Euphorbia heterophylla L.

Code

EPHHL

Growth form

broadleaf

Biological cycle

annual

Habitat

terrestrial

Northern Cameroon: Germination of Euphorbia heterophylla occurs during the first heavy rain and extends throughout the rainy season. It is strongly favored by tillage (plowing, weeding, hilling). The complete cycle, from germination to seed production, lasts from 45 to 50 days, which gives this species the opportunity to perform several cycles during the same growing season and gives it a high capacity of multiplication and infestation.
Côte d'Ivoire: In the cotton area, germination of Euphorbia heterophylla takes place from March to October.

Euphorbia heterophylla is a C4 species.

Euphorbia heterophylla can be found from sea level to nearly 1,400 m (3,281 ft) elevation, but it is only a serious weed in warm climates. It is found in cultivated crops (Rice, soybeans, cowpeas, corn and sugarcane), vegetables, pastures and wastelands. Plants grow rapidly and often shade out seedlings of crops.

Northern Cameroon: Euphorbia heterophylla is a ruderal species, very nitrophilous. It grows in regions where rainfall is above 1100 mm, in well structured and fertile soils (alluvial ferruginous fersialitic).
Comoros: This species grows in dry environments as well as in humid environment of the three islands, up to 800 m altitude.
Côte d'Ivoire: Euphorbia heterophylla is a common species in open environments without excessive shading. It is a weed of all annual and perennial crops and pastures.
French Guiana: Common species of ruderal areas on sandy soil.
Madagascar: recently introduced species, little known, very localized and minimally intrusive.
Mauritius: A weed of crops, of uncultivated areas and river banks at low altitude.
Reunion: This species is found in many ecological situations, on the well-structured, fertile and well-drained soils. It needs sun and grows both in dry areas and in wetlands.
Seychelles: Species of fallows and abandoned places. It is rarely abundant.
West Indies: Euphorbia heterophylla is a indigenous species. It grows on both clayey and poorly developed soils (soils on ash, andosoils, etc.). It is strongly favoured by tillage (ploughing, weeding...) and chemical weeding.

Euphorbia heterophylla is a host plant for several viruses of crops such as Euphorbia mosaic virus (Begomovirus), tomato yellow leaf curl virus (Begomovirus) and mungbean yellow mosaic virus (Begomovirus).

Toxicity : Euphorbia heterophylla can be toxic for livestock.

Global harmfulness

Euphorbia heterophylla is a common and very competitive weed of upland rice in the savanna zones of Africa. It can rapidly form a closed canopy, and it has a life cycle of only about 60 days from germination to seed setting contributing to a rapid build-up of the population. Seeds of E. heterophylla are dispersed explosively through its dehiscent seed capsules (Wilson, 1981). Germination occurs throughout the cropping season due to the variable dormancy of the seeds. E. heterophylla is particularly problematic in mechanized cropping systems as contamination of fields frequently occurs through machinery; other sources of infestation are seed supply and wild animals (Johnson, 1997). It can develop into monocultures, especially with regard to competitive crops such as soybean, cowpea and cotton. E. heterophylla was one of the species that was observed to increase with duration of rice cropping after fallow in C?te d'Ivoire (Johnson and Kent, 2002).It can complete life-cycle within 80 days. The weed can completely cover a soybean crop within 2 to 3 weeks after emergence. The latex is toxic.

Local harmfulness

West Africa: It is locally abundant in West Africa (Ivory Coast, southern Togo, Southern Nigeria) where it can develop into monospecific stands, particularly competitive with regard to crops such as soybean, cowpea and cotton. It is insensitive to pre-emergence herbicides currently used for cotton, soybean and cowpea. Repeated use of these products promotes this species. However, it is sensitive to anticotyledons pre-emergence herbicides of corn. Minor species in northern Cameroon, it is a major regional species in Ivory coast.
Benin: frequent and generally abundant.
Burkina Faso: frequent and scarce.
Northern Cameroon: Euphorbia heterophylla is rare and scarce.
Chad: frequent and scarce.
Comoros: ruderal species without particularly harmfulness, it is used as an ornamental plant in the yards of homes.
Ivory Coast: common and generally abundant. In cotton crop, it is strongly dominant in the areas of Boundiali, Daloa, Dianra, Diawala, Dicodougou, Kani, Kasséré, Koni, M'Bingué, Morondo, Niélé, Niofoin, Séguela, Sinématiali, Yamoussoukro.
Ghana: rare and scarce.
French Guiana: Very frequent species on the dikes along the edges of rice paddies. It is also very common in orchards and not very common in vegetable areas. Its growth and rapid seed production allow it to be selected by repeated chemical weeding (notably with glyphosate). This is why it can be abundant in citrus orchards or chemically weeded pineapple plots.
Kenya: frequent and scarce.
Madagascar: Little known as a weed of crops. It was only encountered as a weed in the Midwest (only 10 plots of 330) and around Antananarivo as ruderal plant.
Mali: frequent and scarce.
Mauritius: A weed fairly common in dry areas, with an average harmfulness.
Uganda: Rare but abondant when present
Reunion: E. heterophylla is a weed present in 25% of cultivated land, with an invasive characteristic. Its development cycle is very fast (it can produce seeds 45 days after emergence and so do several cycles in a year). It is frequently found in fields of young canes where its cover may reach 70-85%, but also in vegetables.
Senegal: rare and scarce.
Seychelles: A weed of low harmfulness.
South Africa: It is distributed to the North East of South Africa.
Tanzania: frequent and usually abundant.
West Indies: It is one of the most frequent weeds in agricultural areas where it is most often found in regions with rainfall above 1000 mm and in regularly irrigated plots. It is present in all crops. It is a short-cycle plant with a high infestation capacity. It is more damaging in vegetable and fruit crops. Under certain conditions, it forms monospecific stands that often require more frequent weeding operations.

 

Global control
 
For weeding Advice for broadleaf annual weeds of irrigated rice and lowland in Africa, visit: http://portal.wiktrop.org/document/show/19

Local control

Côte d'Ivoire: A large and repeated use of certain herbicides such as glyphosate in some farms translates or can result in evolutions of flora and the selection of certain species like Euphorbia heterophylla that becomes very difficult to manage, but which is now controlled by trifloxysulfuron-sodium herbicide.
In cotton crop, Euphorbia heterophylla is not controlled by the pre-emergence herbicides popularized. Two active ingredients allow a good control of this weed (oxadiargyl and trifloxysulfuron). Similarly, post-emergence treatment of weeds and pre-emergence treatment of cotton and directed treatment with shield are effective means of control.
- Pre-emergence treatment of weeds and cotton: on clean soil, the day of sowing or the day after, apply with a backpack sprayer oxadiargyl at 240g a.i./ha
- Post emergence treatment of weeds and cotton: 15 to 21 days after sowing cotton, apply with a backpack sprayer trifloxysulfuron at 11g a.i./ha
- Post emergence treatment of weeds and pre-emergence of cotton: Sow cotton in a lightly weeded field. The day of sowing or the day after apply with a backpack sprayer an authorized systemic total herbicide (glyphosate at 1440 g a.i./ha or sulfosate at 1920 g a.i./ha) to which may or may not be associated a pre-emergence herbicide such as s-metolachlor + prometryn.
- Directed treatment with a shield: In post-emergence of weeds and cotton, apply with a backpack sprayer equipped with a shield and only in the row (without touching the cotton) an authorized systemic total herbicide such as glyphosate.

Reunion Island:

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