Echinochloa crusgalli habit3 - Flickr - Macleay Grass Man

Crop weeds are

weed A weed is a plant considered undesirable in a particular situation, growing where it conflicts with human preferences, needs, or goals.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. Pla ...

s that grow amongst

crop A crop is a plant that can be grown and harvested extensively for profit or subsistence. In other words, a crop is a plant or plant product that is grown for a specific purpose such as food, Fiber, fibre, or fuel. When plants of the same spe ...

s. Despite the potential for some crop weeds to be used as a food source, many can also prove harmful to crops, both directly and indirectly. Crop weeds can inhibit the growth of crops, contaminate harvested crops and often spread rapidly. They can also host crop pests such as

aphid Aphids are small sap-sucking insects in the Taxonomic rank, family Aphididae. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white Eriosomatinae, woolly ...

s, fungal rots and

virus A virus is a submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are ...

es. Cost increases and yield losses occur as a result. '' Striga'', one of the main cereal crop weeds in

Sub-Saharan Africa Sub-Saharan Africa is the area and regions of the continent of Africa that lie south of the Sahara. These include Central Africa, East Africa, Southern Africa, and West Africa. Geopolitically, in addition to the list of sovereign states and ...

, commonly causes yield losses of 40–100% and accounts for around $7 billion in losses annually. Around 100 million hectares of land in Sub-Saharan Africa are affected by ''striga''. Barnyard grass has been identified as a culprit in global

rice Rice is a cereal grain and in its Domestication, domesticated form is the staple food of over half of the world's population, particularly in Asia and Africa. Rice is the seed of the grass species ''Oryza sativa'' (Asian rice)—or, much l ...

yield losses and certain species have been known to

mimic In evolutionary biology, mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. In the simples ...

rice. Examples of crop weeds include chickweed, barnyard grass, dandelion, '' striga'' and '' Japanese knotweed''. A less commonly known crop weed is Abelmoschus ficulneus.

References

{{DEFAULTSORT:Crop Weed Weeds Agricultural pests Crops

See also

References