In 2014, canola crops across SA, western Victoria and some parts of NSW were severely affected by beet western yellows virus (BWYV) (synonym; turnip yellows virus). Significant rainfall over much of the southern cropping zone in January 2015 has initiated a green bridge, which has the potential to host large populations of aphids as well as viruses between growing seasons. This has increased the risk of inducing BWYV outbreaks this year.
Early management decisions are key to reducing aphid and virus risk in 2015.
The GRDC has released a Tips and Tactics for Reducing Aphid and Virus Risk in 2015
The key points are:
- Destroy the green bridge over summer and autumn prior to sowing.
- Do not sow canola into desiccating weeds/canola volunteers; otherwise, aphids will move directly from the weeds to the emerging seedlings.
- Monitor green peach aphid (GPA) populations on weeds, volunteers and seedling canola crops.
- Use seed treated with a neonicotinoid insecticide and ensure proper application and coverage of seed dressing for efficacy against GPA.
- Ensure correct identification of GPA before applying insecticides to protect seedling canola.