Case study: Ian Leulf – control of rye grass and black oats in a retained stubble system.
Property size: 3500 ha at Weethalle, NSW.
Enterprises: Dryland wheat, barley, sheep.
Soil and pH: red sandy clay loam soils with a pH of 4.5.
Overview:
The Leulf’s generally follow a three year cropping program involving wheat, barley then fallow. After trialling numerous pulses and break crops, including brown manuring Ian felt it was a safer option in their environment to simply maintain a fallow as a break.
Although black oats is more of an issue for the Leulf’s than rye grass, they have encountered resistance problems in populations of ryegrass in their stubble retained farming system.
Rye grass and black oats control:
A few years ago the Leulf’s encountered a failure with Hoegrass on a ryegrass population. They switched from Group A herbicides and starting using strategic cultivation (with wheat) to include the use of pre-emergents Avadex and Treflan. This has allowed them to quickly get back on top of the issue.
They have also started growing Clearfield barley (a herbicide tolerant variety used in combination with the broad spectrum Intervix® herbicide) which has given them another weapon against grasses and effectively allowed them to grow barley with confidence.
Another method to assist control the Leulf’s have been experimenting with for the past couple of years is diverting chaff into the tramlines at harvest, depending on the stubble load and if they can achieve this without slowing the header too much.
Windrow burning is another tool Ian is looking at into the future if rye grass becomes an issue but is not confident it will have much effect on black oats.
When there is a black oats issue in a given paddock Ian makes it a priority to harvest those paddocks as early as possible to reduce seed drop as much as possible.
Grazing plays no part in Ian’s control of black oats and rye grass.
Key issues for control of rye grass and black oats:
- Don’t hesitate to test for resistance if poor control from spraying is observed.
- Use cultivation if necessary with tyned implements for use of pre-emergent chemicals, exposing buried seed and manual control.
- Don’t rely on one chemical group.