Echinochloa colonum (L.) Link

Echinochloa colonum germinates during the rainy season or when water levels are on the rise and dies out during the dry season. The flowering starts 3 or 4 weeks after germination, quickly followed by fructification and the first seeds come to maturity 45 days later.

Northern Cameroon: In rainfall cultivation during the rainy season, Echinochloa colona is a species mainly present in the middle and end of the crop cycle. It germinates in June or July when the soil has accumulated a large water reserve and regardless of tillage. Cultural operations such as weeding and ridging are followed by new emergence. Flowering occurs after three to four weeks of vegetation, quickly followed by fructification. The first seeds ripen 45 days after germination. Fruiting extends to the drying of the plant early in the dry season (October-November), when the soil becomes too dry. In the temporarily flooded plots, germination takes place as soon as the plot is dried. The development of the plant takes place as long as the soil remains moist.
Mayotte: Echinochloa colona flowers and fruits all year round.

Echinochloa colonum is an annual species. It multiplies by seeds. An individual can produce several thousand seeds.

Distinction of Echinochloa species is not easy

Distinctivve criteria of several Echinochloa species

Echinochloa colonum does not have any particular climatic preference in the tropical region, provided that the ground is very wet even temporarily flooded. It is adapted to sun or light shade and grows on soils rich in humus, in vase or in clay. It is found in sewers and edges of channels, short grass, cultivated land, whether in dry or marshy areas. This plant is one of the worst weeds in rice fields, in wet conditions. It occurs most often in low latitude, but we can meet it at 2000 m altitude.

Northern Cameroon: Echinochloa colonum is characteristic of clay soils and very wet soils like vertisols, recent alluvium along streams, the planosols and lowland areas. This species is common and sometimes abundant, during the offseason, in temporarily flooded plots.
Comoros: absent.
Madagascar: very common weed species in Madagascar, it invades wet sites or temporarily flooded: alluvial plains or small depressions of vertisols or of ferruginous hydromorphic soils, in shallow, in fallows or crop fields.
Mauritius: Uncommon species, it is found in swampy stations.
Mayotte: Echinochloa colonum is an exotic species, very common in a wide range of environments in the hygrophilic region. It grows in disturbed areas such as crops, pastures, gardens, villages, embankments, stream banks and forest trails.
Reunion: Species present in shallow humid zones, temporarily flooded
Seychelles: Species present in vegetable crops.
West Indies: Echinochloa colonum is an exotic species. It is not very demanding in terms of climatic conditions, but it has a particular preference for clayey, humid and temporarily flooded soils. It therefore becomes more abundant during the rainy season and on regularly irrigated plots. Mechanical weeding techniques favour its establishment.

Global harmfulness

Echinochloa colonum is an important crop weed throughtout the tropics and subtropics and has become one of the world's most serious grass weeds (Holm et al 1991; Rao et al 2007). It is an important weed not only of rice crop but also sugarcane, cotton, maize, etc. It is mostly present at the middle and at the end of cultural cycle. Because it resembles rice in the seedling stage it is sometimes transplanted into the fields with the crop. This weed is an excellent competitor and if rice culture is badly managed the crop may be forced out by increasing numbers of this weedy plant. This weed is also an alternate host of diseases, insects, and nematodes (Holm et al. 1991).


Local harmfulness

Benin: Echinochloa colonum is frequent and generally abundant in rice crops.
Burkina Faso: Frequent and usually abundant.
Northern Cameroon: E. colonum is a minor weed of rainfed crops such as cotton, maize, sorghum and groundnuts, as they do not grow well on very moist soils. However, E. colonum is a major weed in irrigated rice cultivations and lowland rice. At seedling stage, it is difficult to discern them from a rice seedling, making the manual control difficult. When the distinction becomes possible, the damage is already significant on culture as E. colona has a very high growth and competition rate in the seedling stage. This species also invade off season sorghum crops on temporarily flooded plots.
Chad: rare but abundant when present.
Comoros: absent.
Ivory Coast: common and generally abundant.
Ghana: frequent and generally abundant.
Kenya: frequent and generally abundant.
Laos: E. colonum is a weed not only of rice but also sugarcane, cotton, maize, etc. It is especially present in the middle and at the end of the crop cycle. Because of its similarity to the rice seedlings, it is sometimes even transplanted in rice fields. This is an excellent competitor and if rice culture is not well managed, the crop can be destroyed by the impressive number of this weed.
Madagascar: low to medium frequency Species (by region) but locally abundant, it can be very harmful to upland rice crops (rice or lowland without water control), cotton, corn because of its rapid growth.
Mali: frequent and generally abundant.
Mauritius: quite rare weed in crops.
Mayotte: Echinochloa colonum is a relatively frequent weed, it is present in 6% of cultivated plots, especially in vegetable crops. It is mainly present in the north of the island.
Nigeria: frequent and generally abundant.
Reunion: E. colonum is not present in crops.
Senegal: frequent and generally abundant.
Seychelles: Species rare but locally abundant.
Tanzania: frequent and generally abundant.
Uganda: Frequent and usually abundant.
West Indies: Echinochloa colonum is a frequent but not very damaging weed in sugarcane, banana, fruit and vegetable crops. However, in some irrigated vegetable crops, it is locally abundant and can become a nuisance.

Echinochloa colonum is a host plant for Pyricularia sp. and Meloidogyne incognita (Kofoid & White) Chitwood. It also hosts various viruses.

Food: Echinochloa colonum is often used in times of food shortage as a famine food. In Chad (central) and Sudan (Kordofan, Darfur) the seeds of this plant are ground into flour from which porridge or bread can be prepared. In Rajasthan in India the seeds are used as rice - hence its English common name of 'jungle rice', from the Hindustani jangal, meaning wild. Indian barnyard millet (Echinochloa frumentacea), a cultivated crop in India, was domesticated from E. colona.

Livestock feed: In Madagascar, Echinochloa species are often quite good fodder.
 

Global control

Cultural control: The cultivation in the early stages of development can overcome this weed. Manual control in the early stages is difficult.
Biological control: In Japan, a pathogen Exserohilum monoceras was tested as bio-herbicide against Echinochloa species in rice. In the Philippines, Exserohilum monoceras kills seedlings E. colona but not rice.
Chemical Control: Echinochloa colonum may be removed by an application of butachlor to 1.5 kg / ha, of anilophos to 400 g / ha, pretilachlor to 1.0 kg / ha or Pendimethalin 1.5 kg / ha before germination.
 
For annual grass weed control tips irrigated rice and lowland in Africa, visit: http://portal.wiktrop.org/document/show/32
 
Local control

Madagascar: Manual weeding of Echinochloa spp. is very difficult because young plants are very difficult to differentiate from rice seedlings. Weeding favors lifting. The echinochloas are plants that support well the flooding. Chemically, possible control with oxadiazon, alachlor and diuron on pre-emergence or with fenoxaprop-ethyl postemergence on young plants. Good control by glyphosate, even on older plants.
 

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