by OSU Extension 
What are the best ways to manage insects, weeds and plant diseases? Three research-based guides, available through Oregon State University Extension and updated every year, can provide you with reliable answers.
The manuals provide extensive information on pest biology and chemical and nonchemical control methods and are useful to Pacific Northwest farmers and growers as well as consultants and home gardeners.
Starting in 2011, this handbook is updated quarterly, rather than annually, and all information can be found on a new website .
The manual is a quick reference of weed control practices used in Idaho, Oregon and Washington. Chemical regulation of plant growth is complex, and a large portion of the handbook is devoted to registered uses of herbicides, crop desiccants and plant growth regulators.
Most uses of chemical regulators are based on research of the Agricultural Experiment Stations or the OSU Extension Service and neighboring states, where circumstances are similar.
The handbook was originally planned as a manual for county Extension specialists. Information pertaining to only a few crops, sites or situations can be found in publications at local county Extension offices and in the OSU Extension Publications and Multimedia Catalog .
The handbook is revised and reissued annually. More than 50 contributors review management practices for crops in the Pacific Northwest. Chemical and nonchemical control recommendations are included. The web version of the manual, includes links to pest photographs, fact sheets and pesticide labels.
An annual review is necessary as the legal uses of many pesticides change frequently, according to editor Craig Hollingsworth, a University of Massachusetts researcher who is one of several scientists who keep track of the legalities.
“Changes include delisting of crops or sites from the label, new formulations requiring different application rates, restrictions on pre-harvest applications, reapplication intervals or reentry periods or other circumstances,” he said. Many pesticides are restricted for use only by licensed commercial growers. Separate chemical recommendations are listed for commercial and home use.
This handbook is a reference for the important plant diseases in the Pacific Northwest, and much of the handbook’s content can be found online.
The handbook is the primary method for OSU Extension plant pathology to deliver information to producers, agricultural consultants, field scouts, Oregon Department of Agriculture personnel, field and nursery people, master gardeners and chemical industry representatives.
Organic or conventional growers should find the guide useful. General information on disease biology as well as cultural, biological and chemical control recommendations are summarized for each plant disease. Crop diversification, evolving biological systems, new cultural and biological controls and changing chemical control recommendations require continued enhancement of the handbook.
The 2011 handbooks are now available in print and may be purchased from bookstores, or purchase online  or call OSU Extension and Experiment Station Communications at 800-561-6719.