Agriculture and Horticulture Development Board

BYDV Management

Barley yellow dwarf virus (BYDV) management tool for cereals

Aphids can transmit barley/cereal yellow dwarf viruses (BYDV). Initially, aphids colonise relatively few crop plants. However, the second-generation tends to move away from the plant originally colonised. Controlling this generation is a key part of a BYDV management strategy.

The second generation is likely to be present when the accumulated daily air temperatures, above a baseline temperature of 3ºC, reaches T-Sum 170.

T-Sum calculations should start either:

On the day of crop emergence
Following a pyrethroid application (account for product persistence, see label)

Enter the T-Sum start date in the box then select an area – a weather station or stations (by selecting a ‘Region’). The chart then displays the T-Sum results (blue line).

Crops are at an unacceptable risk when the line reaches 170. At this stage, check crops and consider treatment.