Iron deficiency chlorosis (IDC) is a common disease of soybean in Northern States. Most seed companies give a chlorosis rating to their varieties, but companies use different rating scales that confuse farmers. Some seed companies do not provide side-by-side comparisons that can be used by farmers to select varieties most appropriate for their farm. The commercial chlorosis evaluations that are available to farmers are not satisfactory.

These studies are unique; the evaluations involve an adequate number of IDC-prone sites and replications which have proven valuable in creating unbiased IDC scores that are valued by both farmers and the seed industry.