Introduction – Onion Farming in Zambia
Onions are essential in most kitchens worldwide, and many Zambian vegetable farmers consider planting the crop. It is a good cash crop in Zambia. Over the years, onion farming in Zambia has seen a steady increase in demand.
In this blog post, you will learn everything there is to know about small-scale onion farming in Zambia. From soil preparation to marketing and storage.
Table of Contents
Onion Yield Per Hectare in Zambia
Onions generally have a good yield in Zambia. A well-managed Onion crop should yield 900 to 1200 x 10kg pockets/ Hectare.
Climate and Soil Considerations
Onions thrive in well-draining and fertile soils with a PH level between 5.8 and 6.8. Before planting your onions, always ensure the soil is free from debris and weeds that can hinder the growth of the crop.
Onions also require cool conditions during vegetative growth and hot, dry conditions nearing maturity, in early summer. Optimum temperatures for growth are 12ºC to 24ºC, with minimum temperatures of 7ºC and maximum 29ºC.
Seed Selection and Planting
Selecting high-quality seeds is the first step towards a bountiful crop. In Zambia, the best onion varieties are Texas Grano, Red Creole, and Caledon Globe.
Sow directly by drilling in farrows 5 mm deep or raise seedlings in nursery beds and transplant 4 to 5 weeks later. The ideal sowing time is February to June.
Transplant during the cool part of the day (early morning or late afternoon) to avoid wilting of the plants.
Space the plants at 5 cm between plants and 20 cm between rows (x 5 rows) followed by 100 cm of walking space every after 5 rows to give a plant population of 500,000 plants /ha.
Irrigation and Water Management
The methods of irrigation commonly used for onion production include drip, sprinkler (overhead), and furrow irrigation.
Drip irrigation is the most sustainable irrigation method for onion production because it minimizes off-site soil and nutrient losses, decreases the risk of onion rot and disease, and conserves water with more precise application in comparison to other irrigation methods such as sprinklers and furrows.
Drip irrigation is also good for tomato farming in Zambia. Always remember to have a consistent watering schedule to ensure you don’t underwater and over-water your crops.
Fertilization and Nutrient Management
Onion farming in Zambia can be very profitable if done right, but to harvest a good yield, you need to pay attention to soil nutrients and fertilization. Follow these steps to achieve proper fertilization for your onions.
- At planting apply Veg Mix C 80 gm /m2 – Broadcast.
- 21days after germination top dress using Veg Top 24 20-30gm/m2 (50 kg/Lima) – Broadcast.
- 35days after germination top dress using Veg Top 24 20-30gm/m2 (50 kg/Lima) – Broadcast.
- 49days after germination top dress using Veg Top 24 20-30gm/m2 (50 kg/Lima) – Broadcast.
- 63days after germination top dress using Veg Top 24 20-30gm/m2 (50 kg/Lima) – Broadcast.
Pest and Disease Control
Pest and disease management is crucial for obtaining higher marketable bulb yield and good quality bulbs. Major pests and diseases of onion, their symptoms, and management practices are given in Table and Fig. In addition, the following points need to be considered for pest and disease management.
- Initiate foliar sprays of pesticide from 30 days after transplanting or as soon as pest/disease appears in the field
- Spray at 10-15 days intervals depending upon the intensity of pest/disease
- Always add spreader @ 0.5-1.0% to spray solution
- Avoid repeated application of pesticides belonging to the same class
| Pest/disease | Pest | Symptoms | Control measures |
| Insect | Thrips (Thrips tabaci) | 1. Planting two rows of maize or one outer row of maize and one inner row of wheat as a barrier crop surrounding an onion crop (250 sq. m) at least 30 days before transplanting helps block the movement of adult thrips 2. Spray insecticide when the thrips population crosses the economic threshold level of 30 thrips/plant 3. Foliar spray of insecticides like Profenofos (0.1%), carbosulfan (0.2%) or Fipronil (0.1%) depending upon the severity of the the infestation | 1. Planting two rows of maize or one outer row of maize and one inner row of wheat as a barrier crop surrounding an onion crop (250 sq. m) at least 30 days before transplanting helps block the movement of adult thrips 2. Spray insecticide when the thrips population crosses the economic threshold level of 30 thrips/plant 3. Foliar spray of insecticides like Profenofos (0.1%), carbosulfan (0.2%) or Fipronil (0.1%) depending upon the severity of the infestation |
| Eriophyid mite | 1. Thrips infestation at the early stage (transplanting to 45 days) can be identified by curling and twisting of leaves 2. A typical symptom of onion thrips is the presence of white or silvery patches on the leaves 3. In severe infestation, whole plant looks blemished and turns white. | 1. Spray Dicofol (0.2%) as soon as the symptoms appear in the field. Repeat the spray after 15 days, if necessary. 2. Foliar spray of sulphur @ 0.05% | |
| Disease | Purple bloch (Alternaria porri) | Spay fungicides, Mancozeb @ 0.25% / Tricyclazole @ 0.1% / Hexaconazole @ 0.1% /Propiconazole @ 0.1% at 10-15 days intervals from 30 days after transplanting or as soon as the disease appears | 1. Initially small, elliptical lesions or spots that often turn purplish-brown which are surrounded by chlorotic margin. 2. If the spots enlarge, the chlorotic margin extends above and below the actual lesion. Lesions usually girdle leaves, causing them to fall over. Lesions may also start at the tips of older leaves. |
| Stemphylium blight (Stemphylium vesicarium) | 1. Leaves do not open completely. The whole plant shows curling. 2. Yellow mottling is seen mostly on the edges of the leaves. | Spay fungicides, Mancozeb @ 0.25% / Tricyclazole @ 0.1% / Hexaconazole @ 0.1% /Propiconazole @ 0.1% at 10-15 days intervals from 30 days after transplanting or as soon as the disease appears | |
| Anthracnose/Twister Disease (Colletotrichum gleosporiodes) | 1. Soil treatment with Benomyl @ 0.2% 2. Foliar Spray of Mancozeb @ 0.25% 3. Planting onion on the raised bed 4. Avoid waterlogging | 1. Seedlings topple over after they emerge from the soil. It usually occurs at or below the ground level and infected tissues appear soft and water-soaked | |
| Damping off disease | Symptoms first appear as straw-colored, dry, tan, spindle, or diamond-shaped lesions, with or without distinct green centers with yellow or tan borders on leaves. The symptoms are more pronounced on flower stalks. Infected leaves and stalks lodge during the latter part of the growing season. | 1. The characteristic symptoms are curling, twisting, chlorosis of the leaves, and abnormal elongation of the neck (false stem). 2. Initially pale yellow water-soaked oval sunken lesions appear on leaf blades. Numerous black colored slightly raised structures are produced in the central portion, which may be arranged in concentric rings. The affected leaves shrivel, droop down and finally wither. | |
| Viral diseases | 1. Planting onion on the raised bed 2. Seed treatment with Thiram or Captan @ 0.3%. 3. Drenching the nursery beds with Captan or Thiram @ 0.2% Carbendazim @ 0.1% or Copper oxychloride @ 0.3% | 1. Plant high-quality transplants free from thrips and Iris yellow spot virus. 2. Practice three years or longer rotation between onion crops. 3. Eliminate volunteers, culls, and weeds in and around onion fields. 4. Avoid crop stress. 5. Thrips control may provide some reduction in iris yellow spot, but thrips control alone is not sufficient to economically control the disease | Iris Yellow Spot Virus (IYSV) |
| Onion yellow dwarf virus (OYDV) | 1. Thrips infestation at the early stage (transplanting to 45 days) can be identified by curling and twisting of leaves 2. A typical symptom of onion thrips is the presence of white or silvery patches on the leaves 3. In severe infestation, the whole plant looks blemished and turns white. | Mild chlorotic stripes to bright yellow stripes, mosaic, curling of leaves, and stunted growth |
Weeding and Intercropping
Weeds compete with plants for nutrients and space; they can reduce yields by more than 25%. Keep the field free from weeds at all times.
Ensure the soil maintains a constant moisture level, especially during the vegetative development stage.
Scout the field for pests and diseases once weekly, and spray if a disease or insect pest is noticed. Leaf miners and Grasshoppers are common Onion insect pests while Purple blotch and Downy mildew are common Onion diseases.
Stop irrigating when the bulbs reach maturity to harden and dry them in readiness.
Final Thoughts On Onion Farming in Zambia
We hope you have gained more insight from this blog post about onion farming in Zambia. Zambia has favorable weather conditions that support the growth of onions