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| Onion, tomato, cabbage salad |
Red Creole -This is a popular high yielding variety of bulb onions which is in high demand due to its good keeping quality, mainly producing single bulb onions from transplants, and they are red, flat-round and with a pungent taste.
Red Tropicana F1 Hybrid- this produces large, red, thick flat bulb onions with firm pungent taste. It is high producing and needs high levels of management.
Bombay Red- Is are bulb onions variety for dry and warmer conditions producing small to medium sized bulbs, which are globe shaped, purplish red and pungent.
Yellow Granex FI Hybrid- Granex F1 hybrid is an early maturing as well as high yielding variety with attractive, thick flat bulb onion and thin yellow scales. It attracts high market prices due to its uniform shape, size and good storage quality.Bulb onions plants require cooler weather during the early stages of growth with a dry atmosphere and moderately high temperature for bulb formation & maturation. Bulb onion plants thrive well in warm to hot climates of 15-30°C, with Optimum temperatures for plant development ranging between 13 and 24°C.Bulb onions plants require light well drained soils with a PH of 6-7 and high fertility. Bulb onions plants need a substantial amount of water at bulb stage, but excess moisture must be avoided throughout the growing season. Irrigation is necessary especially on light sandy soils and can either be overhead or on drip irrigation. Stop irrigating the plants 2-3 weeks before harvesting, or when 20-30% of the tops collapse.
Bulb onion plants are most commonly propagated using seeds which are first sown in a nursery to enable selection of strong healthy seedlings for transplanting. The seed rate is 2-3 kg per ha.
To make the nursery prepare raised beds a metre wide and work in plenty of well decomposed manure as well as rock phosphate. Make drills about 15 cm apart, sow the seeds and cover lightly with soil and mulch. Irrigate the bed liberally for the first 10 days and continue watering the seeds regularly. Germination of seeds takes about 21 days after which the mulch is removed and used to make a shade above the tender plants. Transplanting of seedlings is done about 6-8 weeks after sowing, when the seedlings have pencil thick base and a height of approximately1 5cm. The ultimate yield of bulb onions is determined by the number of leaves that are formed prior to bulb formation; therefore seedlings should have 3 to 5 well formed leaves at transplanting time. Two weeks before transplanting reduce the shade to improve seedling survival rate in the field.
Incorporate well decomposed manure into the soil, at a rate of 25 to 40t/ha to obtain vigorously growing plants. Avoid application of fresh manure to the plants, as it will cause development of thick necks and excess leaves at the expense of bulb formation. Transplanting of seedlings is done in cool weather either in the morning or evening. Water the nursery bed thoroughly for ease of uprooting seedling for transplanting, and then make rows in the field 30cm [12’’] apart. Uproot the healthy strong seedlings leaving the weak seedlings to strengthen for planting latter. Prune the roots for better plants establishment. Plant the seedlings at a spacing of 10cm [4’’] within the row and 13mm [1/2’’] deep, and then firm up the surrounding soil. Irrigate the field before and after transplanting seedlings or alternatively transplant seedlings during the rains when the soil is moist.
There are many pest and diseases that attack onions plants some of which are onion thrips, leaf miners, purple blotch, bacterial soft rot, leaf blight and downy mildew. These can be controlled using cultural control methods which include use of disease free seeds, harvesting mature bulbs only to avoid rotting in store, uprooting and burning isolated diseased plants, keeping the field free of weed plants to avoid alternative host, crop rotation and field hygiene,
maintaining good air circulation during curing, packaging and storage of bulb onions. Chemical control is an option when infestation is severe.The field should be kept free of weed plants throughout the growing season Harvesting takes place 90-150 days after transplanting seedlings and bulb onions are ready for harvesting when the leaves collapse, or alternatively the leaves can be bent over and left to dry for 10-12 days. Pull mature bulb onions manually from the soil and cure them in the sun for 10-14 days with the bulbs covered by the leaves. Cut dried leaves 3.5cm [1.5 inches] from the stem and remove the roots, then grade bulbs according to size & quality. Pack in jute or net bags for storage or immediate sale. Yields of Bulb onions can go up to up to 20 tons per hectare.For more information read
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