I have neglected this page a little in the past couple of weeks as things have gotten busy. To ensure continued flow of “goodies” from the clinic, I have assigned a student worker and plant disease enthusiast to post photos of what we saw at the Plant Clinic’s Facebook page. If you have not been there, check us out - http://www.facebook.com/TXPlantClinic.
In the past few days, we have been getting reports and samples of ornamental pear trees with nasty looking black shoots. This is one of the symptoms of a disease commonly known as FIREBLIGHT. Ever wonder why they call this disease that is caused by bacteria – FIREBLIGHT? Apparently, that common name was given to this ailment because of the persistent blackened leaves and appearance on the tree (especially when overlooking a bunch of trees such as in orchard situation) appears as though it was scorched by fire. Did you know that this disease (or at least symptoms of this problem) had been describe as early as 1780. They did not know it was a plant disease caused by a bacterium. That honor goes to Thomas Burrill who reported the causal agent in 1880. If you want to know more about fireblight, see if you can find the USDA Agriculture Information Bulletin #631 which is a bulletin to apple growers. This bacterium is not limited to the pear tree alone, but can infect about 130 plant species in 40 genera. Some potential hosts include the Indian Hawthorn, Loquat, Photinia, Rose, Strawberry.
So check out the Fireblight factsheet for more information about this disease and tips of managing it.