Here it is June again. Soybean are up and progressing well. As you are aware, unprecedented effort has been extended these past three years to drive home the point that scouting your soybeans is going to be essential to manage soybean rust. Having spent a fair amount of time out on the road discussing soybean rust management and plans in the state I also know that many of you still need to make a commitment to actually scouting yourself or to hire the scouting of your soybeans. Doubtless many of you are suffering from information overload, so let's get down to the basics of how to scout for rust in soybeans.

First you will need a 20X hand lens, some zip lock plastic bags, some paper towels and an indelible maker. To use a 20X lens, place the lens at your eye and bring the leaf you are examining up to the lens, this is backwards from how you use a 10X lens. Try doing a Google search on '20X hand lens' and several geological survey sites should come up or try Edmund Scientific, or you can get one through U of I PubsPlus or another vendor of your choice. I also recommend that you get a good scouting guide because you are going to see a whole lot of other things out in the field aside from rust; obtain the Illinois Field Crop Scouting Manual X880d as a guide to your efforts. I also recommend our handy soybean disease pocket guide (C1380 Pocket Guide to Soybean Diseases) and specifically for Soybean rust a disease assessment tool (X881 Soybean Rust Assessment Tool X882). Order them online or call 800-345-6087.

It will be important for you to recognize the symptoms of soybean rust. Soybean rust doesn't look like your average common field corn rust; the color and location on the plant are different. There are 2 types of lesions you may see on the bottom of a leaf as the disease begins. First is a pustule that looks like a little volcano with a 20X hand lens and will have tan spores that are produced from the top of the pustule. The second may be a reddish brown lesion with no spores evident, also on the underside of the leaves. Soybean rust shows up on the bottom of the plant first and not on top. Soybean rust symptoms are fairly similar to symptoms of two common diseases we see in Illinois. The reddish lesion may mimic Septoria brown spot and the pustules may mimic the pustules of bacterial pustule. Careful observation of these types of symptoms will be very important for early detection and identification of the disease in the Illinois this year.

Begin your weekly scouting as the soybeans enter their late vegetative stages of development. Once a week, in one contiguous field, scout 5 locations in a zigzag pattern observing 20 plants in each of the 5 locations. Soybean rust starts on the bottom of a plant so you will need to carefully look at the bottom of the plant, and look at the bottom of the leaves on the bottom of the plant.

If you see something that looks "suspect" for soybean rust – follow this simple protocol. Collect 20 leaflets with suspect symptoms. Leaflets should be flat, dry, and placed between dry paper towels. Leaflets should be packaged in two layers of zip lock plastic bags. The bags should be clearly labeled with a permanent marker providing: date, host plant, collector's name, phone number, appropriate supervisor/DSM contact information, collection location within the field, location of the field, county, township & section, and nearest intersection. GPS information is helpful if available.

Submit samples to the University of Illinois' Distance Diagnostics through Digital Imaging (DDDI) system located at your local county Extension Unit Office. The results of your soybean rust prescreening via DDDI should be available within a few hours. If the DDDI prescreening appears suspect, your plant sample will be submitted to the U of I Plant Clinic. The Illinois Soybean Association (ISA) will pay your plant clinic fee if you utilize the DDDI prescreening. However, overnight mailing fee will be charged to you for mailing costs prior to first annual detection in the state. Following confirmation of soybean rust in your area, scout soybean fields using the same protocol and sample submission procedures. However, overnight delivery will not be required and all testing will be done within the state. You may submit samples directly to the University of Illinois Plant Clinic for a $12.50 fee but we are using the county Extension Units as points of entry to attempt to minimize the number of false samples so the process of detection and identification can run as efficiently as possible.

In suspect areas increase your scouting to every three days. To get the most up to date commentary on the spread of rust in the soybean growing states and in Illinois you will want to monitor the national USDA soybean rust website at http://www.sbrusa.net/. You can also find information localized to Illinois at http://www.soybeanrust.org/.