Miranda Bracy is well into her TMAF-supported PhD. She aims to help find control measures for Barley yellow dwarf virus (BYDV), one of the most damaging threats to UK cereals with potential losses up to 84% in wheat if early infections take hold.
Farmers need new, sustainable tools to protect crops while reducing reliance on insecticides. My PhD project, based at Harper Adams University and supported by The Morley Agricultural Foundation and BBSRC CTP-SAI, is part of this effort.
The BYDV virus spreads through aphids, mainly bird cherry-oat aphid and grain aphid, whose management has become more difficult following the loss of neonicotinoid seed treatments and rising pyrethroid resistance.
By combining laboratory experiments and fieldwork at Morley in collaboration with the AHDB Strategic Cereal Farm East, I’m investigating potential strategies to prevent infection, improve forecasting and increase disease management alternatives. Since October 2025 I have been visiting the farm at Morley monthly to monitor aphid populations, as part of the AHDB Strategic Farms East project on BYDV monitoring and modeling.
Can biostimulants help the battle against BYDV?
One area of interest is whether biostimulants like silicon can make crops less attractive to migrating aphids or limit their ability to reproduce and spread throughout a field. Although silicon has shown mixed results – with some studies reporting reduced aphid populations and others finding little effect – I think it could be a promising option as part of a wider IPM toolkit. Understanding when and how these treatments work will help growers make more informed decisions.
How to make the right decisions on insecticide use?
My research will also assess the biological underpinnings behind decision support tools like the ADAS T-Sum model to assess their ability to reliably guide spray decisions for growers across the UK. This work will follow AHDB project report 646, which showed that DSS tools can reduce unnecessary insecticide applications while maintaining or improving BYDV control. Paired with better aphid monitoring systems, these tools have real potential to help growers strategically target and time insecticide applications.
Do beneficial insects help control BYDV?
I also plan to investigate the role of natural enemies. Hover-flies, ladybirds, carabid beetles, and parasitoid wasps can significantly suppress aphid populations in spring cereal crops through predation and parasitism. However, little is known about their ability to mitigate or suppress BYDV spread in winter crops. Additionally, I aim to incorporate varietal resistance and crop genetic diversity throughout my experiments by utilising widely grown, high-yielding cultivars as well as those marketed with BYDV resistance traits.
Read more about my research work in the article Preventing, predicting and protecting crops from vectors of barley yellow dwarf virus (BYDV).
