Aug 4, 2021Minimize hosts of X-disease phytoplasma, habitat for leafhopper vectors
Manage the groundcover in your cherry and stone fruit orchards to minimize hosts of X-disease phytoplasma and habitat for leafhopper vectors.
Clovers, dandelions, curly dock, bitter cherry, and chokecherry are known alternative hosts for X-disease phytoplasma. Grasses appear to be poor leafhopper hosts and are not a host for phytoplasma. Apply broadleaf herbicides to minimize broadleaf weeds (phytoplasma hosts).
Healthy weed-free grass strips compete with broadleaf weeds and supply a non-phytoplasma host environment. Keeping orchards mowed after harvest may also help reduce quantity of alternative X-disease hosts and leafhopper habitat. Some studies have found higher numbers of leafhoppers in less frequently mowed environments in other systems but this has not been studied in cherry orchards with X-disease (Horton 2002, Korosi 2011, Buri 2006).
Consider risk when mowing orchards before harvest. Ideally apply insecticides before mowing to protect trees. When this is not possible (PHI considerations etc) consider your risk. If X-disease prevalence and leafhopper prevalence is low the risk of mowing is likely minimal. If alleyway cover is primarily grass, grasses are not hosts for phytoplasma, so the risk of phytoplasma spread is less likely than when groundcover has phytoplasma hosts.
For more information see http://treefruit.wsu.edu/crop-
Recursos en Español http://treefruit.wsu.edu/
– Washington State University Extension, Tree Fruit Team