Eradication or mitigation? How to manage patches of glyphosate resistant Echinochloa colona.

Abstract

Glyphosate-resistant Echinochloa colona L. is a common weed in non-irrigated cotton systems. E. colona is a small-seeded species that is not wind-blown and has a relatively short seed bank life. These characteristics make it a potential candidate to attempt to eradicate resistant populations when they are detected. A long-term systems experiment was developed to determine the feasibility of eradicating glyphosate resistant populations using different tactics under field conditions. The glyphosate only treatment had consistently higher emergences and plants remaining throughout the four-year experiment. In this experiment, the BMP treatment which contained two non-glyphosate tactics in crop and fallow were shown to be effective at managing glyphosate resistant E. colona populations. Treatments that included additional eradication tactics were significantly better at times, however this was not always the case. It is recommended that the BMP (2+2) approach should be used as a baseline combined with monitoring, so that additional eradication tactics can be included as required.