African nightshade is another star food plant from the family Solanaceae – the same family that provides tomatoes, brinjals, potatoes and, our previously featured indigenous food crop, the African eggplant.
Prepared in African kitchens, the leaves and fresh shoots of this nightshade offer diversity and nutritive value to the menus of the continent’s people.
Research scientist Matt Styslinger says broad-leafed African nightshade is an “excellent source of protein, iron, vitamin A, iodine and zinc”. Other sources include folic acid, beta-carotene and ascorbic acid in the nightshade’s list of benefits.
Africa’s small-scale farmers have a unique opportunity to grow and market indigenous, nutritious food crops, cost-effectively, to the continent’s consumers.
DESCRIPTION, RANGE AND REQUIREMENTS
- Mnavu, Managu, Mamaska and Osuga are some of the local names given to the popular African nightshade (Solanum scabrum).
- This broad-leafed annual, reaching heights of between 0.5 m to 1 m, is found across the western, central and eastern regions of sub-Saharan Africa.
- Tolerant of many habitat types, it grows in low-lying valleys and in highlands at altitudes of 2 000 m above sea level.
- This nightshade likes direct sunlight and temperatures of between 20°C and 30°C in regions with an annual rainfall over 500 mm.
- It is usually grown as a dryland crop in the long and the short rainy seasons because it is drought sensitive and must have water throughout the growing period.
- Seeds and seedlings in the nursery need daily watering, which may be reduced to twice a week after transplanting.
- Mulching your crop can mitigate against dry periods by protecting and cooling the soil and improving its water holding capacity.
- Use straw, old leaf material, wood chips as mulch and make it part of your farming practice.
- Frost is a no-go zone for African nightshade, so don’t cultivate it in areas that experience frost.
- Like many native plants, it is resilient and will tolerate soils that are less than ideal, but it performs best in sandy loam and friable clay soils with a pH of between 6 and 6.5 (see previous article I wrote on how to test your pH)
- The nightshades are heavy feeders and need N (nitrogen) and P (phosphorus) with decent amounts of organic material added to the soil.
- N is vital for leaf production and without enough of it you will have a smaller leaf area, reduced yield and less money in the bank for the same work. Apply top and side dressings of Urea (N) after every third cut at 60kg/ha.
- Do not be tempted to keep adding N ad lib to get higher yields because too much of it can make the soil toxic.
- Work 5t/ha to 10t/ha of properly decomposed cattle or chicken manure into the soil.
Also read: Make a plan to apply top dresser fertiliser
- African nightshade may be sown year round, as long as there is water available to irrigate the crop.
- An inter-plant and inter-row spacing of 20 cm is recommended for small-scale growers, who harvest leaves continuously during the crop season.
- Growers who have access to more land will get better leaf yields using greater distances of 50 cm between plants and 50 cm between rows.
- If you are planting for a seed crop use even wider spacing, 60 cm X 50 cm or 80 cm X 50 cm.
- Seed can be grown in flat trays or nursery beds, or broadcast directly into the field.
- Because the seed is so fine it is best to mix it with a medium like river sand to help even sowing.
- The fast-growing seedling is ready to transplant a month to 6 weeks after sowing when it is about 7 cm tall.
- Don’t leave it to get too tall because you will get weak plants.
- Flowers appear from eight to 11 weeks and first leaf harvest begins between 8 and 12 weeks after sowing.
- When the leafy stems are cut down (to between 5 cm and 15 cm) side shoots start regrowth immediately.
- After the first cut, growers can harvest every week to 2 weeks for up to 10 cuts. The length of harvested shoot really depends on the cultivar.
- Yields begin to fall off after the 6th cut without enough of the right kind of fertiliser.
- Yields increase significantly (7 t/ha to 27 t/ha) depending on good farming practices, a reasonable fertiliser programme and a solid knowledge base.
There is no better teacher for a farmer than experience, but farming can be an unforgiving business. The experience of your farming friends and neighbours, or family members who have farmed the crop is an invaluable learning resource.
Indigenous food crops are becoming more popular and the African nightshade now appears on supermarket shelves in East African countries, but is found throughout the region in local informal, fresh produce markets.
The one challenge with this crop is that is must be marketed on the same day it is picked. This is difficult, but not insurmountable, for growers who live far from urban areas.
The solution is to form groups and rent or jointly buy a light delivery vehicle. I met a farmer in Zambia who drove 400 km to the Democratic Republic of the Congo’s border every weekend to market his cabbages during the season. He did not do it to break even – he did it because it was profitable.
The high demand for the African nightshade guarantees a strong market, always a winning trait in a commercial crop.
It’s productive, generous, nutritious and popular with consumers, and almost certainly worth a trial, especially if you are a grower with tomato or potato experience and already familiar with the possible disease challenges the solanaceous plants suffer.
Indigenous crop production: The versatile African eggplant
Indigenous crop production: How to grow African eggplant seedlings
Indigenous crop production: Preparing land for African eggplant and managing your crop