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Avena fatua in fruit (Photo: Barry Rice, sarracenia.com, Bugwood.org)
Avena fatua plants in seed (Photo: Utah State University Archive, Utah State University, Bugwood.org)
Avena fatua plant in seed (Photo: Steve Dewey, Utah State University, Bugwood.org)
Avena fatua leaf sheath and collar (Photo: Richard Old, XID Services, Inc., Bugwood.org)
Avena fatua seed (Photo: Steve Dewey, Utah State University, Bugwood.org)
Avena fatua seed (Photo: Cesar Calderon, USDA APHIS PPQ, Bugwood.org)
Avena fatua infestation (Photo: Steve Dewey, Utah State University, Bugwood.org)
Avena fatua infestation (Photo: Jan Samanek, State Phytosanitary Administration, Bugwood.org)
Anelytrum avenaceum Hack.; Avena fatua var. glabrata Peterm.; Avena fatua var. intermedia Hartman; Avena fatua var. intermedia Husn.; Avena fatua var. intermedia Vasc.; Avena fatua ssp. meridionalis Malzev; Avena fatua var. vilis (Wallr.) Hausskn.; Avena fatua var. vilis (Wallr.) Malzev; Avena intermedia Lindgr.; Avena intermedia T. Lestib.; Avena lanuginosa Gilib.; Avena meridionalis (Malzev) Roshev.; Avena patens St.-Lag.; Avena pilosa Scop.; Avena sativa var. fatua (L.) Fiori; Avena sativa var. sericea Hook. f.; Avena septentrionalis Malzev; Avena vilisWallr.
Common wild oat, wild oat
Native to the Mediterranean. Ethiopia, N. Africa, Europe and Asia among other locations
Avena fatua is naturalised in many parts of the world where cereals are grown in Africa, Europe and Asia among other locations.
Avena fatua is found in the highlands of the three East African countries (Terry and Michieka, 1987) and in Kenya has been recorded in wheat growing areas in Rift Valley and Central provinces.
Leaf blades are flat, about 10-45 cm long and 3-15 mm wide with the membranous small structure at the junction of the leaf sheath and leaf blade (ligules) up to 6 mm long. The long dark green leaves are rough due to small hairs. The youngest leaf is rolled up.
The inflorescence of Avena fatua is a loose, open panicle with 2-3-flowered stalked (pedicelled) spikelets. The panicle is 10-40 cm long and up to 20 cm wide with spreading branches and the spikelets hanging from long stalks (pedicels). Each of the 2-3 florets has an oval abscission scar at its base, causing them to fall separately.
Avena fatua is spread as a contaminant of cereal seed, by people, by farm animals and through contaminated shared farm implements. The seedlings are also hairy. The awn of the A. fatua seed twists into a helix on drying and untwists when wet, thereby drilling the seed into the soil.
Plants in the genus Avena resemble wheat (Triticum spp.) when growing; only obviously differing from wheat upon maturity when its ears hang downwards, while mature wheat ears face upwards.
Avena fatua is palatable and has medicinal uses but its benefits are outweighed by its negative impacts.
Avena fatua is considered to be one of the world's worst agricultural weeds and it is increasing in importance (CABI Crop Compendium 2011). It is an especially serious weed in grain crops such as barley and wheat. A fatua invades and lowers the quality of a field crop, typically wheat or oat fields and competes for resources with the crops. It causes soil dryness and provides favourable conditions for diseases and pests (e.g. frit fly, nematodes and smut).
The precise management measures adopted for any plant invasion will depend upon factors such as the terrain, the cost and availability of labour, the severity of the infestation and the presence of other invasive species. Some components of an integrated management approach are introduced below.
The best form of invasive species management is prevention. As Avena fatua is so widespread this is unlikely to be possible in many instances. If prevention is no longer possible, it is best to treat the weed infestations when they are small to prevent them from establishing (early detection and rapid response). Controlling the weed before it seeds will reduce future problems. Control is generally best applied to the least infested areas before dense infestations are tackled. Consistent follow-up work is required for sustainable management.
There are effective nonchemical methods for controlling A. fatua through soil cultivation and crop rotation.
When it is a weed of cereal crops such as wheat, oats, barley it is difficult to distinguish A. fatua from the crop until flowering. Therefore, the wild oat should only be removed after flowering. Because A. fatua seeds can stay dormant in the soil up to 10 years, it is important to remove plants before they produce seed. A. fatua seeds should be removed before milling to ensure good grain quality. A controlled burn after harvest can reduce the viability of the A. fatua seeds that remain on the soil surface. Many selective herbicides can be effective alone, in mixtures or sequences. Correct timing and rate of herbicide application is critical to maximise control. When using any herbicide always read the label first and follow all instructions and safety requirements. If in doubt consult an expert.
Careful cleaning of sowing material can reduce A. fatua infestations.
In Kenya Avena fatua is declared a noxious weed of Agriculture under the Noxious Weeds Act CAP 325, in Kenya. Accordingly the Minister of Agriculture can compel land owners who have such declared noxious weeds growing on their land to eradicate or have it otherwise removed. However, it is not declared in Uganda and Tanzania.
Members of the tribe Aveneae (oats) have glumes that are larger than the lemma and that remain on the panicle inflorescence after the grains shatter (persistent glumes). As a specific trait of Avena species, the lemmas end in 2 small teeth and have 2-3 awns arising from the back which are mostly dark-coloured, bent and 3-4 cm long.
Bayer Crop Science. Weedspotter - wild oat and winter oat. www.weedfocus.com/content.weedspotter/ 244/1036/e-Tools/e-Tools/Weedspotter.mspx. Accessed February 2011.
CABI Crop Compendium online data sheet. Avena fatua. CABI Publishing 2011. www.cabi.org/CPC. Accessed March 2011.
Government of Kenya (1983). The Suppression of Noxious Weeds Act: CAP 325 of the Laws of Kenya. 2nd Ed. Government Printer, Nairobi, 5 pp.
Ibrahim, K. M and Kabuye, C.H.S. (1987) An Illustrated manual of Kenya grasses, FAO, Rome.
Terry, P.J. and Michieka, R.W. (1987). Common weeds of East Africa/Maguga ya Africka Masharaiki. FAO, Rome, 184pp.
Wikipedia contributors. "Avena fatua L. " Wikipedia, The Free Encyclopedia en.wikipedia.org/wiki/Avena_fatua. Accessed February 2011.
Agnes Lusweti, National Museums of Kenya; Emily Wabuyele, National Museums of Kenya, Paul Ssegawa, Makerere University; John Mauremootoo, BioNET-INTERNATIONAL Secretariat - UK.
This fact sheet is adapted from The Environmental Weeds of Australia by Sheldon Navie and Steve Adkins, Centre for Biological Information Technology, University of Queensland. We recognise the support from the National Museums of Kenya, Tropical Pesticides Research Institute (TPRI) - Tanzania and Makerere University, Uganda. This activity was undertaken as part of the BioNET-EAFRINET UVIMA Project (Taxonomy for Development in East Africa).
BioNET-EAFRINET Regional Coordinator: firstname.lastname@example.org