Indiana Department of Natural Resources sent this bulletin at 03/25/2022 08:51 AM EDT
Weekly Review for March 25, 2022
This informal report by the Division of Entomology & Plant Pathology is a commentary on insects, diseases, and curiosities division staff encounter on a week-to-week basis. Comments and questions about this report are welcome and can be sent to your respective inspector.
Welcome to the 2022 edition of the Weekly Review. The plan is to put out a couple issues over the next month or so, then publish weekly from May to August. Like always, we love to hear from you so if you have any questions or comments, please reach out to your nursery inspector. As a reminder, the inspector territories map is linked above.
Now the real reason for writing this issue is to tell the industry to be on the look out for bacterial blight in geraniums. We have had a couple suspected or confirmed cases of Xanthomonas hortorum pv. pelargonii (formerly known as Xanthomonas campestris) pop up in greenhouses across Indiana. This disease was introduced on infected propagative material from a wholesaler. If you received a notice from the wholesaler, please be on the lookout!
While symptoms can vary based on the cultivar and growing conditions, this disease can express as water-soaked spots on leaves expanding to yellow patches or brown wedges and lower leaf chlorosis and wilt. Xanthomonas is easily spread by splashing water. This disease only effects plants in the Geraniaceae family with zonal and ivy geraniums (Pelargonium x hortorum and P. peltatum) most susceptible.
If you suspect you have geraniums with bacterial blight, contact your nursery inspector or submit samples to the Purdue Plant and Pest Diagnostic Lab for testing.
