Bidens pilosa L.

Code

BIDPI

Growth form

Broadleaf

Biological cycle

annual

Habitat

terrestrial

Brazil: Bidens pilosa can be found all year round in the southern part of the country, but mainly in spring and summer. The entire cycle can be completed in 150 to 36O days, depending on the time of germination. Individuals germinating between March and July flower after 60 to 70 days, while those germinating in August only flower after 100 days.
Northern Cameroon: In the region of Guinean climate Bidens pilosa may be present throughout the year without marked dry season. However, in the Sudano-Sahelian region, with an average rainfall of 1100 mm and a marked dry season (6 months), it occurs as a weed in annual crops during the mid and end of the agricultural cycle. Germination begins in July after sufficient rainfall has accumulated and when the underground water reserve is full and itlast until August. Flowering begins in October and ends in early November. Fruiting takes place from October to December, until the plant dries out at the start of the dry season.
China: Bidens pilosa flowers and fruits all year round.
Mayotte: B. pilosa flowers and fruits all the year round. It develops more during the rainy season.
Morocco: Bidens pilosa is a recently naturalized exotic species. It is nitrophilous and ruderal, and grows in marshes, ditches, wastelands, gardens and damp crops on plains and low mountains, from 0 to 1,000 m altitude.
New Caledonia: Bidens pilosa seeds are able to germinate immediately after dispersal, at any time of the year, in areas with high rainfall and after rain falls elsewhere. Flowering starts quickly and lasts throughout the warm season. Fruiting lasts until desiccation of the plant during the cool season.
West Indies: Bidens pilosa flowers and fruits almost all year round.

Bidens pilosa is an annual species, reproducing only by seeds. These are spread by humans, animals, water and wind. They cling to clothing or fur and the plant is dispersed in this way from one zone to another. The numerous seeds (3000 to 6000 per individual) are capable of germinating immediately after dispersal. All the species of Bidens produces large quantity of seed, which can germinate immediately after being shed. With B. pilosa it has been shown that, if conditions are not suitable for germination for about 8 weeks, the seed becomes dormant and can remain viable for a considerable period. Besides the competitive effects of the weeds of the crops, their barbed seeds can be troublesome in their ability to adhere to and penetrate the hair of animal, clothing, skin, etc.

Disctinctive criteria between Bidens species

Bidens pilosa tolerates many types of environments but prefers wet zones and heavy soils.

Northern Cameroon: Bidens pilosa is a species occurring in wet areas with annual rainfall greater than 1500 mm. It occurs locally in the drier areas, only in plots where the soil is argillaceous such as vertisols and ferralitic soils with a high capacity of water retention, or in humid lowlands.
China: Bidens pilosa grows along roadsides, in crops and in villages, at altitudes of up to 2,500 m.
Comoros: The species is present in all three islands, up to 1400 m altitude. It prefers humid areas.
Madagascar: Common species in the uplands and wetlands, on relatively fertile lands in lowland or in recently cleared forest plots.
Mauritius: Species widespread in the island. It grows in ruderal and weed of gardens, in agricultural fields, roadsides and unoccupied plots.
Mayotte: Bidens pilosa is a very abundant weed in pineapple and ylang-ylang crops, but also present in vegetable and food crops. It is present in abundance in the rainy zone of the north of the island as well as in the central zone.
Reunion: The species is well adapted to all ecological situations of Reunion, including at altitude up to 1000 m. It occurs indifferently, in all areas and in all agro-ecological contexts of the island.
Seychelles: Species present in all areas, at all elevations.
West Indies: Bidens pilosa is a very ubiquitous species, often occupying wasteland, fallow land and field margins at altitudes of 0 to 900 m.

Global harmfulness

Bidens pilosa is among the 300 major invasive species in the Pacific and Indian Ocean. In Africa, Bidens pilosa is considered as a weed in numerous countries, and it is probably present in all the countries. It is a troublesome weed for more 30 crops in over 40 countries. B. pilosa has allelopathic properties. Leaf and root extracts are known to significantly suppress germination and growth of many plants and are believed to remain active throughout decomposition. Furthermore, B. pilosa grows three times faster than similar plant species. The seeds contaminate seed banks.
Bidens pilosa is a problematic species for many reasons throughought its range. All of these porperties render it a quite formidable competitor. Its thick stands impede access to roads, trails, and recreational areas, are a nuisance to travelers and tourists, and inflict damage to pavements and walls. Its burrs are a nuisance to people, as well as, sheep and other fleece producing livestock. The burrs are also a troublesome seed contaminent as they are difficult to seperate from grain. The roots, leaves, and flowers are strongly phytotoxic and a poisonous, if unprepared, and capable of inflicting injury.

Local harmfulness

Benin: rare and scarce.
Brazil: Bidens plosa infests most annual crops, except winter cereals in the south and irrigated rice. It also infests orchards and other perennial crops. The most heavily infested crop is soya, where yields can be reduced by 30% in the event of heavy infestation.
Burkina Faso: rare and scarce.
Comoros: Bidens pilosa is a weed, very common in young agricultural fields and propagate after clearing of plots.
Ivory Coast: common and generally abundant.
Ghana: rare and scarce.
French Guiana: Rare species in the cultures of French Guiana compared to Bidens cynapiifolia.
Kenya: frequent and scarce.
Madagascar: Quite common species which may be locally abundant and very harmful to poorly maintained agricultural fields: maize, cassava, peanuts. It can also interfere with harvest operations.
Mali: rare and scarce.
Mauritius: A weed with medium to high harmfulness in vegetable cultivations and sugar cane fields, when it grows in large numbers.
Mayotte: B. pilosa is a weed present in 38% of cultivated plots. It is particularly abundant in the Ylang fields.
New Caledonia: Known since the mid 19th century, it is now a weed of agricultural fields, especially common in the western coastal regions and Loyalty islands, where it is found on bare soil, unoccupied land, and in recently abandoned farmlands. It can be troublesome for grazing during fruiting period.
Nigeria: rare and scarce.
South Africa: Distributed to the entire part of South Africa except in the North-West province. Common widespread weed and extremely troublesome in crop fields.
Reunion: This weed invades all agricultural fields. It is very frequent (Fr> 70%) and has an average percentage cover of 15% which can reach 80% in some lentils cultivation. However, it does not represent a significant economic stress in properly maintained plots. In sugar cane culture, certified pre-emergence herbicides are effective.
Senegal: rare and scarce.
Seychelles: major weed in most cultivation, including gardening, orchards and tea plantations.
Tanzania: Frequent and usually abundant.
Tchad: rare and scarce.
Uganda: Frequent and usually abundant. Competition from B. pilosa can reduce harvests of dry beans - Phaseolus vulgaris - by 48%.
West Indies: Bidens pilosa is a weed present in all crops. It is a minor pest in sugarcane. It is not very frequent in fruit and vegetable crops but it can become a nuisance at the end of the cycle if it has not been controlled during the crop.

Bidens pilosa is a host to a parasitic plant Cassytha filiformis L. and for different diseases Cercospora megalapotamica Speg., Uromyces bidenticola and Tomato spoted wilt virus Schlerotinia sclerotiorum. It also hosts nematodes. Meloidogyne sp., Paratylenchulus sp., Pratylenchus minuta Linford., Pratilenchus zeae, Rotylenchus reniformis et Helicotylenchus spp.

Food: Leaves are cooked as vegetables,
Animal feed: It is very appreciated by rabbits and poultry.
Ornamental: Bidens pilosa has been introduced in many regions for agriculture and as an ornamental plant.
Medicinal: The crushed leaves are used as a healing agent. Extracts from the aerial parts of the plant have antitumor properties.

Global management

Mechanical control: Bidens pilosa can be removed by manual weeding or hoeing.
Agricultural control: germination may be prevented by the use of mulch.
Chemical control: different effective pre-emergence herbicide: diuron, bromacil, atrazine, simazine, hexazinone, oryzalin, and ametryn. Post-emergence herbicides: 2,4-D, glyphosate, amitrole, metribuzin and dicamba bentazone and the contact herbicides, diquat and paraquat.
 
Management recommandations for annual broad-leaved weeds in rice fields: http://portal.wiktrop.org/document/show/20
 
Local management

French Guiana : Mechanical control is sufficient in vegetable crops.
New Caledonia: The large stands of B. pilosa contribute to the degradation of grasslands; furthermore, the reproduction and spread of this weed in cultivations should be avoided on a collective scale. It is important to counteract its strong ability of proliferation by preventing it from achieving its fruiting cycle (very short) and by limiting its seed dispersal.  Manual weeding of small colonies before flowering is easy. Rotary cultivation causes branching and therefore should be complemented by application of herbicide on regrowth before flowering (2,4-D). Livestocks having stayed in infested areas should be placed in quarantine, and if not, moving in the un-invaded plots should be avoided.

Madagascar: Manual control of B. pilosa is very demanding in time. Its chemical control is fairly easy and inexpensive: diuron or atrazine preemergence. 2,4-D on glyphosate or young plants, 2,4-D + glyphosate on adult plants. B. pilosa is well controlled by mulching and gradually disappears as seedling under permanent vegetative cover.

Reunion Island:
 

The doses are expressed in commercial products - 2014

Data acquired in Reunion on the effectiveness of herbicides in the context of the sugarcane herbicide network by eRcane Network with funding from the ODEADOM and ONEMA.
Action led by the French Ministry of Agriculture, food and forest, with financial support from the National Agency for Water and Aquatic Environments, on the finance issued from the tax for the pollution diffused, attributed to the finance of the Ecophyto plan.

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