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Phytoplasma on rose

What is wrong with my roses?

This was so unusual, I had to photograph it and take samples to UF/IFAS Pathology Diagnostic Center for identification. Initially, they thought the cause was the use of herbicide which typically causes abnormal growth in plants. However, since you assured me there had been no herbicides sprayed on your property, I asked them to look elsewhere.

The pathologists decided to test for phytoplasmas and found them in all the rose leaf specimens. Phytoplasmas are parasitic microscopic organisms which live in the cells of plants and cause various diseases. They are bacterial-like organisms which cannot live outside of living tissue. These phytoplasmas are spread mainly by leafhopper and planthopper insects feeding on the phloem tissues of infected plants. Phloem is the vascular tissue which transports carbohydrates produced in the leaves to other parts of the plant.

In instances of highly expensive plants like palms, it is possible to inject an anti-biotic into the vascular tissue to manage the disease. This injection into a palm tree will require the expertise of a certified arborist. In this case, the UF/IFAS Pathology specialists recommended pruning out the diseased portion and destroying the cut branches.  Do not allow the plant material to remain as litter around the base of the plant as this can provide additional sources of the phytoplasma and disease.

If the whole plant is infected then it is best to remove all the the plant from the landscape.  As it turns out, some of the roses in our demonstration garden were also affected and we will need to remove several of plants too. Very sad.

A special DNA type test must be conducted to detect phytoplasmas in the cells.  These tests are expensive and take special training and time to complete.  The costs of diagnostic tests at the University of Florida run from $40 – $125 each.