NGN - Development of management strategies for controlling Phalaris in Northern NSW and Southern QLD

Description: Phalaris is a winter annual grass which was ranked as the 9th most prevalent weed in the Northern region in 2016 (Llewellyn et al. 2016). The current impact of this weed is likely much greater, as in recent years Phalaris has increasingly become a problem weed in the Northern region. The lack of control options was raised as a concern at an NGN meeting in Goondiwindi. Additionally, the presence of populations resistant to some Group 1 and 2 herbicides can limit control options in some paddocks. Identifying the most effective chemical control options as well as cultural control options, such as crop competition, will assist growers in reducing the impact that Phalaris has on grain production.

Outcome: By February 2026, the impact of Phalaris on wheat and chickpea production is reduced through improved grower and adviser understanding of effective management options.

Outputs.

Output 1.

Title: By February 2026, field trials that demonstrate the effectiveness of pre- and post-emergent herbicides and crop competition for control of Phalaris in N-NSW and S-Qld.

Description: Deliverables include:

- Conducting a minimum of 2 field trials in S-QLD (Goondiwindi region) and 2 field trials in N-NSW (North of Narrabri) during both the 2024 and 2025 winter cropping seasons. Each field trial site is to be chosen based on known infestations of Phalaris with significant distribution in the region.

- Field trials are to validate the effectiveness of both pre-emergent and post-emergent herbicides. The treatment list is to be developed in coordination with the GRDC Investment Manager and be limited to registered products. Treatments are to be informed by past research, including from trials conducted by Northern Grower Alliance.

- Field trials will also validate the effectiveness of increased crop competition on control of Phalaris.

- At least one trial in each region is to be conducted in wheat and at least one trial in each region is to be conducted in chickpea.

- Trial reports of each field trial are to be uploaded to GRDC Online Farm Trials.

Output 2.

Title: By February 2026, delivery of extension and communication activities targeted at growers and advisers to increase understanding of management strategies for Phalaris in N-NSW and S-Qld.

Description: Deliverables include:

- Conducting a webinar or similar that communicates effective options for controlling Phalaris populations drawing on results from the project (Output 1) and other knowledge including trial results from Northern Grower Alliance.

- Written content for a Factsheet targeted at growers and advisers covering the results from Output 1. This will be formatted, published and promoted through communication platforms such as GRDC Communications and WeedSmart.

- Hosting of field walks at a minimum of two trial sites per year.

- Be available to provide this knowledge for GRDC Research Updates if requested.

- Be prepared to jointly host a National Grower Network meeting at field day events if requested.