Do cold, wet soils increase the risk of soybean seedling disease?

Research can be frustrating. For the past 5 years, my lab has been evaluating seed treatments on soybean. In an effort to detect an effect of seed treatment on soybean stand and yield, in 2015 we planted our trials very early (mid-April). A few days later, it rained, soil temperatures dropped below 50 F and we thought we had nailed it!  Finally we would have great data. Wrong!!! Our ICM News article summarizing these data should be posted to ICM News soon.

Mauricio Serrano, a PhD student in my lab, has taken on the unenviable task of figuring out when seed treatments protect stand. His first question was, does cold stress increase susceptibility to infection by Pythium?  He has been doing trials in a controlled environment. He plants soybean seeds into cups inoculated or not inoculated with Pythium sylvaticum and place the cups at different temperatures.

In answer to his first question, does cold stress increase susceptibility to infection by Pythium, you can see from the above figure that—yes it does. 

Thanks to the Iowa Soybean Association for partial funding of Mauricio's research.

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