Commodity risk assessment of Betula pendula and Betula pubescens plants from the UK

Abstract

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as ‘High risk plants, plant products and other objects’. This Scientific Opinion covers plant health risks posed by plants of Betula pendula and B. pubescens imported from the United Kingdom (UK) taking into account the available scientific information, including the technical information provided by the UK. The commodities were grouped in the risk assessment as (a) bundles of 10–20 graftwood/budwood (up to 1-year-old), (b) bare root plants which include bundles of 25 or 50 seedlings or transplants (1–2 years-old), bundles of 5, 10 or 15 whips (1–2 years-old) and single bare root plants (1–7 years-old), (c) plants in pots which include bundles of 5 and 10 cell-grown plants (1–2 years-old) and rooted plants in pots (1–7 years-old), and (d) large specimen trees up to 15-years-old. All pests associated with the commodities were evaluated against specific criteria for their relevance for this opinion. Two EU quarantine pests i.e. Meloidogyne fallax and Phytophthora ramorum (non-EU isolates) and two protected zone quarantine pests i.e. Entoleuca mammata and Thaumetopoea processionea fulfilled all relevant criteria and were selected for further evaluation. For the selected pests, the risk mitigation measures described in the technical dossier from the UK were evaluated considering the possible limiting factors. For these pests an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. In the assessment of risk, the age of the plants was considered, as larger trees are more likely to be infested mainly due to longer time grown in the field. In addition, larger canopies and root systems are more difficult to inspect, thereby making the detection of pests more challenging on large trees. The likelihood of pest freedom varies among the pests evaluated, with M. fallax being the pest most frequently expected on the imported plants. The Expert Knowledge Elicitation (EKE) indicated with 95% certainty that between 9735 and 10,000 per 10,000 large specimen trees will be free from M. fallax.