Many farm operators in south-central Minnesota got a reminder on June 20 and 21 of just how fragile crop growing weather conditions can be in the Upper Midwest. Crop conditions in south-central Minnesota have been almost ideal for the first two months of the 2007 growing season, from mid-April to mid-June, resulting in some of the best looking corn and soybeans ever for this stage of the growing season. However, in a matter of minutes of Wednesday evening, June 20, and Thursday afternoon, June 21, the prospects for the 2007 corn and soybean crop changed dramatically for dozens of farmers in the region, as a result of two separate major hailstorms. The June 20 hailstorm impacted 10,000 -15,000 acres of cropland in LeSueur County, resulting in moderate to very severe hail damage, with additional hail damage in Sibley, Waseca and Steele counties. The June 21 storm caused another 15,000-plus acres of crop damage in western and southern Blue Earth County, as well as parts of northern Faribault County, again resulting in some quite severe hail damage to corn and soybeans in portions of the area. Farm operators and crop insurance adjusters are evaluating crop damage, reviewing crop insurance coverage and looking at any potential for replant options. This late in the growing season, replant options are limited to very early soybean varieties, with a yield potential of 25 bu./acre or less. For most producers with multi-peril crop insurance and hail insurance, the best option will probably be to hope for good recovery on the crops that received light to moderate hail damage, and to allow the crop and hail insurance coverage to pay indemnity payments for crop losses on the more severely damaged crops. However, the insurance payments will not offset the excellent yield potential that existed with most of the 2007 corn and soybean crop that was damaged by the hail.

Many farm operators in south-central Minnesota have commented that the early season growing conditions in 2007 are the best that they have seen since 1981. The June 21 hailstorm in Blue Earth County was a reminder of one of the worst hailstorms in Minnesota history on June 23, 1981. Nearly 100,000 acres of corn and soybeans in Blue Earth County were totally destroyed by the severe hailstorm on that day, plus considerable property damage in the county. Several other counties in the Minnesota River Valley and in Southern Minnesota were impacted by that severe hailstorm in 1981. The hailstorms last week in South Central Minnesota did not approach that magnitude; however, the crop damage from the 2007 storms is quite severe in some areas.

Knee High By July 4

For generations, the standard measure for corn growth was “knee high by July 4,” which meant that the corn plant should be able to produce a crop for that year. Of course, most farmers a generation or two ago had much lower yield goals for their corn than the farmers of today. In recent years, “waist high” or highercorn by July 4 has been more typical, and has resulted in some very good corn yields in most areas in recent years. It would be difficult to get exceptional corn yields in southern Minnesota if corn is only “knee high” or smaller on July 4. This year, nearly all the corn in southern and western Minnesota will be over “head high” by July 4, with a considerable amount of corn starting to tassel. Most of the 2007 corn crop is well ahead of normal corn development for late June and early July, mainly due to above-normal temperatures and accumulation of “growing degree units” (GDU’s) from late April through late June. Most of southern Minnesota has been running 15-20% ahead of normal for GDU’s since late April. Adequate moisture and the rapid accumulation of GDU’s during June have also allowed for good to excellent growing conditions for the 2007 soybean crop in most of areas. However, June rainfalls have been variable across the region, and there are areas of southern Minnesota that remain quite dry, even with recent rainfall events.

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 kent.thiesse@minnstarbank.com.

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