Fimbristylis dichotoma (L.) Vahl

Growth form

Sedge

Mayotte: Fimbristylis dichotoma flowers and fruits all year round.

Often in moist disturbed areas. Grows in moist places along paths and roads in rainforest.

Comoros: Fimbristylis dichotoma is absent.
Madagascar: F. dichotoma is a weed which mainly settled in irrigated plots or temporarily flooded low-lying parts of floodplains or ferruginous soils in subhumid and semi-arid areas of low altitude (Northwest Plains West and Southwest).
Mauritius: The species is uncommon.
Mayotte: This native species grows in wet places, in particular around lakes, in marshes or hydromorphic grounds, in edge of forest and sometimes in ditches and agricultural zones.
New Caledonia: The species can develop abundantly in wetland pastures, especially on the east coast.
Reunion: typical species of wet lowlands.
Seychelles: absent.
West Indies: Fimbristylis dichotoma is a native species. It occupies a wide range of environments and becomes abundant on flooded or temporarily wet clay soils. Its frequency and abundance decreases on less developed soils on ash. It can be found up to 700 m altitude.

Local harmfulness

Benin: Fimbristylis dichotoma is rare but abundant when present in paddy fields
Burkina Faso: rare and scarce.
Comoros: F. dichotoma is absent.
Ivory Coast: common and scarce.
Madagascar: F. dichotoma has a low frequency, but is a locally abundant species, often forming quite variable population sizes; it is harmful in irrigated cotton crops and maize. Very common in rice fields, it can be abundant and have a significant impact.
New Caledonia: F. dichotoma is not a major weed in the pastures, but it can develop densely in wet pastures, especially on the east coast. Like many non-palatable species, it is the accumulation of these species that can occupy a large part of the pasture, thus decreasing the availability of forage resources.
Mauritius: This species is not present in crops.
Reunion: This species is not present in crops.
Senegal: rare but abundant when present.
Seychelles: absent.
West Indies: Fimbristylis dichotoma is a relatively benign weed and is common in all crops. Its abundance is generally limited by ploughing and chemical, manual and physical weeding techniques. It frequently constitutes the spontaneous multispecific cover of mechanically weeded fruit crops. Waterlogging of soils due to poor drainage or irrigation systems can rapidly favour its development. It is a plant not much appreciated by livestock (sheep, poultry, etc.) and which, in the context of an integrated system combining plant and animal production, tends to form a thick monospecific plant cover that is difficult to eliminate.

Global control

Directions for management of annual sedges in irrigated rice and lowland in Africa, visit:

Local control

Madagascar: Tillage tends to favor the multiplication of Fimbristylis dichotoma . Weeding or even manual hoeing are very demanding and difficult to drive on time. Pre-emergence herbicides are generally ineffective, except oxadiazon or diuron on certain species. At the early stage, they are quite sensitive to 2,4-D or bentazon. Atmaturity, glyphosate alone is effective. An important vegetation cover delays it generally enough so that the crop dominates it.
New Caledonia: New infestations can be controlled by removing tufts and roots. The best prevention in wetland pastures is to maintain a sufficient herbaceous cover to hinder the germination and development of this hydromorphic species.
 

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