The Dutch Taskforce Phytophthora: A Coordinated Response to Late Blight

By Geert Pinxterhuis and Geert Kessel, Wageningen University and Research

After the severe late blight outbreaks of 2023, the Dutch potato sector faced a stark reality: potato cultivation had become significantly more expensive, risk-prone, and uncertain. The extreme infection pressure—driven by increasingly erratic weather patterns and the rapid evolution of Phytophthora infestans—threatens the future viability of potato farming in Northwest Europe.

The 2023 crisis exposed a troubling trend: both the effectiveness of plant protection products (due to rapidly developing resistance) and the durability of host plant resistance (due to rising levels of virulence) were eroding fast. In response, stakeholders from across the potato value chain—breeders, growers, advisors, processors, and producers of plant protection products—formed the Dutch Taskforce Phytophthora. This united initiative seeks to restore control over late blight through a strategic, integrated, and science-based approach.

Strategic Goals of the Taskforce

The primary objective is to re-establish sustainable control over Phytophthora infestans through:

• Accelerated adoption of integrated crop management (ICM) practices in potato cultivation.

• Promotion of responsible and effective use of plant protection products (PPPs) to optimize efficacy and minimize resistance development.

• Minimization of PPP emissions to safeguard the longevity of the available product portfolio.

• Preservation of late blight resistance (R) genes, which are critical for building durable, long-term disease control strategies.

A Unified Communication Strategy

Through intensive stakeholder dialogue, the Taskforce developed a shared message and collective commitment. Scientists, advisors, producers and distributors of PPP’s now work in sync to deliver consistent guidance across multiple communication channels, targeting the ~9,550 Dutch potato growers.

Core Focus Areas:

• Sustainable ICM-based cultivation and disease management

• Strict hygiene practices in line with Dutch late blight regulations (e.g., on dumps, volunteers, and infection control)

• Cultivar selection: Accelerating the adoption of potato varieties with enhanced late blight resistance

• Active protection of resistant cultivars to delay pathogen adaptation and safeguard genetic resistance

• Optimized spray strategies: Combine and alternate actives (FRAC MoA groups); use decision support tools for precise timing

• Allotment grower awareness: Educating hobby growers on their role and responsibilities in disease management

Communication Tools and Resources

To support growers, agronomists, and advisors in implementing the new strategy, the Taskforce has published tailored materials in both print and digital formats via www.bo-akkerbouw.nl/pi:

• A strategy flyer outlining the integrated control approach and its practical components

• A resistance table categorizing cultivars with enhanced late blight resistance based on their genetic background

• A spray strategy matrix grouping all approved PPPs in the Netherlands by active ingredient and Mode of Action (FRAC group), enabling growers to evaluate and optimize their application programs

• The PhytoAlert app, which allows farmers and advisors to report local late blight outbreaks by postal code, offering real-time regional disease pressure updates for better-informed decisions

Initiative by BO Akkerbouw

The Dutch Taskforce Phytophthora was established under the guidance of the Plant Health Action Plan steering committee, an initiative of BO Akkerbouw, the Dutch arable farming organization. For more details and resources (in Dutch), visit www.bo-akkerbouw.nl/pi.