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Thursday, September 30, 2004

Examining growing season climates in south-central Minnesota

Mark Seeley, Extension Climatologist

As we have been hearing the cold growing season has exposed this year's corn and soybean crops to higher risk of frost damage and more importantly the likelihood of not maturing and being at high moisture content for harvest. Some have referred to their experiences with other similar growing seasons. These are climatically hard to find and not very many in number.

Please find below the ten coldest growing seasons at the University of Minnesota Southern Research and Outreach Center in Waseca, MN. This ranking is based on Growing Degree Days (GDD base 50/86 F) for the May 1 to August 30 period. Also listed are the following September GDD values and the first frost date of the designated year. The parenthetical values are the long term averages.

Thursday, September 2, 2004

The corn crop - frost and maturity

D. R. Hicks, Dept. of Agronomy and Plant Genetics, University of Minnesota

Many corn fields over Minnesota lost some leaves to the frost of Saturday morning August 21. But, except for low areas in some fields, there remains green leaves that can continue to add grain yield. This note gives an update of corn development as the crop moves, albeit slowly, toward maturity. And since some of the crop is not likely to reach normal maturity, this newsletter also gives information regarding the effect of frost before maturity on corn grain yield, dry down, and grain quality.

Corn test weight changes during drying

Dale R. Hicks, Department of Agronomy and Plant Genetics, University of Minnesota

Some of this year's corn crop will not reach normal maturity before the next killing freeze. As a result, maximum yield potential and normal test weights will not occur. Test weights in the low 50's(lb/bu) may be common in some areas the state, especially in the northern half of MN. Test weight can increase with artificial drying if the drying temperature is maintained below 180°F.

Friday, August 27, 2004

Harvesting lodged corn

Dale R. Hicks, University of Minnesota
(revised Sept 1)

We talked about harvesting the wind lodged corn in southwest MN at meetings in Luverne and Adrian and discussed harvesting in one direction and leaving one row unit empty to guide the combine. I have learned a lot about harvesting down corn since then and thought the information might be useful to those with down corn.

Wednesday, August 25, 2004

Harvesting immature corn and soybeans for forage after a killing frost

Paul Peterson, Jim Linn, and Dale Hicks, University of Minnesota Extension Service

Frost touched much of the state's corn and soybean acreage this past weekend. The degree to which the frost was a killing frost varies considerably, but a complete killing frost appears to have been the exception, not the rule. Where frost injury occurred without complete kill, it is too early to consider forage harvest because additional yield and forage quality accumulation is likely from surviving plant parts. However, where these crops were/are completely killed by frost before reaching optimum grain or even forage harvest maturity, harvesting as forage is a viable option. In addition, based on the delayed maturation of corn and soybeans to date, chances are good that there will many acres of these crops that will receive a killing frost before reaching maturity, so harvest as forage may still be one of the better options as the growing season plays out.

Tuesday, August 24, 2004

Drying, handling, & storing wet, immature, & frost-damaged corn

Bill Wilcke, Extension Engineer

Unusually cool growing season weather and early frosts can lead to wet, immature, and frost-damaged corn. This publication describes some of the harvest conditions you can expect after a cold, short growing season and some possible steps to deal with the crops that result from such a growing season.

Monday, August 23, 2004

Early Frost: How common historically and did it end the growing season for some?

Mark Seeley, Extension Climatologist, University of Minnesota

On three consecutive mornings, August 19-21, record or near record low temperatures were reported around Minnesota. Some resulted in damaging ground frosts, while others resulted in a hard freeze, all but ending the growing season for some crops.

Frost on corn and soybeans

Dale R. Hicks, Department of Agronomy and Plant Genetics, University of Minnesota

The growing season continues to be abnormally cold and now the cool temperatures of August 21 have caused frost injury to crops in Minnesota. This report gives an assessment of what I think is the situation.


Damage ranges from all leaves killed on plants completely to the ground in some low areas to very little, if any injury, in other areas or parts of fields. The typical injury for soybeans is only the top leaves killed. For fields that were canopied over, only the top leaves are affected. For fields that were not canopied over, the leaf injury is on the sides and tops of the rows. Typical injury for corn is the top 2 to 4 leaves killed or partially killed.

Wednesday, August 4, 2004

Corn Lodging - What Can We Expect?

Dale R. Hicks, Department of Agronomy and Plant Genetics, University of Minnesota

The extreme winds that occurred in southern Minnesota on August 3rd caused corn to lodge badly. Lodged plants will likely yield lower and make harvesting more difficult.

Will the corn straighten up?

Some stalk straightening will occur, but plants will not completely stand erect. Most of the straightening will occur within the next 2 to 4 days. After that, the plants will not grow upright anymore. Most of the straightening will occur near or above the ear position. The plant will be goose necked. And, ears on goose necked plants will be closer to the ground and higher-than-normal harvest losses may occur. Slower harvest speeds will help to reduce the harvest losses. Lodged plants (and usually in a twisted mass) also increase combine operator fatigue during harvest.

Tuesday, July 27, 2004

Corn Comments: Uneven Plant Height

Dale R. Hicks, Department of Agronomy and Plant Genetics, University of Minnesota

Plant height varies drastically in many cornfields in Minnesota. This has been the case for the past six weeks and is especially noticeable in fields where corn follows corn even though corn following soybean is also extremely variable in height. In some fields the plants are taller in the tractor tracks and tassels are coming out from those plants but not yet visible from other plants. This makes an interesting picture in many cornfields.

Growing degree days - corn growth and yield

Dale R. Hicks, Department of Agronomy and Plant Genetics

Temperature affects crop growth and development. Accumulation of heat during the growing season can be used as a predictor of plant developmental progress. Growing Degree Days (GDD's) is a calculation to express the heat accumulation. GDD's are calculated using the maximum and minimum daily air temperature to determine the average daily temperature. From the average temperature, the base of 50° is subtracted to arrive at the daily GDD's. There are temperature limits used when calculating GDD's because little or no growth occurs when the temperature is greater than 86°F or less than 50°F. So when the maximum temperature is above 86°, then 86 is used as the maximum temperature and when the minimum temperature is below 50°, then 50 is used as the minimum temperature for the day. Daily GDD's are summed for the season beginning May 1.

Wednesday, July 14, 2004

Corn Comments

Dale R. Hicks, University of Minnesota

This growing season is rapidly moving along and it continues to be cold and wet. For most areas of the state the growing degree days (GDD's) are lagging by more than 100 and as high as 300 GDD's in some areas as of July 11. As a result, corn is shorter than it normally is at this calendar date and growth stage. Corn is ten inches shorter than the last 5-year average and 14 inches shorter than it was at this time last year. Will corn height catch up? And will short corn have good yields?

Thursday, March 25, 2004

Early planted corn stands: is pretty the best?

D.R. Hicks, Agronomy and Plant Genetics

We've had a significant portion of Minnesota corn acreage planted prior to May 1 for the past two years (2002 and 2003). In both years, plant stands have not been ideal - spacing between plants has not been uniform and final stands have been lower than expected. Yet both years have been excellent corn production years for Minnesota growers. The state average yield was a record 157 bushels per acre in 2002 and an impressive 146 bushels per acre in 2003.
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