Crops Kenaf (Hibiscus cannabinus)

Seedlings

Kenaf plants are annuals, developing strong taproots; top growth varies with variety and growing conditions. Stems may attain heights between 2 and 5 m.

Leaves

Leaves (which are individually stalked) are usually lobed to some extent, while both stems and leaves may develop a red colouration.

Flowers

The flowers are yellow or white, usually with red centres, and are very short-lived. The fruits, when formed, are fleshy, but no varieties yet examined under European conditions have produced seeds. Kenaf requires a deeply- worked soil to be productive. It has no frost resistance, so should be sown in late spring, to establish a population of about 50 plants per square metre; fertiliser requirements may be met by application of 50 kg per ha each of nitrogen, phosphate and potash.

Harvested crop

For production of good quality fibres, the crop is harvested soon after the commencement of flowering, but if the produce is intended for pulping, plants are allowed to remain until growth ceases or is stopped by frost.

Fibres (short and long)

Yields of up to 20 t per ha of dry material may be possible if growth is not restricted by water shortage or other factors. Further research is needed to confirm the place of kenaf as a suitable alternative crop for the regions of Southern Europe where it can be grown. The leaves may prove to be sources of substances of use in the pharmaceutical and agrochemical industries. Closely-related species such as Abelmoschus esculentus (okra) are also under consideration as potential crops for possible fibre production in addition to the fruits, which may themselves be possible sources of useful chemicals as well as a valuable food crop.