NGN - Stopping seed set of barley grass on the upper Eyre Peninsula

Barley grass (Hordeum glaucum) continues to be the major grass weed in cereal cropping on the upper Eyre Peninsula (EP). Barley grass on the upper EP has been documented to have higher seed dormancy levels than elsewhere in the lower rainfall zone (UOA1904-004SAX). Additionally on the upper EP, there are emerging levels of Group 1 resistance in barley grass, thereby reducing in-crop weed control options. When higher seed dormancy and herbicide resistance co-occur, management of barley grass is extremely challenging. As a result, late season tactics such as crop-topping are vital to reduce seed set. Barley grass seed set in pasture phases is currently poorly controlled and this is a major constraint to cropping enterprises. Effective late season tactics to minimise barley grass seed set need to be demonstrated and communicated locally in the Upper EP. Many of these tactics are well understood, but further refinement, validation and extension activities are required locally to ensure effective implementation of these strategies. This investment will further investigate management tactics that may delay flowering in barley grass making it feasible to spray-top effectively without damaging medic seed set or alternatively to manipulate barley grass emergence to make the flowering window of all cohorts more synchronised. AgCommunicators will assist in the development and delivery of effective communication and extension activities for this project to assist with grower adoption and practice change in management of Barley grass on the upper EP. This investment will demonstrate and validate how different crop and pasture sequences change weed density in mixed-farming system on the upper EP and provide further extension activities for growers to increase confidence to implement recommended management strategies to drive down barley grass populations.