University of California, Davis
- Information that aids in disease diagnosis of a number of crop plants, proper sampling procedures for submission to diagnostic labs, and the principles of epidemiology and disease management.
- http://plantpathology.ucdavis.edu/ext/index.htm

Pennsylvania State University - Plant Pathology Fact Sheets
- Provides diagnosis and control measures for common diseases of ornamental plants frequently grown in the northeastern U.S.
- http://www.ppath.cas.psu.edu/EXTENSION/PLANT_DISEASE/

Alabama Cooperative Extension System - Publications
- Searchable information on diseases of cotton, fruits, ornamentals, peanut, turf, vegetables, and wheat.
- http://www.aces.edu/publications/

Virginia State University
- Disease fact sheets listed by type of plant including field crops, vegetables, herbaceous ornamentals, and woody shrubs and trees.
- http://www.ext.vt.edu/pubs/plantdiseasefs/

University of Idaho
- Information on plant diseases affecting local crops including barely, beans, corn, sugar beets, potato and wheat.
- http://www.uidaho.edu/ag/plantdisease/home.htm

North Carolina State University
- Notes on disease identification and control for alfalfa, corn, cotton, fruits, nuts, ornamentals, soybeans, tobacco, turfgrass and vegetables.
- http://www.ces.ncsu.edu/depts/ent/clinic/indexa.html

Texas University
- Description and control of a large range of diseases of crops, turf, ground covers, shrubs, trees and flowers.
- http://plantpathology.tamu.edu/Texlab/index.htm

Ohio State University
- Information and control for a range of common diseases.
- http://ohioline.osu.edu/hyg-fact/3000/index.html

University of Arizona
- Information and pictures of plant diseases (listed by crop or plant common name), disease publications, newsletter and related links.
- http://ag.arizona.edu/PLP/plpext/index.html

University of Illinois
- Description and control of some common tree diseases.
- http://www.urbanext.uiuc.edu/focus/

Oklahoma State University
- Description and control of a variety of plant diseases including those caused by insects.
- http://www.ento.okstate.edu/factshts.htm#plantpath

University of Florida
- Description and control practices of crop, citrus, fruit, ornamental, turf and vegetable diseases commonly occurring in the local region.
- http://plantpath.ifas.ufl.edu/takextpub/default.htm