It is important to be able to recognize the major diseases that occur in landscapes (See Chapter 3 on Disease Diagnosis). Proper disease identification is critical to making the correct disease management decisions. In addition to this publication, there are several other sources of useful information that can aid in developing an understanding of the major diseases of landscape plants. The "Useful References" contains literature with color photographs of disease symptoms on ornamentals, as well as in-depth information on pathogen biology and disease development. Many of these publications also contain excellent color photographs and information about insect pests as well. Developing and maintaining a library of resources such as these provides a valuable tool and should be an integral portion of the disease management program.