38th Meeting of the Working Party on Plant Protection Products

Lisbon, 2008-05-20/21


The 38th Meeting of the Working Party on Plant Protection Products took place in Lisbon on 2008-05-20/21, at the kind invitation of the Portuguese NPPO. 23 participants from 16 EPPO member countries and ECPA attended the Working Party. 


This EPPO Working Party directs and supervises the technical work of many EPPO Panels concerned with the registration of plant protection products. The report of the meeting prepared for the EPPO Council and Executive Committee presents in greater detail the discussions, decisions and recommendations which were made by the Working Party; some of major points are summarized here.



EPPO Standards for approval

The Working Party on Plant Protection Products continues to approve a steady flow of new or revised EPPO Standards in series PP1 Efficacy Evaluation of Plant Protection Products. A set of 18 standards in this series are to be submitted to the Executive Committee and Council of EPPO in September 2008 for definitive approval and publication:

Ten specific standards on efficacy evaluation have been revised:

  • Leptinotarsa decemlineata (revision PP 1/12)
  • Phytophthora infestans on potato (revision PP 1/2)
  • Weeds in Allium crops (revision PP 1/75)
  • Weeds in flower bulbs (revision PP 1/88)
  • Weeds in leafy vegetables (revision PP 1/89)
  • Weeds in orchards (revision PP 1/90)
  • Weed control between crops (revision PP 1/98)
  • Weeds in root vegetables (revision PP 1/99)
  • Weeds in Ribes and Rubus (revision PP 1/119)
  • Regulation of growth in stone fruits by pre-harvest in field foliar applications (revision PP 1/208)


Eight new standards have been developed:

  • Mating disruption pheromones
  • Aphid vectors of non-persistent viruses on flower bulbs and flower tuber crops
  • Aphid vectors of non-persistent viruses on seed potatoes
  • Thrips tabaci in Allium crops
  • Alternaria solani & Alternaria alternata on potato and the outdoor production of tomato
  • Disinfection in plant production
  • Take-all (Gaeummannomyces graminis)
  • Regulation of growth in stone fruits by pre-harvest in field foliar applications


The first extrapolation tables to accompany EPPO Standard 1/257 Efficacy and crop safety extrapolations for minor uses have been finalized, as well as guidance documents to accompany those tables (guidance on the format and content of a table for extrapolation, and a list of crop groups). They are divided in tables for effectiveness and tables for crop safety. Crops concerned are vegetable Brassicas, and pome and stone fruit


Programme of activity

The Working Party realized that the whole programme of activity centres around the creation and revision of general and specific standards on efficacy evaluation. It was clear that these standards are very much in demand and their maintenance and further development is a key activity of the Organization. A large number of new specific standards was proposed. 

The Panels on Efficacy Evaluation will carry on developing tables with specific extrapolations, based on crop/pest groupings and according to the format developed by the Panel on General Standards.


Concerning resistance, an online questionnaire is available with the aim to build up a database of resistance expertise available in EPPO countries to improve information exchange within the region. The next workshop dealing with resistance management will be on carrot fly. 

Discussion subjects

The following important topics were discussed by the Working Party: the concept of “comparative assessment” which is being introduced in the revision of the EU Directive 91/414, loss of product diversity (as result of the EC review programme) that particularly affects minor crops and uses and may increase resistance management problems (see the conclusion of the workshop EPPO Workshop on sustainable pest control and fewer active substances. The Working Party explored the possibilities for developing further some of these topics. It is planned that a workshop will be organized to discuss the concept and consequences of comparative assessment.