Kenaf was first grown in Africa (western Sudan). Kenaf is a high-yielding and increasingly popular vegetable for the city markets. Contrary to roselle (Hibiscus sabdariffa), it can be grown near the equator. Prospects for increased Kenaf fiber and pulp production are good in view of growing concerns about environmental pollution and dwindling forest resources.
Kenaf leaves have been used in human and animal diets for thousands of years. Kenaf fiber is a biodegradable and environment-friendly raw material suitable for woven and non-woven fabrics, geotextiles and laminated sheets for packaging and paneling. Kenaf stems are an excellent substitute for softwood as raw material for the pulp and paper industry. Kenaf fibers are used for cordage (rope making), animal bedding, grass and flower mats and soil-less potting mixes. The woody core of the stalks is burned for fuel. Ranchers have begun using Kenaf as a green-chop forage crop.
• Elevation: 0-2700 m (9,000 ft)
• Rainfall: needs 500-625 mm (20-25 in) during growth
• Temperature: 16-27o C (60-80o F); frost sensitive
• Soil: well-drained, neutral sandy loams, rich in humus; does not tolerate waterlogging Kenaf adapts to a wide range of climates and soils.
Optimum growth is generally in a long warm growing season and with moderate rainfall preferably backed up by irrigation. Flowering is influenced by the time of planting; long days and high temperatures prolong the vegetative growth phase, an advantage for vegetable and fiber crops. Most cultivars remain vegetative until the photoperiod falls below 12.5 hours. Germination of untreated seed takes about 7 days, longer than for most vegetables; for this reason some farmers soak their seed in water for 24 hours prior to sowing, obtaining emergence after 3 days.
Harvesting and Seed Production
Vegetable Kenaf takes 3–4 weeks from emergence to the first harvesting. From seed, an acre of Kenaf reaches a height of 14 to 18 ft in 3 to 5 months and yields 7 to 10 tons of dry weight fiber. Flowers open before daybreak and begin to close about midday. The flower structure promotes cross-pollination. Kenaf is usually propagated from seed but may also be propagated through cuttings.
Pests and Diseases
Diseases and pests of vegetable Kenaf are similar to those of cotton and okra. Three major problems concerning Kenaf are the disease anthracnose, nematodes and photoperiodism.
Cooking and Nutrition
The shoots or young leaves, and sometimes the flowers and young fruits, are used as a vegetable. The seeds are roasted, ground and pounded, and the flour and skin are separated in water. The flour is rejected but the floating skin parts are used for the preparation of a paste, mixed with boiled pigeon peas. Children chew the bark for its sweetness.
Webber, C.L. III, H.L. Bhardwaj, and V.K. Bledsoe. 2002. Kenaf production: Fiber, feed, and seed. p. 327–339. In: J. Janick and A. Whipkey (eds.), Trends in new crops and new uses. ASHS Press, Alexandria, VA.