(i) General background on the plant
Sisal is a native of the Yucatan Peninsula, Mexico . Sisal grows best in a hot climate and may be grown throughout the humid and sub-humid lowland tropics.
Sisal is a perennial succulent which, with good growing conditions forms an inflorescence after 6 - 9 years after having produced 200 - 250 leaves, and then dies. Leaves average 120cm in length and are arranged spirally around the thick stem. The leaves are 75% schlerenchyma bundles. The root system is shallow but extends up to 3.5m from the stem.
As a cactus, Agave plants survive and produce a marketable product in infertile arid regions which in many cases would otherwise be unproductive. As it is a labour intensive crop it offers at least stability for a large rural population .
There are three other closely related species also of commercial importance: Agave fourcroydes, Yucatan sisal which produces henequen hemp of Mexico; A. cantala the Maguey sisal of the Philippines; and A. letonae which produces the Salvadorian henequen hemp of San Salvador.
(ii) Details of quality characters
It is the most important of the group of hard fibres, which includes New Zealand flax and Manila Hemp . Sisal is essentially a commercial crop hardly ever grown by small-scale farmers except as hedges. This crop requires large scale production to justify the use of expensive machinery required. The greatest demand for sisal is for use as binder twine, but it can also be used to make ropes, sacks and bags of various types as well as marine cordage.
(iii) Current production and yields 
Sisal occupies 6th place among fibre plants, representing 2% of the world's production of plant fibres (plant fibres provide 65% of the world's fibres). The world's largest producers are Brazil (199,000t), Kenya (40,000t), Tanzania (28,000t) and Madagascar (20,000t). There are significant exports only from Brazil (65,000t), Kenya (31,000t), Tanzania (18,000t) and Madagascar (9,000t).
In the countries of production about 50 leaves, each weighing up to 1 kg may be cut per plant per year. The ripest lower leaves are cut first and this continues periodically over the next four years. On average, over the first 4 years, two cuttings are made annually. In following years only one cut is made per year, until the flower stalks begin to develop. A total of about 300 leaves may be harvested during the economic life of each plant, giving a total of 500 - 600 tonnes fibre/ha. Over the usual 8 year production period, the average annual yield is 67 leaves; about 2.25 tonnes fibre/ha. The crop dies after producing the inflorescence and bearing a crop of vegetative bulbs, when the plant is 8-10 years old.
(iv) Constraints on production
Sisal is essentially a plant of the tropics and subtropics and production benefits from temperatures above 25°c and plenty of sunshine.
(v) Markets and market potential 
Long fibres (>90cm long) are used for ropes and binder twine. Approximately 25% of the fibres are shorter (flume tow and tow fibre), and these are used for padding, mats and stair carpet, also for paper and building panels. After fibre extraction 95 - 96% of the leaves' weight still remains, this is used as fertiliser, or the dried pulp as a fuel for methane production (experimental).
(vi) Other information 
Sisal prefers a rainfall of not less than 1000 to 1500 mm p.a.. The more even the rainfall distribution the higher the quality of fibre and opportunity for continuous leaf harvesting. The crop generally prefers a medium or light soil , with a pH between 5.5 and 7.5.
Fertiliser application: A superphosphate fertiliser applied at about 25 kg P/ha/annum with about 50 kg/ha N applied as calcium ammonium nitrate or urea ensures a good crop. Apply lime where the pH of the soils falls below 6.5 . Where rainfall levels are good, nitrogen can be supplied by growing leguminous cash crops in-between rows.
It has also been known to have a sizeable demand for calcium as a nutrient and frequently responded to small dressings of lime when grown acid soils. The crop is also susceptible to boron deficiency .
The yield deteriorates over the year, and more rapidly under continuous cultivation. Soil potassium deficiencies are indicated by a bending-over of the normally straight and stiff older leaves. Boron deficiency which causes leaf cracking is more difficult to control. Decorticating wastes including both liquids and solids have proved effective as a fertiliser supplement, especially when supplemented with lime .
Propagation of sisal is by means of bulbils which appear on the flower stalk, or by suckers growing around the base of the plant. Plants produce up to 4000 bulbils/plant compared with less than a quarter of this number of suckers, hence bulbils are preferred for propagation . Only large bulbils should be selected for planting. Bulbils are first planted into nursery beds at spacings of 25-30 cm apart in rows 50 cm apart. The bulbils are allowed to grow to about 40 cm or until they are about 9-12 months old , after which they are transplanted to the field. At this time the bulbils have good roots . The growth of bulbils is improved by mulching sisal nurseries with grass, paper or polythene. Mulching with partially rotted sisal gives best results.
Transplanting takes place preferably at the beginning of the rainy season. A recommended planting pattern in the field is a series of double rows 60 cm apart with a 2.5 m alley between pair of rows. Plant spacing is at 75 cm, giving a population of about 25000 plants per hectare. Alternatively plant can be spaced 1 m apart in 3 m rows .
The crop should be kept weed-free and annual legumes such as beans may be cultivated between rows to suppress weed growth and limit erosion .
Pests and diseases :
The plant has a leathery epidermis and some species have sharp spines for protection. Only pest known to occasionally reach pest proportions is the Sisal Weevil ( Scyphophorus interstitialis ).
Harvesting and processing:
In the countries of production and optimal production cutting of the leaves takes place 18-24 months after planting. More usually plants are harvested after 24-36 months. About 50 leaves, each weighing up to 1 kg may be cut per plant per year. The ripest lower leaves are cut first and this continues periodically over the next four years. On average, over the first 4 years, two cuttings are made annually. In following years only one cut is made per year, until the flower stalks begin to develop. A total of about 300 leaves may be harvested during the economic life of each plant, giving a total of 500 - 600 tonnes fibre/ha.
Fibre Extraction: A process of decortication is used to extract the fibre from the leaf tissues. Leaves are crushed and beaten by a rotating wheel set with blunt knives, so that only fibres remain. All other parts of the leaf are washed away by water. Decorticated fibres are washed before drying in the sun or by hot air. Proper drying is important as fibre quality depends largely on moisture content. Artificial drying has been found to result in generally better grades of fibre than sun drying. Dry fibres are machine combed and sorted into various grades, largely on the basis of the previous in-field separation of leaves into size groups .
See the following pages in the NF-2000 Database
Participation in Future Research Projects - Technical University of Berlin, Institute of Non-Metallic Materials
UK - MAFF Project: UK-Grown Non-Wood Fibres: Meeting the needs of industry
1. Sisal - Tanzania and its plantations, Günther Bachthaler.
2. Yayock, J. Y.; Lombin, G.; Owonubi, J. J. Crop Science and Production in Warm Climates. Published 1988 by Macmillan Publishers Limited, London and Basingstoke.
3. Webster, C. C.; Wilson, P. N. Agriculture in the Tropics. Published 1980 by Longman Group Limited, Hong Kong.
4. Rehm, S and Espig, G. (1991). The Cultivated Plants of the Tropics and Subtropics.