Soybean Rust Developing Slowly in the United States

Published: July 11, 2008

The current threat of soybean rust in Missouri is extremely low. Soybean rust has only been found on a few soybean leaves at two locations in Florida and nowhere else in the US. Soybean rust has been found on kudzu in several locations in FL and one location each in AL, LA, and TX, but it has developed slowly in these areas. The slow development and spread of rust in the south and southeast parts of the US is due to the drought in these areas. I expect rust to develop slowly in these areas until this weather pattern changes. We recently examined some soybean and kudzu leaves from fields in Missouri and did not find rust. I will present information about the spread of rust on soybean in Missouri and the US on a hotline, 1-866-587-1206, throughout 2008 with new updates daily as rust gets closer to Missouri. More information about the spread of rust in Missouri and the US is available on the Web at http://agebb.missouri.edu/mgt/soyrust/. You may contact me, wratherj@missouri.edu, for more information about this.

University of Missouri Extension has activated its statewide early-warning network of soybean rust sentinel plots/fields during 2008. Each sentinel plot/field will be monitored weekly from June to October. University of Missouri Extension regional agronomists in 20 locations will collect 100-leaf samples from each sentinel plot/field and ship to the pathology laboratory at the MU Delta Center for examination. The objective is to detect soybean rust when it first starts to develop in Missouri soybean fields so farmers can be warned to take action. Once the disease is detected, an all-out alert will be issued using radio and other media.

Missouri farmers and crop consultants may have soybean leaves examined for rust by pathologists at the University of Missouri Plant Diagnostic Clinic. Soybean leaves and a moist paper towel should be sealed in a plastic bag, and these should be sent immediately by express mail to the clinic along with a completed information form. The information form and more instructions about collecting and mailing samples to the clinic are posted at http://soilplantlab.missouri.edu/plant/index.htm. You may also call, 573-882-0623, or email, plantclinic@missouri.edu, the clinic about this and other services they provide. The clinic can also provide diagnosis and management information for other soybean problems including diseases, insects, and weeds. There is a $15 fee for examination of samples submitted to the diagnostic clinic.