Weeds may reduce the aesthetic appeal and palatability of hay and/or may put livestock at risk of toxicity. Despite the challenge weeds pose in cereal crops, they present an alternative opportunity for Australian grain growers to transition into hay production before the grain matures. This strategy not only salvages a potentially compromised crop but also turns a problem into a profit.
Ideally, it’s best to control weeds prior to sowing and during the growing period. When not properly managed, some weeds are undesirable to have in hay, while others are acceptable in hay production. Certain weeds pose a biosecurity risk.
Benefits of Hay in Weed Management
- Diversification of Crop Maturity and Payment: Introducing hay into the rotation diversifies the timing, reducing dependency on a single harvest period, and introduces a profitable break crop.
- Optimisation of Resources: This process also utilises existing machinery and labour more efficiently, spreading workloads across the growing season.
- Risk Reduction: It additionally offers a strategic method to manage herbicide-resistant weeds by removing them before they set seed.
- Cost of Chemical and Application: These costs can be factored into the overall budgeting for crop management.
Planning for Hay Production: Critical Considerations
- Timing and Access to Paddock for Application: This is crucial for effective weed management and hay production.
- Paddock Conditions: Ensure that paddocks are free from residual straw and rocks to maintain hay quality.
- Weed Management: If you know that a certain part of your paddock has weeds in the crop, consider stacking these bales separately after baling.
- Storage and Market Options: Proper storage in accessible sheds enhances hay quality preservation and marketability.
- Labour and Machinery Availability: This availability is critical for timely operations, especially during optimal cutting periods.
- Finance and Marketing: Marketing of hay over a longer period requires strategic financial planning.
Optimal Timing for Hay Production: To prevent weeds like wild oats from negatively impacting hay quality or setting seed, hay paddocks should be cut as near as practical to the wild oats flowering. Timing of cutting may prove difficult due to the need to have the crop heads out of the boot stage if the wild oats have started to flower.
Desiccating Hay Crops: Hay growers now have the option to desiccate hay crops prior to mowing using a herbicide. Desiccating one to eleven days pre-mowing offers the benefits of:
- reducing weed seed set;
- preventing hay and weed re-growth;
- preserving soil moisture; and
- maintaining or improving hay quality.
Before desiccating hay, check that this is an acceptable practice with your hay buyer. For some growers, the wheel tracks from the spray can be an issue for mowing but this is best managed by spraying in a different direction to the hay mower.
Detailed Weed Profiles and Management Strategies:
- Annual Ryegrass: A major threat in southern Australia, showing resistance to multiple herbicide groups, it has little effect on quality cereal hay.
- Wild Oats: This competes aggressively with crops, causing significant grain yield losses. Resistant to major post-emergent herbicides, it also has little effect on quality cereal hay.
- Barley and Brome Grasses: Rapid germinators after rainfall, these grasses can be a major host for diseases, and prolific seed producers. Barley grass seeds are a problem in hay, causing eye injuries to livestock and reduced liveweight gains.
- Turnip Weed: This is known to reduce barley and wheat yields, and to impact livestock products when present in hay.
For a comprehensive weed information sheet, click below to download.
