Crop protection company Syngenta have launched a new smartphone app to help optimise insecticide spray timings.

Since the loss of neonicotinoid seed treatments in cereals, autumn drilled crops are at higher risk of Barley yellow dwarf virus (BYDV) infection from aphids.

This is particularly the case for early-sown winter barley crops. Primary infection occurs when winged aphids land on single plants and transfer viruses. Secondary spread is when the population of wingless aphids build up sufficiently to initiate aphid spread from the original infection point, causing a larger area of infection.

The app, which is available to Irish growers, forecasts and indicates the optimal spray timing for the control of secondary generation of aphids, based on the accumulation of 170 day degrees from crop emergence.

Controlling larger areas of infection from secondary or even tertiary spread (which occurs when the second generation spreads further to cause full field infection) will be vital to reducing the impact of BYDV in cereal crops this autumn.

Watch a tutorial on the app below:

BYDV Assist - how it works

1. After downloading the app on your Apple or Android app device, add your field by pressing the + icon in the bottom right corner.

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

3. Select your drilling and emergence date - this is where 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 one 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.