Effect of foliar herbicides and Nemo® wetter on Aleman Grass (Echinochloa polystachya) in north Queensland, Australia.

Abstract

Aleman grass (Echinochloa polystachya) is a ponded pasture species that has become invasive in wetland areas of north Queensland. It often grows intermingled with Para grass (Urochloa mutica) and Hymenachne (Hymenachne amplexicaulis) and can colonise deeper water than either of those species (Hannan-Jones & Weber, 2016). Aleman grass is locally restricted in Cassowary Coast and Tablelands Regional Councils and is considered a priority invasive plant by Hinchinbrook and Mareeba Councils. We conducted a field trial near Ingham in north Queensland (Lat: 18.70713, Long:146.17411.) to identify effective herbicides for Aleman grass control. The trial tested five herbicides at three application rates each. The wetting agent Nemo® was also tested for its efficacy as a replacement for the aquatic wetter Bonus® which has been withdrawn from the Australian market. The herbicides were applied by land-based application methods (backpack sprayer) with the aim to provide approved land-based herbicide and wetter recommendations for Aleman grass in north Queensland.