FEW TOPICS in the past have dominated the winter farm shows like Asian soybean rust. I'll bet there's not a single farmer in the Midwest who hasn't heard of the disease by now. What's remarkable is how rust has monopolized magazine coverage and dominated ag conferences and coffee shop sessions. We all know more about this fungal plant disease, which has barely entered the Midwest, than we know about soybean cyst nematode and other common pests that have hindered soybean yields for years.
Based on what I've privately heard from farmers, many of you already have stocked up on fungicides. A few chemical company reps unofficially confirmed this trend and say they expect to start selling fungicides on an allocation basis only — only to their best customers. Sprayer and nozzle companies also report brisk business.
Helping feed the rust shopping fever is the great year most growers experienced in 2004. If it had been a lousy year, wallets would have been buttoned up tight.
So with all the worrisome publicity, will rust live up to its billing? Maybe, maybe not. Soybean expert Palle Pedersen, Iowa State University Extension agronomist, says he is more concerned about soybean cyst nematode, white mold and aphids this year than rust. And this comes from someone who just traveled to Brazil to help train Iowa agronomists for rust identification.
Pedersen says rust is very dependent on rain. It rains every day in some parts of Brazil's soybean region. Brazil also provides a continuous growing season without a killing frost, which confounds rust control programs.
Other off-the-record conversations tend to support the idea that rust may not make as big an impact this year as some of the hype leads us to believe. Winter frosts in the South killed most of the kudzu where rust overwinters. It may take a timely hurricane to send the spores back into the South and up into the Midwest.
However, everyone should understand that rust is aggressive and know what the treatment options are for an infestation, should it occur (see “Be prepared,” page 72). If it doesn't, growers scouting for rust may find other yield-robbing problems like aphids and white mold.
On the positive side, soybean growers will now spend more time scouting their fields. This should help them spot other problems like aphids and white mold. It could make 2005 a banner soybean year.