Cyperus esculentus L.

Northern Cameroon: The emergence of young plants of Cyperus esculentus is carried out throughout the humid period of soil. It is favored by weeding, which breaks the dormancy of the tubers by separating them from the mother plant, Flowering is induced by long days and takes place between July and October, 4 to 8 weeks after emergence. Some populations do not flower, especially the cultivated populations. The plants wither at the beginning of the dry season, depending on the drying of the soil. 

Northern Cameroon: Cyperus esculentus is found in all soils with a pH between 5 and 7. This species is usually more abundant on sandy loam alluvial soils along river. It is very tolerant to high soil moisture. It is often associated with C. rotundus, but in the most humid stations, it tends to replace C. rotundus and Cynodon dactylon. It tolerates shade in crop cultivations.
Comoros: ruderal plant that is found mostly in areas exposed to the sun, at low and medium altitude.
Madagascar: Species quite common in dry crops, which settles in relatively rich and moist enough soils, down slope or in the alluvial plains.
Mauritius: A weed of crops, it is found mainly in the wet and cool stations.
Mayotte: C. esculentus is an uncommon weed, which occurs in fruit and vegetable crops in the rainy northern region of the island.
Reunion: rare species but distributed over the entire circumference of the island and can reach up to 1000 m altitude
Seychelles: This species is observed in heavily irrigated crops in wet fields and heavy soils. It tolerates very wet soils, but grows well on all soil types.

Global harmfulness

Tubers and roots being interconnected to each other to a depth of 50 cm (19.68 inch) or more. The tubers are connected by fragile roots that are extremely prone to snapping when pulled on, so it is extremely difficult to remove Cyperus esculentus with its entire root system intact. The plant will regenerate completely if even a single tuber is left in place. Tubers typically survive up to ~ 3-4 years.

Local harmfulness

Benin: frequent and generally abundant.
Burkina Faso: frequent and scarce.
Northern Cameroon: C. esculentus is a local major weed.
Chad: frequent and generally abundant.
Comoros: A weed present in banana plantations, cassava and sugar cane.
Ivory Coast: common and scarce.
Ghana: frequent and generally abundant.
Kenya: Cyperus esculentus is frequent and usually abundant.
Madagascar: A weed of low frequency, but sometimes locally abundant as small spots more or less widespread, especially in corn and bean crops.
Mali: rare but abundant when present.
Mauritius important weed of crops may be highly harmful.
Mayotte: C. esculentus is an infrequent weed, present in 1% of cultivated plots, but can be locally abundant in fruit and vegetable crops.
Nigeria: frequent and generally abundant.
New Caledonia: The species is reported since 1850 and is the main weed in vegetable gardening. It has remarkable plasticity. However environmental factors affect its development, the humidity is therefore essential to its reproduction and growth. Under certain conditions, it can therefore also become an invasive species of degraded or planted forage crops. But it does not tolerate competition for light from other plants and tends to disappear when the vegetation grows. The tubers remain dormant in the soil until the next tillage.
Uganda: common and generally abundant.
Reunion: A weed infrequent, occasionally encountered in arboriculture, sugar cane and especially vegetable cultures because it is favored by rotovator tillage. It develops by multiplication of tubers, leading in certain situations collection, 30-50% of the plot.
Senegal: rare but abundant when present.
Seychelles: serious or principal weed of fruit crops, vegetable and tubers.
Tanzania: frequent and generally abundant.
West Indies: Cyperus esculentus is favoured by shallow cultivation operations, which separate and disperse the tubers. It is not sensitive to pre-emergence herbicides and not very sensitive to post-emergence contact or systemic herbicides. Because of its ability to multiply vegetatively throughout the growing season, this species becomes invasive very quickly.

Food: In Northern Cameroon, Cyperus esculentus is cultivated for its tubers, used in human food. The tuber flour of C. esculentus is a source of carbohydrates and some mineral elements such as iron and calcium.

Global control

Herbarium pictures ReCOLNAT: https://explore.recolnat.org/search/botanique/simplequery=Cyperus%2520esculentus