This nightshade species probably originated in the warm, humid forests of West and Central Africa where it remains today as one of the most important vegetables for home consumption and income production. It is grown as an annual or short-lived perennial.
The fresh leaves and young shoots are cooked and the same are used as fodder for cattle and goats. The ripe fruit is not eaten in Africa but used as a medicine for diarrhea, eye infections or jaundice. The green fruit--and to a lesser extent the leaves--contains two alkaloids, solanine and solanidine, which when accumulated in the body in large quantities, can cause liver damage and/or blindness. The amount of dangerous alkaloids contained in plants probably depends on the cultivar and where the plant was grown.
- Elevation: up to 2000 m (6500 ft)
- Rainfall: 500 mm (20 in), wet leaves encourage disease
- Soil types: a range of soils high in organic matter, 6 - 6.5 pH, better growth when potash and nitrogen are added
- Temperature range: 20-30º C (68-86º F)
- Day length sensitivity-none. Seed may be broadcast or sown directly in rows 15-20 cm.(6-8 in) apart (farther apart in rainy season), cover with layer of fine soil and coarse, cut grass as mulch. Harvesting 1 - 3 times/week can continue over 7 weeks or year-round if wild nightshade is included.
Harvesting and Seed Production
Lower yield but earlier harvest can be achieved by planting 20-30 cm (8-12 in) cuttings. When harvesting, leave at least 10 cm (4 in) so the stem will resprout. The plant may be uprooted and put in water to stay fresh for market. Seeds remain viable for several years if kept dry and cool. Poor germination is most often due to poor cleaning of the seeds and improper storage.
Pests and Diseases
Nightshade is susceptible to similar pests and diseases as tomatoes and potatoes. There are “late blight” resistant cultivars in Cameroon. Spacing plants so that air circulates freely, rotating the crop with amaranth and dusting the leaves with ashes have been found to be successful against common diseases and pests.
Cooking and Nutrition
Baking soda added to the cooking water will reduce the bitterness (likely caused by above-mentioned alkaloids) of the cooked leaves but also leaches out some of the nutrients. Bitterness can also be reduced by discarding the cooking water, which should not be consumed and by adding vinegar to the cooked greens. Ripe cooked fruit is made into preserves and jams.