Issue No. 23, Article 9/October 7, 2005
Over-the-Winter Soybean Rust Review
As the season winds to an end, we can be grateful that Asian soybean rust has not yet visited Illinois. I've summarized some materials and programs for this winter season, because Asian soybean rust will continue to threaten soybean production in the United States in the 2006 growing season. This significant disease was first identified in the U.S. in November 2004. Excellent general information can be found at the Plant Health Initiative Web site.
During the 2005 growing season, starting from mid-Florida, rust slowly made its way northward throughout Florida to Alabama, Georgia, Mississippi, and South Carolina. Considerable effort was put into monitoring the spread of soybean rust this past season. Soybean-producing states all had sentinel field plots that were scouted weekly for the presence of rust. This was a successful means of monitoring northward spread of the disease. Numerous first detections were observed in the sentinel plots. USDA will again sponsor the sentinel plot program for the 2006 growing season. Results of monitoring are input on the USDA Asian Soybean Rust Web site. During the growing season, check this site daily. National and local maps and individual state commentaries are regularly updated. Illinois had 37 sentinel plots in 2005 located across the state, with numerous cooperators scouting them; the program will be continued in 2006. University of Illinois Extension also maintains a site with specific soybean rust information for the state. The site addresses disease details, current fungicides, the state soybean rust task force, scouting, and submitting samples.
In Illinois, we will continue to utilize the U of I Digital Distance Diagnostics Imaging (DDDI) system to aid in early detection of Asian soybean rust. The system is essentially an online plant clinic; with regard to soybean rust, our goal is prescreening and early detection. Samples can be submitted at Extension unit offices. The results of your soybean rust prescreening will be available within a few hours. If the prescreening appears suspect, your sample will be sent by overnight mail to the U of I Plant Clinic. Clients will be charged a fee for any mailing costs prior to detection in the state.
Numerous educational opportunities will be available this winter to keep you up to date with Asian soybean rust as it relates to Illinois soybean production. A soybean rust symposium will be offered at the 2006 Crop Protection Technology Conference and at the numerous Corn and Soybean Classics, Regional Extension Crop Management workshops, and local Extension Agronomy Day winter meetings.
U of I Extension has multiple resources to help you scout soybeans in general or soybean rust specifically. They are available online at http://www.PublicationsPlus.uiuc.edu or by calling (800)345-6087. All soybean producers and scouts should have a field crop scouting guide (X880d, Field Crop Scouting Manual, 236 pp., $55). We have also produced a handy soybean disease pocket guide (C1380, Pocket Guide to Soybean Diseases, 47 pp., $14.95) and a disease assessment tool specifically for soybean rust (X881, Soybean Rust Assessment Tool), as well as offering a hand lens that you will need for soybean- rust scouting (X882, Folding Pocket Magnifier, 20X). In season, you will want to check the Bulletin for the latest information on soybean rust, field crop diseases, and other pests; you can also use the Web site search tool for information from prior seasons. The new Report on Plant Disease 1002 "Characteristics of Fungicides for Field Crops" is a good resource for making fungicide decisions.--Suzanne Bissonnette