Notes from the Plant Diagnostic Clinic

In the past three weeks, anthracnose infections on a variety of trees have been diagnosed by the Extension Plant Diagnostic Clinic. Anthracnose fungi are active during cool, wet weather. Anthracnose fungi cause spots that are delineated by leaf veins on a number of tree species such as sycamore, maple, oak, elm, and ash. In some trees species, anthracnose infections are not limited to spotting , but also tend to blight the tip of the leaf. For more information about this fungal disease, see the following: http://agebb.missouri.edu/pdc/diagnosticreports/anthracnose01.htm

The clinic has also diagnosed a number of pear, apple, crabapple, and ornamental pear samples with fire blight. This is a bacterial disease that causes a blight and dieback of small branch tips. This is the second year we have seen this problem on ornamental pears such as Bradford pears. For more information see the following: http://agebb.missouri.edu/pdc/diagnosticreports/fireblight01.htm