BYDV Assist

Following the loss of neonicotinoid seed treatments in cereals, autumn crops will be at higher risk of Barley yellow dwarf virus (BYDV) infection from aphids. An integrated pest management approach should be taken to reduce the risk, as well as regularly scouting fields for aphid presence which indicates risk of primary infection. Use the BYDV Assist tool to optimise spray timing to target the second generation of aphids, based on a model using the T-sum 170 day degrees (DD) threshold.

Primary infection occurs when winged aphids land on single plants and transfer virus, secondary spread is when the population of wingless aphids build up sufficiently to initiate aphid spread from the original infection point causing larger area of infection. Controlling larger areas of infection from secondary or even tertiary spread (occurs when the second generation spreads further to cause full field infection) will be key this autumn at reducing the impact of BYDV in cereal crops.

BYDV Assist is a scouting app designed to aid in decision making, in-field observations are still required.

BYDV Assist - how it works

1. Add your field by pressing the + icon in the bottom right corner.

2. Input your location, BYDV Assist uses a 4 km accurate weather model.

3. Select your drilling and emergence date, this is when the 170 Day Degrees (DD) is calculated from.

4. If a foliar insecticide treatment has been applied input the date treated. This will reset the calculation to 0DD for 1 week.

5. A notification is given at 145DD to allow a couple of days to inspect the field and another when the 170DD threshold is reached.

6. If aphids are present when the 170DD is imminent or occurring an application spray is recommended.

7. The included spray application guide can be used to plan optimum application timings, once treatment is warranted.