Alert for turnip yellows virus in canola and brassica

Seasonal conditions have been favourable for aphids in early 2026, with high rainfall and the green bridge driving the population.

SARDI visited a site of forage brassica in the southeast of South Australia which had high populations of aphids in early April.

The brassica showed the typical purpling leaves of turnip yellows virus (TuYV) in the emerging crop.

Testing of the crop found an extremely high proportion of TuYV taken in a transect of the paddock, with infection nearing 100%.

The aphid population has decreased with the cooler weather, however highly infected fields and surrounding weeds could act as disease reservoirs for early TuYV infection of canola. GRDC has produced a new fact sheet that can help with this – see Manage turnip yellows virus in canola.

Please email Dr Nicole Thompson if you are seeing signs of TuYV in emerging canola, or any other virus-like symptoms in your crops.

SARDI is part of the GRDC national investment 'Effective virus management in grain crops' (DAW2305-003RTX).