So far there have been no indication of temperature trends, but there has been plenty of data about soil moisture levels. Illinois topsoil has moved from 33% short and 64% adequate last week to 48% adequate and 52% short and very short this week. Indiana last week reported topsoil moisture was 36% short and 52% adequate, but this week it is 28% adequate and 71% short to very short. And Iowa last week indicated topsoil moisture was 37% short and 55% adequate, however this week it is 47% adequate and 51% short to very short.
The IL ag economist says another critical factor is planted and harvested acreage, which will be updated on June 29th with USDA’s Planted Acreage Report.
Corn yields are a function of timely planting, which was early this year and should be quite favorable. However, they are also a function of the amount of corn in good to excellent condition toward the end of the growing season, as well as a combination of temperature and moisture through the growing season. So far temperature has not been too far beyond the norms, but soil moisture is short and growing shorter, which is not beneficial to high corn yields.
Source: FarmGate blog