Problem
Production of potatoes is of prime agricultural importance in the Netherlands. Late blight, caused by the oomycete Phytophthora infestans is the most important threat to this crop. Control of the disease is only possible by abundant use of fungicides, which use amounts to more than 50% of all fungicides used in The Netherlands. For more than a century the Phytophthora population was rather uniform and control was possible by integrated crop protection in combination with more or less resistant potato cultivars. However, due to the importation of infected potato material, the Phytophthora population has changed during the last 20 years, becoming more aggressive, producing persistent oospores, and showing more genetic variability thus, enabling adaptation to the present resistant cultivars. The increased aggressiveness, the decrease of resistance and, consequently, the large input of fungicides form a threat to sustainable potato culture in The Netherlands. This threat has led to the Netherlands Initiative on Late Blight (NILB), 2003–2012.
Aim
Reduction of the use of fungicides to control P. infestans in potato by 75% in 2012:
- Integrate all present and new research in the Netherlands and to focus all projects on this 2012 aim.
- Hand over the steering of all research to a board of representatives from the potato sector to ensure commitment to and application of the results of all short term and long term research.
- Combine research (Wageningen UR), policy (Ministry of Agriculture) and potato sector in NILB to ensure that each party takes its responsibility for reaching the 2012 aim.
Integrated Research
All research is brought together in six themes that form a tightly integrated program.
Fig. 1. The results from five themes of short- and long-term research are integrated in the Phytophthora toolbox (theme 6) and translated to be applicable by the potato sector.
Theme 1: Phytophthora Toolbox
Coordinator: dr. Huub Schepers
Within the Toolbox results from the other five themes will be translated into practical solutions resulting in an integrated control strategy for P. infestans with a minimal input of fungicides.
Theme 2: Population Biology
Coordinator: dr. Wilbert Flier
This theme is aimed at generating knowledge on functional variation in P. infestans that can be used to improve late blight management strategies and risk assessments.
Theme 3: Epidemiology
Coordinator: dr. Geert Kessel
This theme aims to contribute to improved, reliable, year round control strategies through additional (quantitative) insight in the potato late blight disease cycle and epidemic build up.
Theme 4: New sources for resistance
Coordinator: dr. Ronald Hutten
In this theme an elaborate and systematic search for new genes is performed in some hundred wild species, related to potato. Whenever new major resistance genes are found, they will be characterized for variation in function and combined by breeding.
Theme 5: Genomics potato-Phytophthora interaction
Coordinator: dr. Edwin van der Vossen
The aim of this theme is to study the identification of specific genes of potato and Phytophthora, which in the initial stages of an infection determine the outcome of the interaction. Furthermore, the generation and analysis of defense-related mutants, and the identification and characterization of genes involved in non-host resistance to P. infestans in Arabidopsis are studied to unravel the role of key regulators of defense in late blight resistance.
Theme 6: Genomics Phytophthora infestans
Coordinator: dr. Francine Govers
In this theme current genomic and EST sequence data of P. infestans will be screened as efficiently as possible to identify candidate genes that possibly encode for pathogenicity and (a)virulence factors and to identify variable regions in the genome that can be used for the efficient development of molecular markers.
Organisation of NILB
Fig. 2. Organisation-scheme of NILB. The Steering Committee is steering Wageningen UR research as well as communication and implementation of the results
Central is the Steering Committee with representatives from the stakeholders. Although the Dutch Ministry of Agriculture is financing the major part of the research at Wageningen UR, their role in the Steering Committee is modest. The potato sector (breeders, growers and trade) has the most prominent role in the Steering Committee, as this sector is able to keep research on the applied track and to communicate and implement the results into practice. As shown in Fig. 2 “steering” occurs in two annual loops: one is steering the Wageningen UR research to fill the Phytophthora ‘Toolbox’, another is implementing the toolbox in practice. The implementation is monitored in different farming systems with respect to environmental effects, and problems will be reported to Wageningen UR for feed-back. Whenever a tool is found to be useful and robust, the Steering Committee can make the application of it mandatory for all farmers.