Echinochloa

Echinochloa is a grass genus, some of whose members are millets grown as cereal or fodder crops. The most notable of these are Japanese Millet (E. esculenta) in East Asia, Indian barnyard Millet (E. frumentacea) in South Asia and Burgu Millet (E. stagnina) in West Africa. Collectively the members of this genus are called barnyard grasses (though this may also refer to E. crus-galli specifically), barnyard millets or billion-dollar grasses.

When not grown on purpose, these grasses may become a very large nuisance to farmers. In particular Common Barnyard Grass (E. crus-galli) is notorious in this regard; it is not easily suppressed by living mulch such as Velvet Bean (Mucuna pruriens vat. utilis). Early Barnyard Grass (E. oryzoides) is a well-known example of Vavilovian mimicry: the plants have evolved to resemble rice (Oryza), enabling them to escape weeding more easily .

Among the plant pathogens that affect this genus are the sac fungus Cochliobolus sativus – which has been noted on Common Barnyard Grass – and rice hoja blanca virus. Both affect many other grass species, in particular most important cereals, and Echinochloa weeds may serve as a reservoir. The fungi Drechslera monoceras and Exserohilum monoceras have been evaluated with some success as potential biocontrol agents of Common Barnyard Grass in rice fields; more research is necessary however because they too may not be host specific enough to be of practical use.