Pesticides are often useful in the management of plant diseases when used properly. Pesticides are also frequently used when they shouldn’t be or for the wrong disease. The following is helpful to keep in mind when considering the use of a fungicide:
Four leaf spots are shown below, caused by four types of diseases. We recommend that NONE of these be controlled with Pesticides. Only the anthracnose on ash is caused by a fungus and fungicide applications are not generally recommended for control of this disease on established trees in Missouri.