Sisal: a truly local crop

The term 'sisal' may refer either to the plant's common name or the fibre produced, depending on the context.

Sisal belongs to a species in the Agave genus of the monocotyledon group of plants. In the past, several species of Agave were used for fibre production; today, Agave sisalana is the commercially grown species. In South Africa, the crop is grown in Limpopo (Mokopane, Polokwane, Giyani and Mhinga), KwaZulu-Natal (Hluhluwe, Mtubatuba and Port Shepstone), and Madikwe in North West.

High-grade sisal fibres are made into yarns (either on their own or in blends with wool or acrylic), and used in carpets.

Medium-grade fibres are made into ropes and baler twine. These are particularly useful in a marine environment as they resist deterioration by salt water.

Sisal biomass pulp is a substitute for wood fibre and adds bulk to paper and cardboard. It is also absorbent and has high fold endurance, making it a useful input for paper products.

Sisal can substitute or enhance fibreglass for reinforcing plastic in cars, boats, furniture, water tanks and pipes. It can also add strength in cement mixtures for the development of low-cost housing and replace asbestos in roofing and brake pads.

Remarkably, sisal is strong enough to polish steel, yet soft enough not to scratch it.

THE PLANT

Sisal is a hardy plant that grows well all year round. It lasts from seven to 12 years and produces between 180 and 240 leaves, depending on location, altitude, level of rainfall and plant variety.

White, short (0,9m to 1,8m in length), fleshy stems or rhizomes develop from underground buds at the base of the plant, first growing sideways and then upwards to form new plants.

The plant has a shallow, fibrous root system that grows up to 60cm deep. The roots that are used for propagation develop mainly horizontally and form suckers.