Temperatures in the 20s over the weekend in the Upper Midwest caught some later maturity soybeans, effectively shutting down the grain fill process. The news of the frost and the expected impact on yields pushed soybean futures in Chicago on Monday to the highest levels seen since July of 2004.
According to Pella Peterson, an extension agronomist at IowaStateUniversity, between five and 10 percent of Iowa's soybean crop will experience some yield loss due to the early frost. Most of the state's crops are mature enough that significant losses won't be seen. However; wet weather in the spring did delay planting in Northern Iowa, leaving immature beans that were vulnerable to the freeze over the weekend.