Setaria pumila (Poir.) Roem. & Schult.

Northern Cameroon: The germination of Setaria pumila takes place in June when rains are abundant and the soil is humid. The germination period is short (2-3 weeks), but few new emergences may appear after weeding and mounding. The vegetative growth period is short. Flowering occurs as from the month of July, after four weeks of vegetation, and extends up to the end of September. Individuals that emerge late have reduced flowering period. Fruiting and dissemination extend up to the drying of the plant at the beginning of the dry season (November), where soil moisture decreases. In the temporarily flooded areas, S. pumila development cycle is shifted and takes place during the period of the dewatered of the parcel until the drying of the soil.

Distinctive criteria of different Setaria spp.

 

Grows in disturbed places, including gardens, cultivated areas, old lands and along the side of roads, especially where additional water collects in the rainy season. In East Africa they are common and widespread in arable and waste land at all altitude, often becoming very conspicuous in area newly cleared of bush. In West Africa it is a common weed of field crop, waste areas, paths and roadsides. Widespread in the savannah and forest zones. Grows in a wide range of soil types, including disturbed soils, gardens, cultivated areas and old lands.

Northern Cameroon: S. pumila is a species that grows mainly in the Sahelo-Sudanese and Sudano-Sahelian regions where the annual rainfall is between 600 and 1200 mm. It is a ruderal species common along the roads, in the water discharge canals. It grows on the silty clay humid soil such as planosols, the fersialitiques soils and lowland areas on ferruginous soils. In drier Sudano-Sahelian region, it is a species characteristic of vertisols, with high water retention and temporarily flooded areas.
Comoros: common ruderal species, particularly at medium altitude.
Madagascar: ruderal and weed species of dry widespread crops in all climate regions of Madagascar. With Eleusine indica and Digitaria spp., it infests fields near the villages (smoke cultures) and on alluvial plains or in fairly humid lowlands. At altitude, it infests cultivated fields on relatively fertile soils (where volcanic soils of the region of Antsirabe and Itasy).
Mauritius: weed common in cultivated fields of very wet regions, but it can be found elsewhere as well.
Mayotte: Setaria pumila is a cryptogenic species mainly present in the north of the island in secondarized environments of hygrophilic and mesophilic regions.
Reunion: The species prefers the direct sunlight. It loves the warm climate regions with fairly high rainfall and constant humidity. It grows on many soils, sufficiently deep and well fertilized. Related to irrigated crops, it shows a preference for clayey soils. It is very common throughout the humid coastal region of northeast, east and south of the island. In the Western and the Southwest drier region, it operates at an average altitude of around 500-600 m.
Seychelles: Absent.
 

Local harmfulness
 
Burkina Faso: Setaria pumila is rare and scarce in paddy fields.
Northern Cameroon: Setaria pumila is a minor weed although it is present in over 25% of the plots cultivated in Sudano-Sahelian region. Its low tillering and reduced development generally allow easy control during weeding and hilling.
Comoros: A weed common but rarely abundant.
Madagascar: Fairly common in the highlands on the fertile land with low to medium abundance, it can be harmful for upland rice crops, beans and other vegetable crops and forage crops.
Mauritius: A weed of low harmfulness, it is not present in large numbers in the cultures.
Mayotte: Setaria pumila is a rare weed, present only in 1% of cultivated plots, especially in vegetable crops.
Reunion: S. pumila is present in 20% of cultivated land. It colonizes mainly vegetable crops but also the sugar cane fields. The moment it becomes abundant, it is harmful for crops, but not stuffy.
Senegal: Rare but abundant when present in paddy fields.
Seychelles: Absent.
Chad: Frequent and scarce in paddy fields.
 

Livestock feed: Setaria pumila is used as fodder.
Agronomy: In some regions, this grass plays an important role in stabilising bare soil to protect it from erosion.

Control

Mechanical control presents no special problem and chemicals are available which enable the annual Setaria species to be controlled effectively in a variable crop. The following list indicates the range of possibilities: trifluralin can be used as pre-sowing treatment in beans and cotton, alachor or metolachor pre-emergence in maize, pendimethalin pre-or metoxuron early post-emergence in wheat, metribuzin pre-or post-emergence in tomato, asulam post-emergence in sugar cane.

Management recommandations for annual grasses in rice fields: http://portal.wiktrop.org/document/show/32

Global management
Mechanical control: Setaria pumila presents no special problem in the context of mechanical control
Chemical control: Setaria pumila is effectively controlled by various chemicals, such as: pre-plant trifluralin in beans and cotton, alachore or métolachore in post-sowing / pre-emergence in corn, pendimethalin post-sowing / pre-emergence or early post-metoxuron seeding in wheat, metribuzin pre- or post-emergence in tomato, postemergence asulam in sugarcane
 
For annual grass weed control tips irrigated rice and lowland in Africa, visit: http://portal.wikwio.org/document/show/31
 
Local management
 
Madagascar: The control of Setaria is difficult by tillage of soil or weeding. Chemically, they are controlled by alachlor, pendimethalin, oxadiazon or diuron preemergence and fenoxaprop-ethyl or fluazifop-butyl postemergence on young plants. Only glyphosate is effective on older plants.
Being annual plants, they are controlled by a permanent cover.
 
Reunion

(the dose are expressed in commercial products) - 2014

Data acquired in Reunion on the effectiveness of herbicides in the sugarcane herbicide 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, appropriations from the fee awarded to diffuse pollution Ecophyto finance the plan.

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