The Agricultural and Horticultural Development Board (AHDB) is confirming that its new Barley Yellow Dwarf Virus (BYDV) online tool will be launched at the beginning of September.

It replaces the existing model, which is driven by a T-Sum calculation.

Significantly, the new model draws information from a disparate range of data sources, including the Rothamsted Insect Survey.

Other variables to be factored-in include the growing impact of BYDV tolerant winter barley varieties, sowing dates, and projected grain prices at harvest.

According to AHDB, genetic analysis of the different aphids that act as a vector for BYDV will continue apace with real time data from this work.

New model

AHDB staff stress that the new model will not deliver recommendations in terms of when best to spray newly planted cereal crops with an insecticide.

Rather, it will provide growers with an assessment of the variables impacting on the spread of BYDV at a particular time.

The new model has been developed on the back of a four-year research and development programme carried out by agricultural consultancy Agricultural Development and Advisory Service (ADAS). The work was specifically commissioned by AHDB.

There is a strong expectation that the updated BYDV model can deliver better crop outcome scenarios with a reduced reliance on the use of insecticides to control infection levels within cereal crops.  

Post-launch, the new model can be accessed free-of-change by arable farmers throughout the UK.

AHDB is currently seeking the views of growers regarding tweaks that can be made to the new tool prior to launch.

BYDV

Recent years have seen BYDV constituting a very significant yield threat when it comes to the growing of both winter and spring cereal crops.

The disease is spread by an aphid vector throughout the main planting seasons.

AHDB is confirming that yield losses of up to 80% can be effected by BYDV.

In an Irish context, the average yield loss projected is in the region of 1.5t/ac.

However, it is now accepted that extremely complicated processes are at play when it comes to the spread of BYDV, all of which associated with the relationship that develops between aphids, the virus they carry and the host cereal plant.

And each link in the chain has a number of factors that can work through to the final impact – if any - that BYDV can manifest within a crop.

For example, there are different forms of the BYDV virus, with differing capabilities of interfering with crop growth patterns.

In addition, the timing of the initial infection and the stage of plant growth can have a key impact on subsequent crop performance.