How to survey plants?

“Plants can get sick, too!” was one of slogans developed in creative EPPO environment. Now plants are in active growth all over the globe and the key question of this article is, how a newcommer among viruses, bacteria, fungi or another fatal pathogen of plants could be found at its early epidemiologic stage, when an eradication of disease is still possible?

When I started working with Slovenian National Plant Protection Organisation as head of plant health department 20 years ago, I first put into annual plan a translation of international FAO Glossary of phytosanitary terms (FAO Plant Protection Bulletin 38(1)). A terminology working group composed of chief officials, experts of plant protection and proffesors of phytomedicine in agronomy and forestry started to discuss proper terms and definitions in national language. For many of them this was a start of informal learning of international dimension in the field. Glossary was immediately used in practice, as in 1999 we started to plan annually a set of offical monitorings for quarantine pests, financed from national budget and implemented through the official service. We had numerous discussions whether plant health checks should be done by phytosanitary inspectors or by authorised plant protection experts from institutes. Phytosanitary inspectors had appropriate authorisations, but they were busy with import controls on the borders and they lacked knowledge of field surveys, biology of pests, symptoms and signs of infestation.

Based on discussions about phytosanitary terms like: pest, testing, visual inspection, quarantine area, buffer zone, pest-free area, phytosanitary action, surveillance, etc. also national legislation was developed in 2001 (Law on plant health protection). Among terms we were not able to find proper translation for survey (fr. prospection), which should be done systematicaly and science-based. Still today I notice that in many Slavic languages it is translated as ‘”anketa”, which means systematic research of public opinion by questionaire. My proposal to use a bit obsolete word “prospekcija”, which is used in geodesy, was not accepted, so we used “sistematična raziskava” for survey and “posebni nadzor” for specific surveys in legislation. However, understaning of the term by hierarchy permitted us to involve scientific staff part-time into official procedures and surveillance.

We decied to upgrade authorisations of experts from institutes to “official surveyors” (svn: uradni pregledniki), gave them official badges and official phytosanitary ID cards and thought them basic official procedures, including how to record field surveys for the official use in case of positive finding of quarantine pests. Since then, surveys are succesfully implemented and have grown from initial 10 programs on quaratnine pests in 2000 to 35 in 2012, and are doubled to 70 programs today.

Authorised surveyors covered inland territory, where host plans were grown, inspectors complemented the data about import and internal market controls. Several models of information systems, including weather conditions, prognostic models and geographical analysis with mapping of infested or pest-free areas were developed and results presented to the public on websites. Since 2013, phytosanitary inspectors have not been actively involved into survey programs, but by following a parallel official control program they act in every case, when a quarantine pest is found and phytosanitary measures needed.

What is the most important, we have managed to adjust the EU legislation completely to the IPPC convention and global ISPM standards. Since 2014, a methodology of surveys in the European union has been more harmonised, mainly due to cofinancing of the Member States’ survey programs by the EU. Minimum requirements for national survey programs are respected (Regulation (EU) No. 652/2014) that each survey card or survey protocol contains:

  • description of the pests included in the programme;
  • a description and demarcation of the geographical and administrative areas in which the programme is to be applied and a description of the status of those areas as regards the presence of the pests concerned;
  • the duration of the program indicated (has to be several years);
  • the number of visual examinations, samples and tests scheduled for the pests and plants,
  • plants, products and other objects concerned cleraly defined;
  • the estimated budget assessed;
  • the targets to be attained by the completion date of the program and the anticipated benefits thereof; and
  • appropriate indicators to measure the achievement of the targets of the programme.

The main indiciators used are number of visual checks and number of samples taken for specific objective of survey, which can be:

  • Detection – Surveys for pests that are not known to be present in a specific area with the aim of early detection of new incursions; results serve as an evidence of pest free area (ISPM 5: Survey conducted in an area to determine if pests are present).
  • Demarcation – Surveys to delimit infested from pest free areas and establishing buffer zones, surrounding or adjacent to an area officially delimited for phytosanitary purposes in order to minimize the probability of spread of the target pest into or out of the delimited area, and subject to phytosanitary or other control measures, if appropriate (ISPM 5: Delimiting survey is conducted to establish the boundaries of an area considered to be infested by or free from a pest).
  • Monitoring – Surveys focused on pests that are known to be present in an area/region (ISPM 5: An ongoing survey to verify the characteristics of a pest population).

By my experience, the risk based surveys have higher effectiveness comparing to random sampling for new and emerging pests, which have not yet been established in the area. So, it is of utmost importance to have in the team the experts in pest biology, pathways of introduction and early detection, who design the survey for certain new pest. Luckely, in 2020 the plant health community in Europe has got support from EFSA’s Plant Health Panel (European Food Safety Authority), which prepared some survey cards in support to survey planning. The scheme below is adjusted from EFSA’s understanding of ISPM 6 and ISPM 31 on selection of inspection unit for sampling.

Together with ISPMs and EPPO diagnostic and inspection protocols the reliable sources of information have been available to plan annual surveys for quarantine pests. Survey in this case means systematic applied research or examination implemented by the NPPO as an official procedure conducted over a defined period of time to determine the characteristics of a pest population or to determine which species are present in an area (ISPM 5).

Results of general surveillance and specific surveys are considered reliable and well-structured information on the presence, absence or distribution of plant pests in the country, and information about host plants or commodities as pathways of their introduction and spread. Structured surveillance protocols describe the methodology of surveillance, whether general or specific. (ISPM 6)

Selecting epidemiological and inspections units for field survey on quarantine pests for target host population (adjusted by V. Knapic from EFSA methodology in survey cards).

As terminology is the most important standard in every scientific field, let me mention how it started in phytosanitary. FAO Glossary has been developing since 1986, when North American (NAPPO, led by Hopper) and European plant protection organizations (EPPO, led by Smith) recommended creation of a “Core vocabulary of phytosanitary terms“. The father of this idea was Dr Ian Michael Smith, the director of EPPO, who succesfully led not only development of terminology in the European region, but also in the global phytosanitary society under the umbrella of International Plant Protection Convention, where the Glossary panel has been working since then (he chaired it until November 2014). Many international experts worked in global glossary panel, who cared for concise use of terms. Among native English speakers John Hedley from NZ should be also mentioned. Ian Smith set up the EPPO’s most important fields of work, like coding and systematic work for regional standards and EPPO Global database, risk assessment including alien invasive plants, and all other scientific support needed for official services in member countries. He successfully cooperated with the first plant health officer of the European Commission Marc Vereecke, who was developing the EU phytosanitary directive 77/93/EEC, nowadays known as directive 2000/29/EC (but also replaced by Regulation (EU) 2016/2031 on 14 December 2019).

Their cooperation led to formation of core groups of international experts, who worked in EPPO Panel on global affairs and working party on phytosanitary regulation, in Commision standing commettee and in EU Council working group on IPPC affairs. Working two decades in these core groups at EU and global level of Comission on Phytosanitary Measures, I have wittnessed accesion of the EU to the IPPC in 2005 and increasing use of IPPC convention and its ISPM standards in EU legislation. Just before Marc Vereecke retired in 2008, he gave me a legal text on the EU accession (on three different papers, printed by typewriter and copied many times in his archive to become hardly legible), to be able to draft rules of procedures for the EU at preparing common positions for the global CPM sessions. During Presidency of Slovenia to the EU in 2008, these rules of procedure were adopted, and serve also today its purpose of agreeing on competences between Member States and the European Commission, who speaks on certain CPM agenda point when adopting international standards for phytosanitary measures (ISPMs).

But “survey” still remains an issue for translation into many languages…

Published by Lasta

Plant pathology is my profession, plant protection is my job, genealogy is my passion...

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