Regulations (pertaining to the Great Lakes region)
In Minnesota, E. crus-galli is considered to pose a “minimal” threat to ecosystems: poses insignificant competition with native species, may naturalize, alters ecosystems insignificantly, and has little possibility of spread within or to other sites (Minnesota Invasive Species Advisory Council 2009).
In 2003, the Great Lakes Indian Fish and Wildlife Commission (GLIFWC) reported that E. crus-galli has widespread established populations, limited effective control methods, and causes low to moderate ecological impacts; as a result, GLIFWC does not require its regulation (Falck and Garske 2003).
Note: Check federal, state/provincial, and local regulations for the most up-to-date information.
Control
Biological
The fungal pathogen Exserohilum monoceras has shown some success in controlling barnyard grass (Catindig et al. 2009).
Physical
Echinochloa crus-galli seeds need to be near the surface to germinate; less than 1 cm of soil will inhibit germination (Adamus et al. 2001). Shallow tillage repeated during the spring can reduce emergence of barnyard grass (OLA and MAFF 2002). Mowing is unlikely to be effective because it will stimulate new growth from lateral buds (OLA and MAFF 2002).
Placing mulch over areas where E. crus-galli is expected to emerge will keep the soil cool and help suppress germination (Cornell University 2012). Further control methods may be needed.
Chemical
There is a high amount of genetic variation among E. crus-galli communities. Managers who choose a chemical control method may need to adjust the compound/application rate to fit the needs of the site (Altop and Mennan 2011). Mature plants show little sensitivity to herbicides applications. Herbicides applied pre-emergence or shortly after emergence typically exhibit the most effective control (Ahmadi et al. 1980, Maun and Barrett 1986, OLA and MAFF 2002).
Barnyard grass is susceptible to sulfometuron methyl (Oust XP®, Spyder®), clethodium (Select MAX®, Intensity®), glyphosate (Accord®, Foresters’ Glypro®, Roundup®, Cornerstone®, Razor®), imazapyr (Aresenal AC®, Habitat®, Chopper®), linuron (Linex 4L®, Loroz DF®), norflurazon (Predict®), sethoxydim (Sethoxydim E-Pro®, Poast Plus®). It is also susceptible to simazine (Simazine 4L®, Simazine 90 DF®), fluazifop (Fusilade DX®), hexainon (Velpar®), pendimethalin (Pendulum 3.3 EC®); however it should be noted that these herbicides cannot be used in Forest Sustainability Certified Areas (Division of Forestry 2011, Keely and Thullen 1991).
Ahmadi et al. (1980) found that when applied to barnyard grass 5 cm in height, glyphosate, terbuthryn, paraquat, atrazine and buthidazole all resulted in 100% control. The efficacy of herbicides containing glyphosate was increased when applied when soil was moist, because it allowed for better translocation through the entire plant (Ahmadi et al. 1980). Glyphosate plus 2,4-D will also control E. crus-galli; it is most effective when applied 6 days after the last irrigation or rainfall (Wicks and Hanson 1995).
Haloxyfop, fluazifop, and sethoxydim offer effective control of (Balyan and Malik 1989). Seedling growth of E. crus-galli can be effectively reduced by applying fluazifop and haloxyfop (separately) to the soil (Kells et al. 1986).
Ammonium salt of imazapic (Plateau®) is effective at controlling barnyard grass (BASF Corporation 2011).
Diclofop was effective at controlling barnyard grass, especially when applied postemergence to plants with less than 4 leaves (West et al. 1980).
2,4-D sodium (Hormicide®) applied pre-emergence will help prevent barnyard from growing. Young plants can be controlled with paraquat, where as more mature plants can be controlled with 2.2-DPA. In Australia E. crus-galli plants treated with F-34 (3,4 - dichloropropionanilide) 2-3 weeks post-emergence were successfully controlled (FAO 2012).
Bispyribac is a postemergent herbicide that is registered for grasses in rice fields and offers effective control of E. crus-galli. Its efficacy may be increased when used in combination with a spray adjuvant and/or urea ammonium nitrate (Koger et al. 2007).
Postemergent treatment with propanil and pendimenthalin offers good control of barnyard grass (Setre Chemical Company 1986). Propanil is most effective against barnyard grass applied before the plants have three leaves (Snipes and Street 1987). However, barnyard grass can become resistant to propanil and resistant communities have been reported in Arkansas (Gealy et al. 2003).
DPX-79406 (1:1 premix of nicosulfuron and rimsulfuron) and rimsulfuron are registered for use in Ontario and offer good control of barnyard grass growing intermingled with corn (Bosnic and Swanton 1997). When applied post-emergence, Rimsulfuron plus thifensulforn resulted in 97% control (Krausz et al. 2000).
Cyhalofop-butyl offers good control of E. crus-galli when applied early postemergence. When applied to barnyard grass growing within rice, this compound had only slight effects on rice quantity and quality (Ntanos et al. 2000). The ethyl ester of fenoxaprop will control E. crus-galli and most varieties of rice are tolerant (Snipes and Street 1987).
For more specific information on chemical control methods, please visit:
Cornell University’s Pesticide Management Education Program: http://pmep.cce.cornell.edu/
Pacific Northwest Weed Management Handbook: http://pnwhandbooks.org/weed/
The Rice Knowledge Bank: http://www.knowledgebank.irri.org/ipm/the-dirty-dozen.html
Other
Ongoing research indicates that E. crus-galli may be susceptible to various natural, biodegradable herbicides derived from microorganisms and from other plant species (Khanh et al. 2006, Li et al. 2012a, Malik 1997, Kato-Nogucki et al. 2012).
Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.