Use the following key to help locate potential causes by following the links which best describe where and what one is observing.
******* DISCLAIMER *******
This by no way covers every disease. This is just a guide. It should cover some of the most common diseases in the US and other countries. Virus diseases are often difficult to distinguish and many exist. Consult a county extension person or garden center for accurate assessment of diseases in your area. This document was developed by Keith Mueller to be used as a guide. The author is not responsible for descisions made by readers regarding the diagnosis or treatment of crops.