil moisture content will result in poor quality roots that are malformed and have many small hairs or side roots.
6. Weed control
Weeds must be controlled before they can compete with beet seedlings and interfere with their growth. All weeds between the rows must be removed by hand to avoid damaging the roots. Weed control can also be achieved chemically by applying herbicides and instructions on the container should be thoroughly followed.Harvesting methods The crop is lifted by hand or mechanically when grown on a large scale, by using a machine which lifts the crop from the soil and cuts off the leaves. For the crop which is to be marketed fresh, the leaves are not removed. Care should be taken in pulling roots from the soil and in their handling so that damage from bruising can be minimised.