As we head into July we really need some rain. With the early planting season, much of the area corn fields are tasseling. When corn is pollinating it needs a lot of moisture. Add the fact that we are also experiencing some very hot temperatures and the need for rainfall becomes very apparent.
The month of May saw record amounts of rainfall with total amounts in the area varying from 10 to 13 inches. However, during the month of June rainfall slowed down even with the hail storms that we saw in our area.
For generations, the standard measure for corn growth was "knee-high by July 4th," which meant that the corn plant should be able to produce a crop for that year. Of course, most farmers a couple of generations ago had much lower yield goals for their corn than the farmers of today.
Today, "waist-shoulder high" corn by July 4th is a more typical, and has resulted in some very good corn yields in most areas in recent years. It is difficult to get exceptional corn yields in the southern half of Minnesota or in Iowa, if corn is only "knee-high" or smaller on July 4th.
In most of Minnesota and Iowa, the 2012 growing season started out earlier than normal, with most corn planted in April or early May, which got the corn crop off to a good start. Adequate to excessive rainfall in many areas of Southern Minnesota and Northern Iowa during May, along with warmer than normal temperatures, have provided optimal growing conditions for crop development. Most corn in the region will exceed "shoulder-high" by July 4th, with some corn tasseling and pollinating by that date, which is well ahead of normal, and far ahead of corn development a year ago.
Corn and soybean development in most areas is well ahead normal, due to the warmer than normal temperatures during much of the early growing season in 2012. The accumulation of "growing degree units" (GDU's) in 2012 at the U of M Southern Minnesota Research Center totaled 947.5 GDU's from May 1 through June 28, which compares to a normal accumulation of 830 GDU's by June 28. By comparison, the GDU accumulation on June 28 was 792 GDU's in 2011; 847 GDU's in 2010, and 774 GDU's in 2009. The 2012 GDU accumulation is about 12-15 percent ahead of normal at most locations in southern and western Minnesota, which correlates the crop development being 7-10 days ahead or normal development.
Large areas of west central and east central Minnesota also had considerable crop damage from hail and strong winds, in addition to the heavy rainfall amounts, resulting from several severe storms in mid-June. Except for the crops that were damaged by the heavy rainfall and severe storms in May and June, most of the corn and soybeans in the southern half of the state look good to excellent. However, there is a growing concern in some locations across the southern one-fourth of Minnesota with potential crop damage from the continued dry weather pattern and very warm temperatures.
As of June 28, about 70 percent of the main corn and soybean producing areas in the U.S. were listed as suffering some drought symptoms by the "National Drought Monitor." Large areas of Illinois, Indiana, Ohio, Missouri, and Kansas were listed as having "moderate" to "severe" drought conditions. Growing areas in Iowa, Nebraska, and South Dakota were listed as "abnormally dry" to "moderate drought". Only the Upper Midwest, including most of Minnesota, was considered to be "drought free."
(Kent Theisse Minnstar Bank, Lake Crystal contributed to this article.)