What's Happening?
Syngenta has released its blight management recommendations for the 2026 season, emphasizing the importance of robust fungicide programs due to the emergence of more aggressive blight strains and the risk of resistance development. The advice comes after
the confirmation of the first case of EU_43 blight in the UK, found in Suffolk. Syngenta Technical Manager, Andy Cunningham, highlighted that the current blight population in England is dominated by the EU_36 strain, which is aggressive but currently has no resistance issues in the UK. However, some strains of EU_43, including a sample found in the UK, have shown some resistance to CAA and OSBPI fungicides. The EU_43 strain caused significant problems in Denmark and the Netherlands in 2021 and 2022 due to limited fungicide options and reliance on repeated CAA treatments. When growers in Denmark changed practices to alternating fungicide modes of action and mixing strategies in 2023, the EU_43 population declined rapidly. Conversely, in Holland, where single-active blocking protocols continued, EU_43 remained dominant. The evolution of EU_43 into EU_46, which has been identified in the UK, poses a greater threat of resistance to the OXTP active.
Why It's Important?
The evolving landscape of blight strains and increasing fungicide resistance pose significant challenges for agricultural productivity and food security. The spread of resistant strains like EU_43 and EU_46 could lead to substantial crop losses if not effectively managed, impacting farmers' livelihoods and potentially increasing food prices for consumers. The experience in Denmark and the Netherlands demonstrates that effective management strategies, such as alternating and mixing fungicide modes of action, are crucial to controlling resistant strains. Failure to adopt such practices, as seen in Holland, can lead to the continued dominance of problematic strains and further evolution of resistance. This situation underscores the need for continuous research and development in agricultural science to provide growers with effective tools and strategies to combat these threats. The economic implications for the agricultural sector, particularly for potato growers, are substantial, as ineffective blight control can lead to reduced yields and quality, affecting market supply and profitability.
What's Next?
Syngenta advises growers to implement a strategy of mixing and alternating blight fungicides in a robust season-long program. Key recommendations include always applying Revus in mixture with a fungicide with a different mode of action, applying Revus or other CAA fungicides in strict alternation, and preferably using them as preventative treatments. Growers should use up to six applications of mandipropamid or other CAA fungicides, making up no more than 50% of the total sprays. Good mix protectant partners for Revus include fluazinam, propamocarb, amisulbrom, and cyazofamid. The company also emphasizes the importance of proper application techniques, such as using angled nozzles and drift retardants, to maximize leaf targeting and enhance performance. Continued monitoring of blight strains and their resistance profiles will be essential to adapt management strategies as new threats emerge. Research into new phosphonate products is also underway, which may offer additional partner solutions to mitigate resistance and provide alternatives in the event of mancozeb loss.
Beyond the Headlines
The ongoing battle against crop diseases like blight highlights broader issues in agricultural sustainability and the arms race between pathogens and human intervention. The rapid evolution of blight strains and their resistance to existing fungicides underscore the need for integrated pest management approaches that go beyond chemical controls. This includes exploring genetic resistance in crops through breeding programs, adopting precision agriculture techniques to optimize fungicide application, and fostering greater collaboration between researchers, industry, and farmers. The development of resistance also raises questions about the long-term efficacy and environmental impact of current fungicide use. There is a growing imperative to develop more sustainable and environmentally friendly solutions to crop protection, reducing reliance on chemical inputs while ensuring food security. This situation also points to the global interconnectedness of agricultural challenges, as blight strains can spread across borders, necessitating international cooperation in research and disease management strategies.
