Gossypium

Cotton (Gossypium, Linnaeus 1758) is a shrub of the family Malvaceae, native to the Indian subcontinent and the tropical and subtropical regions of Africa and the Americas, and imported to Europe by the Arabs.
Plants in the wild can reach a height of more than 1.50 m and have a long life. The wild species of cotton produces seeds covered only with reddish hairs, while cultivated plants produce longer, clear and spinnable fibers. There are nearly a thousand varieties of cotton cultivated. The main species include: Gossypium herbaceum (or cotton of the Levant), an annual herbaceous plant native to Arabia and Asia Minor, with covered seeds and short fibers; Gossypium hirsutum (or Upland cotton), an American herbaceous plant with covered seeds and long greyish fibers; Gossypium arboreum, a shrub native to Africa, India, China and Japan; Gossypium barbadense (or Sea Island cotton), a herbaceous plant of American origin, with naked seeds and long fibers, cultivated throughout tropical America and Egypt. Gossypium brasiliensis and Gossypium peruvianum are descended from barba dense, whereas varieties such as Gossypium indicum and Gossypium nanking are related to Gossypium arboreum.

Cotton plants are herbaceous or shrubby, those in the wild are perennial, and cultivated crops are mostly annual. They have glabrous or pubescent stems and leaves, reaching very different sizes depending on the species (from 50 cm to more than 3 m). They all have many branches, with palmlike leaves with 3-7 triangular lobes. The solitary flowers, with whole bracts or toothed, are white, yellow or pink, with 3-5 ovary loculi. The fruit is a capsule that opens in 3-5 shells, each of which contains numerous subglobose seeds, oblong, with a varying degree of hairiness. In relation to fuzziness, there are two types of plants: those with long fibers that are suitable for spinning and that detach easily from the shell (nude or black cotton), and those that in addition to long fibres, produce seeds with thick fuzz that remains stuck to the shell when the hairs are broken off. This fuzz is not spinnable, and once it has been removed from the seed in a special procedure it is an important source of cellulose (linter).

Cotton is cultivated in all tropical and subtropical regions, and even, to a limited extent, in some temperate areas. It requires loose and well-worked earth, abundant organic fertilizers and minerals, a warm climate, with frequent rains during development, or irrigation, and instead drought in the period of maturation. It is considered as a renewable plant and a rotation crop; sowing is generally done in spring and reaches maturity in a period of 150-200 days. In addition to the cotton fiber, the seeds are used, from which oil is extracted and used for human food or in the manufacture of soap. The residue (oilcake) is used for ruminant feed or as fertilizers. The shells are used as fuel, whereas organic humus can be derived from the waste from stems and leaves.

Cultivated species

Gossypium arboreum L.

A shrub that can be up to 2 meters high, variable from a morphological point of view, with a stem of varying degrees of fuzziness and with glands. The leaves are palmed with 3-7 ovate or lanceolate lobes, with few or no nectar glands. The flowers are usually yellow with a purple baseline mark. Each capsule has 3 or rarely 4 loculi and in each loculus, there are up to 17 seeds with white or brown fibres, up to 2.5 cm long.

Gossypium barbadense L.

A shrub, sometimes tree-like, up to 3 meters high, with glabrate to pubescent stems, usually equipped with glands. The leaves are palmed, formed by 3-7 lobes, with nectars. The flowers are positioned on up to 4 cm long peduncles, are usually yellow, with purple baseline marks.
The capsules are glabrous, elongated and contain 5-8 free or fused seeds, with white fibers that are longer than 3 cm.

Gossypium herbaceum L.

A shrub up to 1.5 meters high, with usually fuzzy stems, and glands. The leaves are slightly palmed, consisting of 3-5 lobes, with little nectar. The flowers, with stems up to 3 cm long, are yellow with purple baseline marks, with few or no glands. The capsules contain up to 11 seeds with short fibers of less than 2.5 cm.

Gossypium hirsutum L.

A shrubby plant sometimes more than 2 meters tall, branched, with branches of varying degrees of pubescence and with scattered glands.
The leaves have long petioles and are made up of 3-5 poorly-defined lobes. The flowers are cream-colored or pale yellow, with or without a dark spot at the base. The capusules are glabrous, with 3 or 5 loculi, containing 5-11 seeds per loculus. The fibers are white or dark red, of medium length, from 2.5 to 3 cm.

Hybridization

Although cotton is a shrub that usually is easily hybridizable, until the 19th century only new types of cotton occasionally found wild in the fields were selected.
Through hybridization new strains were obtained raising considerable revenues in Egypt, such as Giza 12, Giza 26, Giza 28, Giza 30, and many others.

Hybridization

Although cotton is a shrub that usually is easily hybridizable, until the 19th century only new types of cotton occasionally found wild in the fields were selected.
Through hybridization new strains were obtained raising considerable revenues in Egypt, such as Giza 12, Giza 26, Giza 28, Giza 30, and many others.

Hybridization

Although cotton is a shrub that usually is easily hybridizable, until the 19th century only new types of cotton occasionally found wild in the fields were selected.
Through hybridization new strains were obtained raising considerable revenues in Egypt, such as Giza 12, Giza 26, Giza 28, Giza 30, and many others.

Long staple Egyptian cotton

Egypt has always been the producer of the best cotton in the world, thanks to its particular climate and the fertility of the land near the Nile and its delta.

The heavy rains between October and April, the 60-70% humidity, and the winds from the north keep the temperature stable, creating an ideal microclimate.

These conditions make Egypt the leading historical producer and current world leader in the production of long staple (LS) and extra long staple (ELS) cotton.

Long staple cotton refers to the varieties Giza 86, Giza 89, Giza 90. The high quality of these cottons includes similar features to the American Supima: a fiber length of around 33 mm and micronaire from 4.3 to 4.6. With this quality, thin yarns can be produced, until the count Ne 80/1 (NM 1/135).

The famous extra long staple cottons include the Giza 45, Giza 70, Giza 87 and Giza 88. The longer than 37 mm fibers, with an average micronaire value of 2.95, are of an even higher quality, capable of generating yarns with very fine counts and which are resistant at the same time.

Giza 45 and Giza 87

Similar in quality to Giza 87, Giza 45 is the best extra long staple cotton, the "queen" of Egyptian cotton. In 1820, Mohammed Ali Pasha, the founder of modern Egypt, planted the seeds of Sea Island and Brazilian cotton for the first time in Egypt, enthusiastic about the fabrics produced overseas from this variety of fibers.
The finest cotton in the world was thus born in Egypt, from the combination of the best seeds in the world and the unparalleled climatic conditions of this country.
Giza 45 plants are cultivated only in a small area east of the delta of the great river and represent 0.4% of the total annual production of Egyptian cotton.
Their long fibers (over 43 mm) are also extremely thin (2.95 micronaire) and with a high uniformity index (88.5%). Despite its fineness, Giza 45 is still extremely strong, on average 46.3 grams / tex. In terms of resistance, clean look and regularity, Giza 45 therefore is in a league of its own in terms of excellence. An ideal cotton for the production of very fine and strong yarns and fabrics, with an extraordinarily soft and silky weave.

Karnak Menoufi

This ancient Egyptian cotton, which is extremely beautiful and rare, is a native variety of the coastal area between the lakes Burullus and Manzala.
This dark cotton was found in the Nile delta, the symbol of fertility, where it seems almost pulled out of the mud and soaked in the miraculous silt.
This is not a periodic gift of nature, but a harvest and an exceptional event that occurs only with the right combination of agroclimatic conditions: on lands that have unique bio-chemical features and with regular exposure to the sun and saltwater breezes from the lakes and the nearby sea.
For decades no cotton producer could cultivate this variety. What was once considered as a lost botanical treasure and the touchstone of spinning of the past, has today found new life.
Its natural cream-coloured fiber has a long staple which makes it spinnable in ranges of ultra fine counts. Experience and knowhow can give the yarns unparalleled strength, a soft weave with maximum versatility. The mercerization enhances the natural luster, emitting a very special pearly and iridescent light. The excellence of the processing and manufacture procedures can produce truly unique garments, for real connoisseurs of textile quality.

Measuring the fibers

A micronaire is the main measurement unit of the cotton fibers. A micronaire is based on the resistance to pressure of a flow of air passing through a mass of cotton fibers in a sample weighing 3.24 grams and a fixed volume.
An indicator measures the pressure in the tube and gives the value of micrograms per inch.
In other words, the permeability of the air is indicative of fineness, because the finer the fibers, the smaller and more numerous are the gaps between them and consequently the higher the resistance to the passage of air.
A finer fiber therefore corresponds to a lower micronaire value. Low micronaire is also a sign of maturity of the cotton, given the same type of cotton, the immature fibers, which are more empty and light, are in greater numbers in the sample, and thus lower values are recorded.

The thread count

The count indicates the fineness of the yarn itself. There are very many ways to measure the count. Currently the most widely used is the metric count Nm, which indicates the number of kilometers of thread that are obtained with one kilogram of fiber.
Nm 260 therefore means that 260,000 meters of thread weigh one kilo. So 1/260 means a single thread with a count of Nm 260. On the other hand, 2/260 means a 2-ply thread, obtained from two Nm 260 threads.