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Carrots (Daucus carota)
The carrot is a root vegetable that is often claimed to be the perfect health food. It is highly nutritious, and loaded with fiber and antioxidants.
Climatic Requirements
Temperature
Optimum production temperature is 15 –21 0
At high temperatures, above 25 degrees.
Soils
The growth is slower and short thicker roots with pale colour are produced. Plant in deep, rich light soils. Insufficiently decomposed manure and stony soils cause forking in carrots. The soil pH ranges from 5.5-6.8. Acid soils must be avoided.
Planting
The crop is sown in situ. Can be grown all year round but the best time to plant is May to July. Carrots may be drilled in or broadcast but should be thinned after 1 month to
leave 3– 6 cm apart. The sowing should be at the rate of 3-8 kg/ha.
Fertilization
Before sowing apply a basal fertilizer of 100– 200kg / ha Compound D.
Weed Management
Care should be taken in weeding to avoid damaging roots
Weeds can be kept under control by mechanical means.
Insect Pest Management
Pest
Aphids
Symptom
Sucking pests
Leaves wilt and turn yellow
Control
Dimethoate 40EC at 10ml/10L of water.
Pest
Nematodes
Symptom
Attack the root and cause slow growth
Tubers are deformed, forked or stringy
Control
Crop rotation and use of resistant plants and soil disinfection
Disease Management
Disease
Powdery Mildew
Symptoms
Whitish growth on leaf under surface and later whitish spot appear on both leaf and stem surface.
Control
Application of sulphur in the form of Dithane M45 at 30g/15l water or Benomyl at 30 ml/15 l water
Disease
Leaf Blight
Symptoms
Blackening of foliage which subsequently dies
Control
Dithane M45 20g/ 10L
Copper oxychloride 85% wp 200g/100L every 7 – 10 days
Disease
Bacterial Soft Rot
Symptoms
Reduce the carrots to a soft slimy mass
Control
Growing carrots in well drained soils,
Rotation– do not follow carrots after lettuce or cabbage.
The roots must be kept well ventilated after lifting
Harvesting
Done after 3 months, ideally when the roots are more than 2 cm diameter.
A plough must loose the soil first. Harvest during cooler day times and keep in a cool place or sprinkled with water to maintain the fresh state. The tops are cut off and carrots are packaged in transparent film bags to increase shelf life. The expected yield is > 25 tonnes per hectare with good management.
Storage
The crop can be stored for 6 months at about 0 degree and relative humidity of
93-98 %.
Author; Wallace Mukoka
