Degree Days - A Bit Wet and a Bit Wild

July 15, 2009

By Rich Pope, Department of Plant Pathology

Iowa weather continued to track cool and wet as degree days fell just a bit further behind long-term averages.  With the cooler weather and precipitation since June 1 registering 168 percent of normal, many fields have remained damp.

The wettest part of the state was crop reporting district 1, northwest, where an average of almost 4 inches of rain have fallen since July 1.  Storms with hail and high winds have caused damage in scattered areas, and a few fields are suffering from ponding. These problem areas will hopefully recover as the season progresses. 

Degree day accumulation map for July 12

Many cornfields are starting to tassel, and the bulk of pollen shed and pollination should happen in the next week or so.  

Soybean aphids are being seen occasionally in the northern half and in central Iowa, but remain in general at moderate to low populations. Fields should continue to be monitored for the next few weeks.  


Rich Pope is a program specialist with responsibilities with Integrated Pest Management. Pope can be contacted by email at or by calling (515)294-5899.

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