Amaranthus dubius Mart.

Code

AMADU

Growth form

Broadleaf

Biological cycle

Annual

Habitat

terrestrial

French Guiana: Amaranthus dubius has a rapid development, the seeds can be mature only 6 weeks after emergence.

The seeds of Amaranthus dubius can germinate without delay and massively as soon as they fall on the ground.

Amaranthus dubius is an annual species. It reproduces only by seeds, which are dispersed by water and wind. It produces a large number of seeds that have a long viability.

 Keys of Amaranthus

Comoros: Amaranthus dubius grows in ploughed and abandoned land and in the courtyards of houses. It is a plant of low altitude in all region of the island of Grande Comore.
French Guiana : A nitrophilous species common in vegetable crops.
Madagascar: Ruderal species, fairly common in most climatic regions of Madagascar. It grows on soil more or less enriched in organic matter in the surroundings of villages.
Mauritius: weed of crops with a wide distribution.
Nicaragua: Amaranthus dubius is an occasional species, in open areas, especially in anthropised environments, from 400 to 920 m altitude.
Reunion: Species locally well adapted to all ecological situations of Reunion. It is less common on the east coast of the island. Species very nitrophilous, it is abundant on rich soils and in crops with high intake of nitrogen fertilizer, such as vegetable gardening.
Seychelles: Species observed on a wide variety of soil types and textures and at all elevations.
West Indies: Amaranthus dubius is a ruderal species and a crop weed that grows on rich soils, it is sometimes cultivated.

Local harmfulness

Comoros: Amaranthus dubius is a common weed of vegetable crops.
French Guiana: Weed which can be abundant on uncultivated in vegetable crop ridges. Especially during intercroping.
Madagascar: important weed of sheltered cultures including corn.
Mauritius: a major plant pest weed in the vegetable crops. They also compete aggressively with young canes plants when present in large numbers.
Reunion: A. dubius is a weed which has an average ecological amplitude, it is present in 40% of cultivated plots, but not a major agronomic constraints. The average recovery is 7 to 15%. This is a weed rare in sugar cane, it mainly colonizes vegetable crops, in some cases up to recovery cover of over 70%. Rather it is a ruderal species.
Seychelles: A common weed of cultivated fields, gardens and other disturbed and open habitats.
West Indies: Amaranthus dubius is a weed present in all crops. It is a very minor pest in sugarcane but can be abundant in young banana plantations, making it difficult to carry out crop care interventions. It is a common weed in vegetable and food crops where tillage and chemical and organic inputs favour its development.

Local control

West Indies: Amaranthus dubius is easily controlled by various weeding techniques when they are well managed.

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