Wild oats are a kind of grass weed and one of the greatest enemies of certain grains such as barley, rye and wheat.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/growth-wheat-weed-can-be-predicted-reduce-use-herbicides
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/science-daily
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/agriculture
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/herbicide
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/wheat
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/environment
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/weeds