Click on images to enlarge
dry ears of Lolium temulentum - Poison darnel (Photo: Amin Jagel)
foliage (Photo: H. Zell, CC BY-SA)
seeds (Photo: Cesar Calderon, USDA APHIS PPQ, Bugwood.org)
flowers (Photo: Joseph M. DiTomaso, University of California - Davis, Bugwood.org)
leaf sheath and collar (Photo: Joseph M. DiTomaso, University of California - Davis, Bugwood.org)
Lolium temulentum L.
Lolium temulentum Bertero ex Steud.
Darnel ryegrass, darnel, poison ryegrass
Countries in the Mediterranean region.
Lolium temulentum usually grows in the same production zones as wheat and is considered a weed. In Kenya, it has been recorded in the wheat growing areas of Rift Valley, Narok. In Tanzania it has been recorded in Morogoro.
Lolium temulentum infests wheat fields and other cultivated land.
Lolium temulentum spreads as a contaminant of wheat seed, by people and by farm animals.
The similarity between wheat and Lolium temulentum is so great that in some regions L. temulentum is referred to as true wheat (Triticum species). L. temulentum and wheat look alike until the ear appears and are distinguished as follows:
Lolium temulentum grass can be used for fodder and for erosion control. However, these uses cannot compensate for this plant's overall negative impacts.
Lolium temulentum is a weed of wheat farmlands. Even a few grains of this plant will adversely affect crop quality. Its seeds are poisonous to people and livestock. It is very difficult to separate the seeds of L. temulentum from those of what and other small grain crops as they are similar in size and weight. L. temulentum can be a host to a variety of crop pests and diseases.
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. 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.
Preventive measures such as sewing clean seed and preventing seed formation are important means of management. Hand weeding can control this species although this is difficult to undertake early because of the resemblance between this weed and the infested wheat crops. Chemical control is possible in barley and other crops from which it is easy to distinguish. When using any herbicide always read the label first and follow all instructions and safety requirements. If in doubt consult an expert.
Lolium temulentum has been declared a noxious weed in Kenya under the Suppression of Noxious Weeds Act (CAP 325). Under this act the Minister of Agriculture, can compel land owners who have such declared noxious weeds growing on their land to remove or have it otherwise removed. However, this species is not declared in Uganda and Tanzania.
In the New testament, in the parable of the Tares in the Gospel of Matthew: "Let both grow together until the harvest: and in the time of harvest I will say to the reapers, Gather ye together first the tares, and bind them in bundles to burn them: but gather the wheat into my barn".
Lolium temulentum is also said to be one of the many ingredients in Mithradate, which is supposed to have been used by Mithridates VI on a daily basis to render him immune to poisoning.
Government of Kenya (1983). The Suppression of Noxious Weeds Act: CAP 325 of the Laws of Kenya. 2nd Ed. Government Printer, Nairobi, 5 pp.
Schardl, C.L., Grossman R.B., Nagabhyru P., Faulkner J.R. and Mallik U.P. (2007). Loline alkaloids: currencies of mutualism. Phytochemistry 68 (7): 980-996.
USDA Plants Profile. Lolium temulentum. The Plants Database. plants.usda.gov/java/profile. National Plant Data Center, National Resources Conservation Service, United States Department of Agriculture, Baton Rouge, Louisiana, USA. Accessed January 2011.
Wikipedia contributors. "Lolium temulentum." Wikipedia, The Free Encyclopedia. Accessed January 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