Kenyan Farmers have been doing their best to address the demand and close the gap experienced in onions farming, but there is still more supply to be achieved. In this article you will learn on the major challenges affecting onions farming in Kenya.
Red Bulb Onion is a very attractive commercial investment for the Kenyan market at the moment.
Bulb onions take 3 to 4 months to reach maturity.
Short rains are great for bulb onions since they can be harvested between January and February. Local farmers are able to benefit during this time period
Spring onions are easy to plant. You can even plant them at your kitchen garden. They are commonly used in vegetable salads or as seasoning in soups.
Some of the health benefits of spring onions include lower blood sugar and decreasing blood pressure and cholesterol levels.
Common varieties of onions grown in Kenya include, Red creole, Neptune F1, Bombay Red, BSS 230 Hybrid, Red Comet onion among others.
Onion varieties grown in Kenya
1.Red creole –
A thick flat to flat round bulb with moderate firmness
Exterior color of bulb is bright red to bronzy
Interior color of bulb is white with red inner scales
Plant has thin and fairly loose outer scales with a medium basal plate and neck size
Color of plant leaves is medium blue-green
Average maturity: 210 – 220 days
Well adapted with a good yield and store well
2.Neptune F1–
3.Bombay Red–
4. BSS 230 Hybrid
High yielding but highly susceptible to Thrips.
Field trials were conducted at the Kenya Agricultural Research Institute (KARI) centres at Mwea and Thika.
5.Red Comet onion–
6 Texas Grano
Its large, yellowish bulbs and sweet flavored and takes about 100–120 days to mature.
Its mild taste makes it a popular choice for cooking.
Nursery management for onions farming in Kenya
- Prepare the soil so that there are no lumps.
- Raised beds are the most preferred. Dig deep into the bed so the onions can grow good roots.
- Mix well-rotted manure into the soil.
- Plant seeds 8 cm apart in rows 15 cm apart. Cover the seeds with soil.
- Water the seeds and apply mulch.
- Once they germinate remove mulch.
Irrigation
There is need to work with an irrigation system that betters the growth and soil conditions for growth of onion bulbs.
The drop by drop irrigation enhances the soil to be loose and less compact for growth of roots.
Drip irrigation is the best for onions farming in Kenya.
Use beds to grow onions under irrigation with drip lines laid on 2–3 lines per bed.
Drip irrigation is easier to manage and unlike rainfall or furrow irrigation, you can control the rate of water flow to the onion farms.
Onions need water during the planting period, but the ground should be dry when harvesting nears to prevent the bulbs from damage.
Therefore, stop irrigation 2–3 weeks before harvesting.
Manure application/Basal application
You should broadcast manure/compost (10 – 16 tons per acre) then incorporate into the soil using a hoe.
Apply manure 1 to 2 weeks before transplanting the bulb Onions.
Note onions respond very well to well decomposed organic manure.
Transplanting and top dressing bulb onions
Irrigate field well a day before transplanting.
Transplant your seedlings 6 – 8 weeks after sowing, when they have formed 3-5 leaves and are pencil thick in size.
The seedlings are transplanted in trenches at a spacing of 30 cm between rows and 8 –10 cm between plants.
Apply 80 kg/acre of TSP
Top-dressing is done in 2 splits
1st Top-dressing with CAN 30 days after transplanting at a rate of 40 kg/acre.
2nd Top-dressing with CAN 45 days after transplanting at 80 kg/acre.
Ensure you use Strip/banding method, it is more effective hence preferred over broadcasting.
Cultural practices
Unearthing is removal of excess soil around the bulb/loosening soil to allow the bulb to expand or develop well.
Carry out un earthing during 2nd and subsequent weeding and is done by removal of the soil from the bulbs by hand.
Diseases and pests affecting onions farming in Kenya
1.Damping off
High soil moisture and moderate temperature along with high humidity especially in the rainy season leads to
the development of the disease.
You will observe two types of symptoms
Pre-emergence damping-off: The pre-emergence damping off results in seed and seedling rot before these emerge out of the soil.
Post-emergence damping-off: The pathogen attacks the collar region of seedlings on the surface of soil.
The collar portion rots and ultimately the seedlings collapse and die.
Control: Select healthy seeds for sowing and treat with Thiram @ 2g/kg of seed before sowing.
Avoid continuous raising of nursery in the same plot .
2.Purple Blotch (Alternaria porri)
It is an important disease prevalent in all the onion growing areas.
Hot and humid climate with temperature ranging from 21-30°C and relative humidity (80-90%) favor the development of the disease.
The symptoms occur on leaves and flower stalks as small, sunken, whitish flecks with purple colored centers. The lesions may girdle leaves/stalk and cause their drooping.
The infected plants fail to develop bulbs .
Control: Use of healthy seeds for planting and crop rotation of 2-3 years with non-related crops.
Spraying Mancozeb (0.25%) or Chlorothalonil (0.2%) after one month from transplanting at fortnightly interval reduces the disease
PESTS
Thrips
Thrips are tiny insects that can cause significant damage to onion crops in Kenya.
They feed on the plant sap, causing stunted growth and distortion of the leaves and bulbs.
Thrips can also transmit viral diseases like Iris Yellow Spot Virus.
Control. Employ various measures.
1.Good sanitation practices are crucial in preventing the buildup of thrips populations. Farmers should remove weeds, plant debris, and other crop residues from the field, as they can serve as breeding grounds for thrips.
2.Use insecticides to control thrips.
Insecticides containing active ingredients like spinosad, acetamiprid, or chlorpyrifos can be applied as a foliar spray to control thrips.
The application of insecticides should be done according to the manufacturer’s instructions.
Conclusion
Onions farming in Kenya can be a venture of great returns if you as a farmer will follow on good agricultural practices, choose the right variety of seeds, carry out soil test and employ appropriate disease and pest control measures.
This will assist you on minimizing the challenges hence a healthy crop and higher crop yield.
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