Aerial yams, also known as Dioscorea bulbifera, are a unique and underutilized crop gaining popularity in Kenya due to their adaptability, high yields, and nutritional value. Unlike conventional yams that grow underground, aerial yams produce edible bulbils on their vines, making them easier to harvest and store. This guide provides a comprehensive overview of aerial yam farming in Kenya, covering essential aspects from planting to harvesting and post-harvest handling.
History Of Aerial Yams
Aerial yams have a long and fascinating history, dating back to ancient times. Their origins can be traced to Southeast Asia, where they have been cultivated for centuries. From there, aerial yams spread to other parts of the world, including Africa, the Pacific Islands, and the Caribbean.
The earliest evidence of aerial yam cultivation suggests that they were domesticated in Southeast Asia around 5,000 years ago. Their adaptability to various climates and soil conditions, along with their high yields and nutritional value, made them a valuable food source in many regions.
Aerial yams are believed to have been introduced to Africa via trade routes and human migrations. They quickly gained prominence in African cuisine, becoming a staple food in many communities. Their ability to thrive in diverse environments, including dry and humid regions, made them particularly suitable for cultivation in Africa’s diverse landscapes.
Today, in many African cultures, yams hold cultural significance beyond their role as a dietary staple. Yams are often associated with fertility, prosperity, and various religious ceremonies. In some communities, the successful cultivation of yams is considered a symbol of agricultural prowess and abundance.
Site Selection and Soil Preparation
Aerial yams thrive in various climatic conditions, including high altitudes and dry areas. However, they prefer well-drained, fertile soils with a pH range of 5.5 to 6.5. Select a site that receives adequate sunlight and is free from waterlogging.
Before planting, prepare the soil by deep ploughing or digging to a depth of about 30 centimeters. Remove weeds and debris, and incorporate organic matter such as compost or manure to improve soil structure and fertility.
Ecological Requirements On Aerial Yam Farming In Kenya
Climate:
Aerial yams thrive in warm tropical climates, making Kenya’s diverse regions suitable for cultivation. The optimum temperature for growth ranges between 25 to 30 degrees Celsius. Ensure that the yams receive adequate sunlight, as they are sensitive to shading.
Soil Type:
A well-drained, loamy soil with good fertility is ideal for aerial yams. The soil should be loose to facilitate easy tuber expansion. Sandy or clayey soils can be amended with organic matter to improve structure and nutrient retention.
pH Level:
A slightly acidic to neutral soil pH level of 5.5 to 6.5 is preferred for aerial yams. Conduct a soil test to determine the pH of your soil and make necessary amendments using agricultural lime or organic matter to bring it within the recommended range.
Water Management:
Aerial yams require consistent moisture throughout the growing season. Adequate water is especially crucial during tuber initiation and enlargement stages. Implement efficient irrigation methods, such as drip irrigation, to avoid waterlogging and ensure uniform soil moisture.
Propagation of Aerial Yams
The propagation of the crop is either through planting of seeds, which are costly and not widely available locally, or by planting bulbils from harvested plants.
Cuttings of tubers. Small root tubers can be cut into sections. Each section should have 2-3 dormant buds. The cut tuber is dipped in wood ash and left to heal for several hours to promote wound healing and reduce the risk of fungal infection.
Aerial bulbils can also be planted and these produce vigorous plants The aerial bulbils can be divided into two or more equal sized pieces.
The larger the piece of tuber used for propagation, the larger and more productive the plant will be.
Planting Aerial Yam Bulbils
Start by acquiring high-quality planting material, which can be either vine cuttings or bulbils. Select vines that are free from diseases and pests, ensuring they are from a reputable source. Healthy planting material sets the stage for a vigorous and disease-resistant yam crop. Avoid using bulbils from plants that have shown signs of disease or pests.
Aerial yams are typically planted at the onset of the rainy season. This ensures that the soil has sufficient moisture to support the initial growth of the vines. Planting too early may expose the young plants to waterlogging, while delayed planting may result in poor establishment.
The yams are planted just like irish potatoes, but for maximum yield one needs to dig a hole of about one square feet and apply about a bucket of well decomposed farmyard manure, mix the input properly with the top soil before application into the hole.
Prior to planting, prepare the soil by creating mounds or ridges. This aids in water drainage and prevents waterlogging, which can be detrimental to yam growth. Incorporate well-rotted organic matter, such as compost or manure, into the soil to enhance fertility.
Space the planting holes or mounds at intervals of 1.5 to 2 meters. Plant each vine or bulbil at a depth of 5 to 10 cm, ensuring that the growing tip is facing upwards. Proper spacing allows the vines to spread efficiently, preventing overcrowding and promoting better air circulation.
Create mounds or ridges to improve drainage, and space the yam vines or bulbils at intervals of about 1.5 to 2 meters. Plant them at a depth of 5 to 10 cm, ensuring that the growing tip is facing upwards.
Ensure the bulbils have an upright orientation to promote proper growth.
Immediately after planting, water the yam vines thoroughly to promote establishment. Subsequently, water the plants regularly, especially during dry periods. A consistent water supply is critical for the development of healthy vines and the initiation of tuber growth.
Apply a layer of organic mulch around the base of the plants. Mulching helps retain soil moisture, suppresses weed growth, and regulates soil temperature. Organic materials like straw or leaves can be used for mulching, contributing to overall soil health.
Handle the vines with care during planting to avoid damage. Aerial yams are sensitive, and any injuries to the vines can impede their growth. Gently plant the vines or bulbils in the prepared holes, taking care not to break or bruise them.
Trellising and Support
Aerial yams are vigorous climbers, requiring support structures to grow vertically. Install trellises or poles made from bamboo, wood, or metal at the time of planting. These structures should be sturdy enough to support the weight of the growing vines.
Trellising and providing adequate support for aerial yams are pivotal practices that contribute to the overall health, efficient management, and increased yield of the crop. Aerial yams, being climbing vines, exhibit enhanced growth and ease of harvest when provided with the necessary structures for vertical support.
At the time of planting, install sturdy support structures such as stakes or trellises. Choose materials that are durable and able to withstand the weight of mature yam vines laden with tubers. Bamboo stakes or wooden trellises are commonly used, providing a natural and sustainable option.
Place support structures strategically at regular intervals within the planting area, ensuring they are positioned in line with the intended direction of vine growth. Adequate spacing prevents overcrowding, allowing each vine to receive sufficient sunlight and promoting proper air circulation.
As the yam vines grow, carefully train them to climb the support structures. Gently guide the vines upward, helping them attach to the trellises or stakes. This training process not only prevents the vines from sprawling on the ground but also encourages vertical growth, optimizing space utilization.
Consider providing supplementary support for heavier vines or during adverse weather conditions. This can involve tying the vines to the support structures using soft materials such as twine. Ensuring the vines are adequately secured prevents breakage and damage.
Regularly inspect the trellises and support structures to identify any signs of wear or damage. Perform necessary repairs or replacements to maintain the stability of the system. Timely maintenance ensures that the yam vines continue to receive the support they need throughout the growing season.
Weed Control and Pest Management
Regular weeding is essential to maintain soil fertility and prevent competition for nutrients and sunlight. Hand weeding is effective, but mulching around the plants with organic matter can help suppress weed growth.
Pest and disease management practices are crucial to protect aerial yam crops from damage. Monitor the plants regularly for signs of pests such as aphids, whiteflies, and beetles. Use organic pest control methods whenever possible, such as insecticidal soaps or neem oil.
Fertilization and Watering
Aerial yams require moderate fertilization throughout their growing cycle. Apply a balanced fertilizer with a ratio of NPK (Nitrogen, Phosphorus, Potassium) of 1:1:1 every 3-4 months.
Watering is particularly important during dry periods, especially during the initial growth stages. Water the plants regularly, ensuring the soil remains moist but not waterlogged.
Harvesting
When it comes time for harvesting, having a well-supported and organized trellising system makes the process considerably more straightforward. Gently remove the mature tubers from the vines, taking care not to damage the support structures. A well-maintained trellising system contributes to a more efficient and productive harvest.
Aerial yam bulbils mature within 6 to 12 months, depending on the variety and growing conditions. Harvesting involves carefully removing the mature bulbils from the vines.
Profitability Of Aerial Yams In Kenya
If grown under proper care, a single plant is capable of producing 25 yams of over 20Kgs. A single aerial yam for consumption costs 100-150Kshs while for planting ranges around 200-250Kshs.
An acre can fir around 780 plants on 3x2m spacing. Per year a farmer is capable of producing 1.5 to 3Million KShs per acre.
FAQS
1. What is aerial yam farming?
Aerial yam farming is the cultivation of aerial yams, also known as Dioscorea bulbifera. These yams are unique in that they produce edible bulbils on their vines, making them easier to harvest and store than traditional yams that grow underground. Aerial yam farming is gaining popularity in Kenya due to its adaptability, high yields, and nutritional value.
2. How do I start aerial yam farming in Kenya?
To start aerial yam farming in Kenya, you will need to select a suitable site, prepare the soil, and plant the bulbils. You will also need to provide support structures for the vines to climb on. Regular weeding, pest management, and fertilization are essential for successful aerial yam farming.
3. What are the best conditions for aerial yam farming?
Aerial yams thrive in well-drained, fertile soils with a pH range of 5.5 to 6.5. They prefer warm temperatures and moderate rainfall, but they can also tolerate dry conditions.
4. When is the best time to plant aerial yams in Kenya?
The best time to plant aerial yams in Kenya is during the rainy season, typically from March to May.
5. How do I space aerial yam plants?
Aerial yam plants should be spaced 2 meters apart.
6. How long does it take for aerial yams to mature?
Aerial yams typically mature within 6 to 12 months, depending on the variety and growing conditions.
7. How do I harvest aerial yams?
Harvesting aerial yams involves carefully removing the mature bulbils from the vines. The bulbils can be stored for several months in a cool, dry, and well-ventilated place.
8. What are the pests and diseases of aerial yams?
Aerial yams are susceptible to a number of pests and diseases, including aphids, whiteflies, beetles, and nematodes. Regular pest and disease monitoring and control are essential for protecting aerial yam crops.
9. What are the nutritional benefits of aerial yams?
Aerial yams are a rich source of carbohydrates, vitamins, and minerals, making them an essential food source for many communities. They are particularly high in vitamin C, potassium, and iron.
10. How do I cook aerial yams?
Aerial yams can be cooked in a variety of ways, including boiling, frying, and roasting. They can also be eaten raw.
11. Where can I buy aerial yam seedlings in Kenya?
Aerial yam seedlings can be purchased from agricultural supply stores, nurseries, and some farmers.
12. How much does it cost to start aerial yam farming in Kenya?
The cost of starting aerial yam farming in Kenya will vary depending on the size of the farm, the cost of inputs, and the availability of labor. However, it is generally considered a relatively low-cost investment.
13. Is aerial yam farming profitable in Kenya?
Aerial yam farming can be a profitable venture in Kenya. With proper management practices, aerial yams can produce high yields, which can be sold for a good price.
14. What are the challenges of aerial yam farming in Kenya?
Aerial yam farming faces a number of challenges, including pests, diseases, and climate change. Ongoing research and development efforts aim to address these challenges and enhance aerial yam production and sustainability.
15. What are the future prospects of aerial yam farming in Kenya?
Aerial yam farming has the potential to play a significant role in food security and nutrition in Kenya. With increasing demand for aerial yams and ongoing efforts to improve production methods, aerial yam farming is expected to continue to grow in the future.
16. Can I intercrop with aerial yams?
Yes, aerial yams can be intercropped with other crops, such as maize or beans. This can help to increase yields and provide additional income.
17. What is the best way to store aerial yams?
Aerial yams should be stored in a cool, dry, and well-ventilated place. They can be stored for several months without significant loss of quality.
18. Can I export aerial yams from Kenya?
Yes, aerial yams can be exported from Kenya. However, it is important to meet the requirements of the importing country.