Lepidium didymum L.

Code

COPDI

Growth form

broadleaf

Biological cycle

annual

Habitat

terrestrial

Algeria: Lepidium didymum germinates in autumn-winter and flowers from March to May.

Brazil: Lepidium didymum occurs in autumn, winter and spring. It practically disappears during the summer.
Pakistan: Lepidium didymum flowers from March to June.
West Indies: Lepidium didymum flowers in August.

The leaf shape of Lepidium didymum L. and Ambrosia tenuifolia Spreng. is similar. However, Ambrosia tenuifolia has a generally triangular leaf, whereas the leaf of Lepidium didymum is elongated to oblong.

Algeria: Lepidium didymum is a fairly rare species in the country's vegetable crops. It is also found in ruderal habitats. This species has a preference for clayey-silt soils, fresh, rich in nitrogen. It is an excellent indicator of compacted soils (marks the frequent passage of wheelbarrows or the trampling of ruminants' hooves around watering places, for example).

Lepidium didymum is present on numerous types of soil, usually clayey, wet, compacted or poorly structured. L. didymium is found on roadsides, in grassy forest, in clearings of forest and also as a weed of fields, in East Africa between 1350 - 2800 m above sea level, and everywhere in tropical Africa sometimes also at lower altitudes. It prefers bare, not too dry soil.

Brazil: Lepidium didymum grows in medium-textured soils with good fertility.
Madagascar: Lepidium didymum is a weed species encountered in the Highlands (1000 - 2000 m above sea level) in the fields near rice fields (vegetables, taro, potatoes) of lowland and along the canals and drains.
Mauritius: A weed of crops and plant of fallow and vacant lots, common in humid and very humid regions of the island.
Reunion: The species is very common on the island. It is present in many soils, usually clayey, wet, compacted or poorly structured.
Seychelles: absent.
South Africa: Lepidium didymum thrives in disturbed environments and dry grasslands. It is a weed of crops and open urban areas. 
West Indies: Lepidium didymum is a ruderal species and weed of crops and gardens, at altitudes of 0 to 500 m.

Global harmfulness
 
In some areas, Lepidium didymum is considered a serious weed, eg. wheat, potatoes, peas, carrots and onions in India and onion in Brazil, but in Africa, it does not seem to cause any problems so far. It is a common weed in vegetable crops and around the sugarcane fields. It remains scarce with low harmfulness.
 
Local harmfulness
 
Brazil: Lepidium didymum is an invasive species in vegetable crops and very troublesome in seedbeds. In cultivation it is not very competitive. When present in hay, it gives a bad taste to milk, but in the field it is rarely eaten by livestock.
India: it is a principal weed of potatoes, carrots, lucerne, orchards, peas, sugar beets and wheat. It remains nevertheless little plentiful and weakly harmful.
Madagascar: Lepidium didymum weed is infrequent and not very harmful.
Mauritius: very common weed in crops. It competes weakly with young sugar cane stems but can have a very strong harmfulness in some vegetable crops.
Reunion: It is a weed generally infrequent and sparse in all crops (Fr = 25%). It is much more common in lentils culture (Fr = 40%) and vegetable crops (Fr = 60%) where its low recovery level reach 30-50%.

Algeria: Lepidium didymum is a minor "weed". Not very frequent and not very abundant, it does not generally constitute a nuisance for the crops.

Global control

 Chemical: Lepidium didymum can be controled with herbicides such as 2,4-D applied at 500 g/ha at flowering stage and at one week intervals for five weeks thereafter or metsulfuron at 4 g/ha.

Herbarium pictures ReCOLNAT for Coronopus didymus: https://explore.recolnat.org/search/botanique/simplequery=Coronopus%2520didymus
Herbarium pictures ReCOLNAT for Lepidium didymum : https://explore.recolnat.org/search/botanique/simplequery=Lepidium%2520didymum