Climatic variability and resistance pressure are contributing to evolving downy mildew dynamics in grapevine, potato and tomato across southern Europe. Ascenza and Selectis report that new crop protection solutions are under development and are expected to be launched shortly.
Shifting epidemiology under climate pressure
Downy mildew pathogens — notably Plasmopara viticola and Phytophthora infestans — have long been part of the agronomic landscape. However, their behaviour has shifted markedly in recent seasons.
"What once showed relatively stable patterns with predictable infection cycles and well-defined application windows has now become a scenario marked by climatic variability and increasingly erratic infection events," technical teams from Ascenza and Selectis observe.
Weather variability is now a dominant factor. Sudden alternations between heavy rainfall and high temperatures are generating unexpected infection windows and increasing the number of disease cycles. "Heavy rainfall one day, sudden heat the next, generating unexpected infection periods," the teams note, adding that in some seasons "downy mildew just doesn't let up."
From forecasting to real-time agronomy
Traditional strategies based on seasonal forecasting are proving insufficient. The current scenario requires continuous monitoring, rapid response, and tools capable of performing under variable conditions.
"Today, the fight against downy mildew no longer depends solely on good practices but on reliability, especially when the weather is highly unstable."
Regulatory pressure and resistance risk
At the same time, regulatory constraints are reducing the number of available active substances across Europe. This increases dependence on fewer modes of action and heightens resistance risks.
"When agriculture is forced to work with fewer tools, every technical decision must be more carefully considered." They stress the need for solutions that combine or alternate modes of action while delivering preventive, curative and anti-sporulating performance.
Protecting yield, not just leaves
The technical focus is shifting from foliar protection to safeguarding yield and crop value.
"Controlling the disease 'on the leaf' is not enough. We need to preserve the fruit, and this is where protection must be truly solid."
This means ensuring efficacy even under rain, delayed applications, or when early infections are already present; conditions that are increasingly common in unstable climates.
Quality requirements across the value chain
Beyond agronomic performance, crop protection strategies must support quality requirements from field to processing.
"The end consumer may never see a downy mildew lesion, but demands consistency in flavour, aroma, texture, and quality." This reinforces the importance of solutions compatible with processing standards, without negative effects on sensory characteristics or the plant and soil microbiome.
Demand for predictable performance
With multiple uncertainties to manage, growers and technicians are prioritising predictability. Key technical requirements include dual systemic and penetrating action, high rainfastness, preventive and anti-sporulating capacity, and compatibility with integrated crop protection programmes.
"Agriculture has always been demanding. Now it is demanding, urgent, and unpredictable all at once," they state.
New solutions approaching launch
In response, Ascenza and Selectis are advancing new anti–downy mildew solutions, with demonstration field trials already underway. These developments are designed to address climatic unpredictability, resistance pressure, and the need for consistent performance.
"The technical work underway seeks to anticipate growers' needs and ensure that the sector has tools aligned with the best international practices in integrated crop protection."
For more information:
Ascenza
ascenza.com
