The very warm growing season this year has pushed the 2012 corn  crop very rapidly toward maturity. Corn harvest  has begun in many areas of south-central and southwest Minnesota. The corn moisture content is in the 20-25% range on early-planted corn, which is more typical of early October conditions. Corn yields in 2012 are expected to be quite variable across southern Minnesota, depending on timely rainfalls, soil types, planting date and corn hybrids. So far, the early corn yields in many areas have been pleasantly surprising, considering the extremely dry conditions that existed throughout most of July and August across the region.
While some of the early reported corn yields have been better than expected, there will likely be a wide variation in corn yields in south-central and southwest Minnesota by the end of harvest. Areas that received less rainfall and have lighter soil types are expected to have lower yields. Some areas of northern Iowa that received very limited amounts of rainfall are reporting early corn yields in the 80-125-bu./acre range. Corn yields are expected to be stronger and more consistent in areas of southeastern and central Minnesota that received more timely rainfalls during the growing season.
Much of the corn in southern Minnesota has now reached physiological maturity (black layer) and has begun to dry down in the field. Corn is usually at 30-32% moisture when it reaches back layer, and ideally growers like to see corn dried down in the field to 20-22% moisture, or lower, before harvest. This greatly saves on corn drying costs, and improves the quality of the corn being harvested and going into storage. Corn is usually dried down to a final moisture content of 15-16% moisture for safe storage until the following summer. Corn will dry about 0.50%/day naturally at an average daily temperature of 60° F, which increases at temperature levels that have existed in early September. At Waseca, Minn., the normal daily average air temperature in September is above 60°, but that drops to about 48° during October.
Due to the very warm, dry weather during the last half of the 2012 growing season, along with the rapid maturing process of the corn crop, there has been some concern for the potential of low test weights with the 2012 corn crop. The standard test weight for corn is 56 lbs./bu. Thus far, corn test weights have not been an issue during the early portions of corn harvest in the region, with most test weights being reported at 55-58 lbs. This could change as we get further into to the harvest season.
Another concern with the 2012 corn crop in some areas is stalk quality and strength. Some corn has damaged by strong winds and hail earlier in the growing season, which has lead to weaker stalks and late-season development of stalk rots. Some agronomists also feel that the very warm growing season, which caused the corn to mature quicker than normal, may have also lead to weakening of stalks in some hybrids across the region. Growers in affected areas should be monitoring their fields for potential problems, and adjusting their 2012 harvest schedule accordingly.
The 2012 soybean crop is also maturing rapidly in most areas, with most soybeans now turning color and dropping leaves. Full-scale soybean harvest is likely to be initiated in many parts of southern Minnesota by Sept. 15-20. Soybean yields are also expected to be highly variable across southern Minnesota, again with a bit more consistent yields in southeastern and central portions of the state, due to more frequent rainfall during most of the 2012 growing season.
As we enter full-scale fall harvest for the 2012 growing season, it is a good time for farm families to review the farm safety procedures for their operation. More farm accidents occur during the fall than at any other time of the year, and usually involve one or more family members. Special care should be taken with children and senior citizens around farm and grain handling equipment, as these groups are the most vulnerable to farm accidents.
The non-farm public also needs to pay extra attention when driving on rural roads during harvest season, especially before and after work or school. Farm vehicles are larger and move much slower than cars, and the autumn sun is usually in a bad position during the times of heaviest traffic in the mornings and late afternoon on rural roads throughout the fall season. The best advice is to slow down, pay attention and stay off the cell phones while driving.
Editor’s note: Kent Thiesse is a former University of Minnesota Extension educator and now is Vice President of MinnStar Bank, Lake Crystal, MN. You can contact him at 507-726-2137 or via e-mail at [email protected]