Echinochloa spp. in Australian rice fields'species distribution and resistance status

Six Echinochloa species, i.e. barnyard grass (Echinochloa crus-galli (L.) Beauv.), awnless barnyard grass(E. colona (L.) Link), hairy millet (E. oryzoides (Ard.) Fritsch), prickly barnyard grass (E. microstachya (Wieg.) Rydb),Japanese millet (E. esculenta (A Br.)HScholz), and channel millet (E. inundata Michael et Vickery), were detected in surveysof Australian ricefields in south-eastern Australia. Differences were detected in the rate of germination of species and thismayaffect the efficacy of herbicide treatments where mixes of species occur.Phenotypic variation within E. crus-galli, such as size of panicles, size of spikelets, and degree of awning, sometimesmakes identification difficult and may have implications for seed growers.No instances of herbicide resistance were found in any Echinochloa species despite its widespread occurrence in othercountries.