ROSELLE PLANT

ROSELLE PLANT (Hibiscus sabdariffa)

The roselle plant is a member of the hibiscus family, Malvaceae. The shrub can grow up to 2.25m high and produces white to yellow flowers which sit on a stout fleshy red coloured calyx. In Kenya, the herb is found in Western and Nyanza provinces and is an emerging herbal crop of economic importance.

• The calyces are high in Vitamin C and dietary fibre. They are also a useful source of calcium, iron, vitamins B2 and B3.
• The leaves and flowers have been found to posses medicinal properties.
• The drink reportedly possesses anti-hypertensive, diuretic and mild laxative properties, and contains abundant amounts of natural antioxidants such as vitamin C and anthocyanins. 

Uses

•   Roselle is mainly grown mainly for the petals or calyces  of the flower which are used to prepare herbal drinks, beverages, jams and jellies, paste, sweets, syrup, and for wine preparation; its manufacturing residues can also produce vinegar of very good quality 
•  The young leaves and tender stems of roselle are eaten raw in salads or cooked as greens alone or in combination with other vegetables, with meat or fish. They are also added to curries as seasoning.

Other Products

·        Roselle seeds contain 17% oil

·        The plant can also be turned into an alternative cut-flower material for flower arrangements, after the removal of its leaves.

·        The stems of the roselle plant also yield a fibre that can be used as a substitute for jute in making burlaps

Prospects for  Roselle Production

• Roselle is multipurpose crop which can provide food and cash income as a vegetables and processing of various products using. 
• Dried roselle has a huge market potential for export and local market. The demand for roselle products is likely to increase as a result of the rising interest in natural herbal products. Currently, Malaysia supplies much of the Roselle raw material globally

Ecological Requirements

Altitude

It grows at from 0- 600 m above sea level

Rainfall

Roselle grows well in areas with well-distributed rainfall of 1500 - 2000 mm per annual. However the plants are fairly drought tolerant and can grow in areas with as low as 640 mm annually.

Rain or high humidity during the harvest time and drying can downgrade the quality of the calyces and reduce the yield.

Temperature
Roselle need a very warm soil to germinate, preferably over 25°C. Temperatures should not be below 21⁰ C for 4-8 months with night time temperatures an annual temperature in the range of 13 - 28°C

Soil

Roselle grows well in grows in a wide range of soil types however well-drained fertile soils rich in organic matter are best for production. The soil pH should be within the range of 4.5 -8.0. It does not tolerate water logging.

Photo periodism

Roselle grows well in full sunlight and withstands drought quite well. it requires 13 hours of sunlight during the first 4-5 months of growth to prevent premature flowering.

Plants are sensitive to the length of daylight and do not flower if there are more than 13 hours of light in the day

Propagation

The roselle plant is easily raised from seeds or stem-cuttings.

·        It can be planted outdoors in the ground or in containers as long as the plant receives direct sunshine for at least 6 hours daily.

·        It is also grown as a hedge crop, or intercropped with other crops.

·        It is commercially grown as a pure stand crop. The seeds germinate easily so can be planted directly in the field

Land Preparation

Roselle is a deep rooted crop and requires deep ploughing. Planting is by direct seeding with 2 seeds per hole at about 2.5 cm deep at beginning of rainy season.

Seeds rate is 6-8 kg/ha and. Seeds are usual
 

Spacing
The spacing of 80–100 cm within the rows and 60–80 cm apart between the plants may be used.
 

Fertilizer

Manure -500-1000kgs per acre can be applied during planting 
 

Weeding

Timely weeding should be done

Diseases and Pests

Major diseases of hibiscus are stem rot and root rot. Prevention techniques include monitoring the water content in an irrigated field, and avoiding the planting of other crops that are also prone to these diseases. Insect damage is minor, but it does exist; pests include stem borer, flea beetles, cotton bollworm and cutworm. Mealy bugs and leafhoppers are minor concerns, as is the cotton stainer.

Harvesting

•  The calyces should be ready for harvesting 20 days after flowering. The inside seedpod should be still green when fruit is picked, although fruit can remain on the plant until the pods mature and seeds disperse
•  Fresh calyx yields range from 4–6.5 t/ha, or about 800–1200 kg/ha when dried to 12% moisture content. A single roselle plant may yield as many as 250 calyces, or 1–1.5 kg fresh weight depending on environmental conditions and management.
•  Yield for leaves, is about 10 tons /ha.
•   Calyces are harvested manually 2–3 weeks after flowering, usually 4–6 months after sowing, before the fruit has dried and dehisced. Regular picking prolongs flowering. The calyces are dried in the shade.
• Young shoots and leaves are harvested when required.
• When harvested for fibre, stems are cut before flowering, 4–5 months after planting.  Fibre quality declines rapidly after the start of flowering.
•  The calyx is separated from the seed pod by hand, or by pushing a sharp edged metal tool through the fleshy tissue of the calyx separating it from the seed pod. Care should be taken during harvesting to avoid contamination by extraneous material
• The more time the capsule remains on the plant after the seeds begin to ripen, the more susceptible the calyx is to sores, sun cracking, and general deterioration in quality.

Drying

Roselle withers rapidly when fresh and as such cannot be kept for long time or exported over long distances. In Kenya  roselle calyces are air dried prior to marketing. Drying in the sun can lead to reduced quality. Adequate ventilation is important. Plastic sheets are placed on the ground to avoid contamination with soil, which also strongly reduces the value. Drying by artificial heating is capital-intensive

Dried roselle has a huge market potential

Use forced air driers.
 

Post Harvest

Store fresh at 7-10 ⁰C at a humidity of 90–95%.