Corchorus olitorius (Ewedu) was first described by a Swedish botanist, physician and zoologist named Carl Linnaeus, who derived the name from an Ancient Greek word Korkhorus or Korkoros, the word referred to a wild plant of uncertain identity. It’s a genus within the familyMalvaceae, under the subfamily Grewiodeae, it has about 100 species which have a pantropical distribution (i.e. across the tropics which are tropical and subtropical regions). Corchorus olitorius has different common names in different places such as in North Africa and the Middle East it’s called malukhiyah, in Turkey and Cyprus, it’s known as molohiya or molochas, while in Nigeria to the Yorubas it is known as Ewedu and to the Hausas, it is known as Rama
Corchorus olitorius grows tall and could reach a height of 2-4m, it can be either unbranched or with only a few side branches, the leaves are alternate, simple, lanceolate, 5-15cm long, with an acuminate tip and a finely serrated or lobed margin, while the flowers are small (2-3cm diameter) and yellow, with five petals; the fruit is a capsule which has many seed and can be grown throughout during the year.
Corchorus olitorius prefers very fertile soil and a hot humid climate; it can tolerate very wet conditions but not waterlogged soil. It can tolerate annual precipitation between 40 and 429m, an annual average temperature range of 16ºc to 25ºc and a pH in the range of 4.5 to 8.2. Corchorus olitorius can be grown annually.
- Land Clearing- This involves slashing of grasses and shrubs on the allocated plot. Thereby opening the topsoil, the land should also have a good drainage system to enable the easy flow of water in order to prevent erosion and flooding thereby causing the soil to be waterlogged.
- Tilling- This operation is necessary for vegetable production to ease the preparation of beds and allow clear aeration of the soil, it can be carried out using basic farm equipment such as a hoe, spade or garden fork by turning and breaking of topsoil to smaller and finer soil particles.
- Preparation of Bed- The bed should be about 1.0m with a furrow of 0.5m, the essence of the furrow is to allow easy passage when carrying out post planting activities such as watering, weeding, fertilizer application, spraying etc.
- Manuring- Organic manure like dried poultry dropping can be used
- Spraying of Insecticide- This should be done with a knapsack sprayer before planting so as not to contaminate the plants.
- Drilling method- This is a method for planting small-seeded vegetables in rows. Shallow furrows are made at the spacing recommended for the crop and the seed drilled along the furrows (for Corchorus olitorius draw rows on the bed with a spacing of 30cm and planting depth of 0.2m) is preferably used when planting Corchorus olitorius, because it reduces overcrowding of the crop and eases all other post-planting operations. The seeds should be mixed in wood ash (sieve the wood ash before mixing it with the seeds) before broadcasting, this helps to prevent root-knot in young plants.
- Watering of Beds- Wetting of bed should be done twice daily, early in the morning and in the evening; this should be done into the harvesting period.
- Weeding- The seeds start germinating 3 or 4 days after planting, weeding would start 2 weeks after germination.
- Thinning and Supplying- Thinning is the process whereby you reduce plants in overcrowded area to give or to make room for the growth of others and Supplying is the practice of providing missing stands of vegetables planted by direct sowing as a result of poor emergence or when seedlings are damaged by pests. The essence of seed supply is to maintain correct plant population. Supplying of seeds has to be carried out as early as possible after emergence; both operations should be carried out after first weeding.
- Supply of Wood Ash- It should be applied to prevent root-knot by nematodes.
- Mulching- A mulch is a layer of plant residue or other materials which is applied to the surface of the soil in order to reduce evaporation, run-off or to prevent weed growth. The purpose of mulching is to conserve soil moisture. Mulching also ensure clean fruit, hasten maturity and increase yields. This operation should be done 3 weeks after planting.
- Fertilizer Application- Fertilizers like Urea is best for leafy vegetables, but its best one makes use of both Fertilizers and organic manure.
- The Corchorus olitorius should be ready to be harvested 3 to 4 months after Planting, harvesting stops when no new leaves are formed or when there is no stand. Harvesting can either be manual by handpicking the fresh leaves or cutting the tender shoots.
Pest and Diseases
- Leaf spot disease
- Root-knot nematode
- Stem girdling beetle
- Grasshoppers (Zonocerus variegatus)
- Low accessibility to latest high yielding varieties
- Wrong use of fertilizer dose
- Mostly the product is sold on the harvest day and it is constantly kept wet, if cooled to 20ºC, it can be kept for a week.
- If the leaves are dried and pounded to powder, the products can be kept for at least half a year.
Source: Agriculture Nigeria