Wading through the mire of fungicide information is a mine field lately. To date, using foliar fungicides in soybean production in central Illinois has been virtually non-existent. The introduction of soybean rust to the southeastern United States has changed the fungicide use outlook dramatically. Before you invest any money in fungicides for the upcoming production season, let's be clear about some significant legal and economic issues though.

First let's jump into the legal issues. As you have heard me say at Pesticide Safety Training and testing sessions over the past many, many years, the label for a pesticide is a legal document. That means regardless of if the pesticide is a general or restricted use product the applicator is obligated to follow the label. Fungicides that have a full legal label for use are described as having a Section 3 label. In Illinois we actually have had very few fungicides that have a Section 3 label for use in soybean for control of fungal leaf or stem diseases. A list of these fungicides can be found in the 2006 University of Illinois Agricultural Pest Management Handbook. They are azoxystrobin (Quadris), chlorothalaonil (Bravo and numerous brands), thiophanate-methyl (Topsin-M) and recently pyraclostrobin (Headline).

Why am I bringing this issue up? Well, when soybean rust was identified in the U.S., numerous states applied for emergency use permits for triazole and triazole/strobilurin combination fungicides to control soybean rust. This kind of emergency label is called a section 18. The EPA granted numerous section 18's, for these states including Illinois, thus allowing the use of those products "in soybean, specifically for management of soybean rust". For the most part the section 18's have been granted through 2007. During the interim the EPA would expect that company's who have been granted section 18's would go through and complete the process to apply for full section 3 labels.

So we find ourselves in a bit of an awkward situation in Illinois. As soybean rust gains momentum in the south we are well aware that the probability of infection for Illinois increases. Growers want and need information on these section 3 and section 18 fungicides relevant to Illinois conditions. As a result, researchers and pesticide industry folks initiated research to look at the effect of these many products on soybean rust. The research went forward regardless of the fact the soybean rust did not impact Illinois in 2005. Information gleaned from these studies can be confusing. Some of these products did economically manage current diseases we have in Illinois, some treatments however resulted in economic loss, and some of the treatments were break-even economically. This is interesting from the point of view of managing current Illinois fungal diseases. However, you must exercise caution in adapting these findings to your soybean production. Prior to the actual identification of soybean rust in Illinois, the only fungicides you can legally use to control fungal diseases are the section 3 products I've mentioned above. If you have purchased any of the section 18 fungicides in anticipation of soybean rust, that means you'll be storing them until soybean rust is positively identified in the state, because you can't legally use them to control other diseases in soybean. That announcement will at the time be made by the Illinois department of agriculture. Please check the Bulletin http://www.ipm.uiuc.edu/bulletin/index.php in the next few weeks where I will address current issues surrounding decision making for fungal disease control of both our endemic Illinois diseases and soybean rust.