Spread model for kiwifruit bacterial canker
A suitable tool
The spread model for kiwifruit bacterial canker Pseudomonas syringae pv. actinidiae (Psa) was carried out with a dispersal kernel derived from a 2Dt-distribution developed in the EU project PRATIQUE. The results were compared to the spread history of this pest in Europe to validate the applicability of the model. The dispersal kernel was already tested on insects, plants, nematodes and one fungi, but hitherto not on bacterial pests. Despite some bacterial characteristics which complicate the parameter settings, the model provides a suitable tool for spread modelling of bacteria with few key parameters. The spread model of Psa was presented in the Joint EFSA-EPPO Workshop “Modelling in Plant Health” in Parma from 12.-14 December 2016 (https://www.efsa.europa.eu/de/events/event/161212), and a publication is in preparation for the EPPO Bulletin.
Figure 1: Modelled spread of Psa over 4 years after introduction (t=0) with an assumed irrigation scenario in the summer months and a high proportion of human assisted long-distance spread (shape parameter p=5). Population abundance (% of carrying capacity) shown in graduated colours from white (Nt < 10-6 %) to yellow, orange and red (Nt ≥ 10%), grey means no data.
Gritta Schrader and Anne Wilstermann