Protect Crabapple, Serviceberry, Pears Now From Juniper Rusts

Gymnosporangium rusts are sporulating now on Juniperus hosts.  Look for orange, gelatinous structures on foliage and stems of various Juniperus spp.  They are sporulating both in container production and in the field.  They can be found sporulating when the Cercis canadensis (redbud) begin to bloom, unless it is too dry.

CedarAppleRustJLA                                        Monitor for Gymnosporangium rusts such as Cedar-apple rust (above)

Ced-Haw_Juniperus2JLA                        Cedar-Hawthorn Rust (above)

Cedar-Quince_JuniperusJLA                                                  Cedar-Quince rust (above)

PearTrellisRustJuniper                                and Pear Trellis Rust (above) on Juniperus.

Their spores spread by wind and rain for several km. Protect Rosaceous hosts (e.g. Pyrus, Amelanchier, Malus, Crataegus etc.) before rain or irrigation events with fungicides such as Nova, Pristine, Daconil or Dithane.


To help prevent unsightly Gymnosporangium rusts on Malus (above), Crataegus Amelanchier and Pyrus this summer.


Cedar-Quince rust on Amelanchier fruit, July.

About Jen Llewellyn

OMAFRA Nursery and Landscape Specialist @onnurserycrops
This entry was posted in Diseases, landscape, Nursery Production and tagged , , , . Bookmark the permalink.

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