Chemical companies put considerable investments into efficacy, health and phytotoxicity tests as well as other types of research before releasing a product for use. However, herbicides are designed for efficient use, often in low doses, with the assumption they will be used with reasonable care. Therefore, some of the latest herbicides will cause phytotoxicity in minute amounts. Besides plant injury, be aware of any wildlife which may potentially be at risk. Chemical weed control is usually criticized unjustly when nontarget plants are damaged.
Application errors are normally the cause of widespread damage.
Always read and re-read the label just before applying herbicides. If still in doubt, contact your county Extension agent or chemical company representative for further information before herbicides are applied. Application of herbicides in violation of the label makes the applicator liable for any injury to nontarget plants, people, wildlife, or the surrounding environment. Additional Information Derr, Jeffrey F. and Bonnie Lee Appleton. A Pictorial Guide to Symptom Diagnosis.