Barley Yellow Dwarf Virus Threatens Cereal Yields: New Tools and Tolerant Varieties Offer Hope
Recent years have seen Barley Yellow Dwarf Virus (BYDV) pose a significant threat to winter and spring cereal crops, impacting yields across the UK and Ireland. Spread by aphids, the virus can reduce yields by up to 1.5 tonnes per acre1. Yet, advancements in plant breeding and a better understanding of aphid behavior are providing arable farmers with more effective control measures.
The Challenge of BYDV
The impact of BYDV was a key discussion point at a recent spring crop walk hosted by the College of Agriculture, Food and Rural Enterprise (CAFRE) on the South Down farm of Shaw Hanna12. Teagasc tillage specialist, Shay Phelan, highlighted that while inputs aim for yields around 4 tonnes per acre, these are often not realized due to BYDV infestations12. The virus’s spread is intricately linked to aphid populations and environmental factors.
Developing BYDV Tolerance and Resistance
The development of spring and winter cereal varieties with genuine resistance to BYDV is considered the optimal control solution. Independent research conducted by Teagasc scientists has confirmed that claims of BYDV tolerance by plant breeding companies are valid1. Several winter barley varieties now demonstrate a degree of tolerance to the disease.
Practical Management Strategies
Effective BYDV management involves a multifaceted approach:
- Sowing Date: March-sown spring barley generally doesn’t require insecticide treatment, while April-sown crops typically do1. Later sowing dates for autumn crops can also reduce aphid exposure.
- Monitoring: Regularly inspect fields for aphids, particularly in sheltered areas near headlands, before planting1.
- Insecticide Application: A single application of aphicide at growth stage 14 is generally most effective1.
- Field History: Identify fields with a history of BYDV to prioritize monitoring and preventative measures.
New Tools for BYDV Management
The Agricultural and Horticultural Development Board (AHDB) is launching a new BYDV management tool for the 2026 autumn planting season. This web-based facility aims to address the limitations of previous tools, which were developed after the withdrawal of neonicotinoid seed treatments in 20181. The updated model considers factors such as aphid species (bird cherry-oat aphid being the most significant vector), temperature, rainfall, crop type, sowing date, and predicted yield1. It provides recommendations on optimal spray timings and cost-benefit analyses.
Aphid Monitoring Networks
Teagasc operates an aphid monitoring network with three suction towers located in Carlow, Cork, and Dublin1. These towers monitor aphid migrations, with data indicating that flights typically commence around mid-March and continue through November, influenced by temperatures between 11°C and 15°C.
Looking Ahead
While significant progress has been made in understanding and managing BYDV, ongoing research is crucial for developing truly resistant cereal varieties and refining management strategies. The combination of tolerant varieties, informed decision-making tools, and proactive monitoring will be key to minimizing the impact of this persistent threat to cereal production.