Cotton
Gossypium hirsutum L.

Order: Malvales

Family: Malvaceae

Names:

Gossypium
Hirsutum
Cotton

Other Names:

American Upland Cotton.

Summary:

A perennial or annual shrub to 1.5 metres tall, with 3-lobed leaves and white to cream flowers that turn purple pink with age and produce seed pods with balls of white fibres. It is grown for cotton fibre, seed and cotton seed oil.

Description:

Cotyledons:

Two. Kidney shaped

Leaves:

Stipules -
Petiole -
Blade - 3 lobes
Stem leaves -

Stems:

Up to 1500 mm tall.

Flower head:

Flowers:

White to cream turning purple.
Ovary -
Sepals -
Petals - White to cream initially and turning pink to purple with age, 30-40 mm long.
Stamens -
Anthers -

Fruit:

Pod with distinctive white balls of woolly fibre.

Seeds:

Have long convoluted hair or lint.

Roots:

Key Characters:

Biology:

Life cycle:

Perennial but treated as an annual when cropped. Seed germinates as soil temperatures rise above 150C and the seedling grows slowly producing flower buds 6-8 weeks after germination. Growth then quickens for 6-8 weeks until "cutting out" when flowering and fruiting stop. The bolls take 50-80 days to mature. The cotton fibres usually reach maximum length within the first 20 days then thicken as cellulose is laid down. The crop is normally planted in October, set fruit in January, ripens in March and is harvested in June. Herbicides are normally used to desiccate the crop when 60% of the bolls have opened. Lint is removed from the seeds by ginning. Long fibres are used for spinning and short fibres for padding. The seed is used for cottonseed oil and meal.

Physiology:

Sensitive to waterlogging.

Reproduction:

By seed.

Flowering times:

Seed Biology and Germination:

Soil temperatures must be higher than 150C for seed to germinate.

Vegetative Propagules:

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

Spread mainly by intentional planting.

Origin and History:

America. Central America.

Distribution:

ACT, NSW, NT, QLD, WA.

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Sub tropical.

Soil:

Well drained.

Plant Associations:

Significance:

Beneficial:

Important fibre crop with fibres that can be spun.
Fodder.
Pulp.
Oils
Hulls used for fuel.
Honey plant.

Detrimental:

Weed of streams, pindan and disturbed areas.

Toxicity:

Cotton seeds and cottonseed meal can be toxic.
Cottonseed meal may contain a toxic compound gossypol, which reduces animal growth rates. Pigs and rabbits are most susceptible then poultry then the ruminants, cattle and sheep are most tolerant.

Symptoms:

Poultry - Seed fed to poultry may cause egg white to turn pink and yolks to mottle and become putty like after storage. Cottonseed meal may cause death, lowered hatchability, discoloured yolks and white and unusual consistency.
Pigs and ruminants - symptoms show after feeding for 4 weeks to 12 months and may include loss of condition, weakness, gasping, frothing at the mouth, blood stained froth and convulsions prior to death 2-6 days later. Mucous membranes may be blue immediately after death.

Treatment:

Keep cottonseed meal to les than 9% of the ration. Feed iron salts. Use alternate feed.

Legislation:

None.

Management and Control:

Thresholds:

Eradication strategies:

Herbicide resistance:

Biological Control:

Related plants:

Cotton (Gossypium herbaceum) - cultivated
Cotton (Gossypium hirsutum) - cultivated
Native Cotton (Gossypium australe)
Sea Island Cotton (Gossypium barbadense) - cultivated
Sturt's Desert Rose (Gossypium sturtianum)
Upland Cotton (Gossypium arboreum) - cultivated
Western Wild Cotton (Gossypium robinsonii)
Gossypium thurberi

Plants of similar appearance:

References:

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney). P515

Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (1997). Western Weeds. A guide to the weeds of Western Australia. (Plant Protection Society of Western Australia, Perth, Western Australia). P174.

Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #602.3.

Reid, R.L. (1990) The Manual of Australian Agriculture. (Butterworths, Sydney). P129-131.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.