Friday, November 12, 2021

2021 Wisconsin Corn Hybrid Performance Trials: Grain • Silage • Specialty • Organic


Every year, the University of Wisconsin-Extension and the University of Wisconsin–Madison College of Agricultural and Life Sciences conduct a corn evaluation program in cooperation with the Wisconsin Crop Improvement Association. The purpose of this program is to provide unbiased performance comparisons of hybrid seed corn for both grain and silage available in Wisconsin. In 2021, grain and silage performance trials were planted at 14 locations in four production zones: the southern, south central, north central, and northern zones. Both seed companies and university researchers submitted hybrids.  

The 2021 growing season at most sites was warmer compared to the 30-year normal. Growing season precipitation compared to the 30-year normal was drier for southern Wisconsin and average for northern Wisconsin. Planting progress was faster than average with 50% of the acreage planted by May 3. Most trial plots were established by early May. Stand establishment was good to excellent at all locations. A late spring frost event on May 30 reduced some plant stands in commercial production fields. In southern Wisconsin, precipitation was lower than normal prior to pollination and during early grain-filling. However, there was just enough precipitation to carry plants along and little stress was observed visually. Ear size was larger than normal. Tar spot, Phyllachora maydis, was significant in southern Wisconsin and disease ratings were obtained at Arlington. Isolated incidents of Anthracnose, Colletotrichum graminicola, was observed in northern Wisconsin. Both diseases showed up late in the growing season and likely did not affect silage yield. Good growing conditions continued into late-fall with a killing frost occurring in late October. Silage and grain moisture was lower than normal. Little plant lodging occurred at most trial sites. Little disease and insect pressure were observed within most trials. 

Results for the 2021 growing season can be found at:

Other years can be found at:

2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 | 2013 | 2012 |

Thursday, October 21, 2021

How Dry was the 2021 Growing Season at the Arlington UW-ARS?


This year, southern Wisconsin experienced dry conditions during the growing season. In spite of low precipitation, corn grain yields have been good to excellent for most farmers in the area.

The University of Wisconsin Agriculture Research Station (UW-ARS) at Arlington began collecting weather data in July of 1962. How did the 2021 growing season compare to the previous growing seasons at Arlington for precipitation? 

Growing season (April 1 to October 31) weather data (1963 to 2021) were obtained from the Midwest Region Climatological Center for the UW-ARS at Arlington. A 58-year average was calculated along with the standard deviation of the mean. The standard deviation was multiplied by 1.25 to get the wettest and driest growing seasons over this time period. The accumulated precipitation was compared to the average for each day during the study period. The daily deviations from the average accumulated precipitation are shown in Figure 1.

The wettest growing seasons during this time period were 2019, 2018, 2010, 2008, 2006, 1993, and 1980. The driest growing seasons were 2012, 1988, 1976, 1971 and 1963 (click on each year to see a more detailed weather summary). The 2021 growing season ranks as one of the driest on record for the UW-ARS at Arlington. Precipitation patterns can be localized varying dramatically even within a farm.

In spite of being one of the driest seasons on record, grain yield of the UW Corn Hybrid Performance Trial averaged 254 bu/A (see preliminary results here).

Figure 1. Seasonal precipitation deviations from April 1 to October 31. Years were selected using +1.25 standard deviation of the 58-year average.

Record grain yield years usually have the following characteristics:
  1. Earlier than normal planting with adequate spring soil moisture to activate herbicides,
  2. A mild moisture stress ("mini-drought") during early corn development that fosters deep root penetration into the soil profile with soil moisture eventually replenished to normal levels by pollination (1-inch of precipitation per week),
  3. Corn development typically ahead of normal at some point during the growing season, 
  4. A fall killing frost at the end of September or during October, and 
  5. Dry fall harvest conditions.

The 2021 growing season  was typical of a record year, except that corn was challenged with a late-May frost event, rainfall of less than 1-inch per week during July to September, and a late incidence of Tar Spot. The lesson I learned from this season is that corn could get by with less than 1-inch of rain per week during July to September and still yield well. The efficient use of water might be attributed to the European Corn Borer transgenic trait grown in most modern hybrids.

Preliminary Grain Yields for the UW Corn Hybrid Evaluation Trials

Grain corn is rapidly being harvested across Wisconsin. Many farmers are reporting good yields at relatively dry grain moisture.

Preliminary grain yields of hybrids in the UW Corn Performance Trials averaged 224 bu/A at 22.3% moisture (Table 1). The highest yielding location was Fond du Lac at 260 bu/A. Good yields were reported at most sites in northeastern Wisconsin. Test weight ranged from 53 to 57 lb/bu. Little lodging was observed, although plant stalk quality is an issue. Hopefully high winds will continue to stay away through the rest of harvest. Tar spot was a significant disease at locations in the southern zone.

Table 1. Preliminary Grain Yields for the 2021 UW Corn Hybrid Evaluation Trials.

Final results will be available in November. Watch for the 2021 results at

Tuesday, October 19, 2021

Preliminary Silage Yields for the UW Corn Hybrid Evaluation Trials

Corn harvest is well underway with 32% of Wisconsin corn acreage harvested for grain as of October 17 (USDA-NASS). Corn is mostly mature (96%) with 68% good to excellent.

Preliminary corn silage yield for hybrids in the UW Corn Hybrid Evaluation program averaged across all locations was 10.6 T DM/A at 62.9% forage moisture (Table 1). Good yields were observed in spite of drought conditions at many locations. The highest yielding location was Arlington at 12.0 T DM/A averaged across 195 plots. 

Corn silage drydown was faster than normal. Two weeks prior to harvest, we inspected all trials and determined a typical start-date for harvest. However,  forage moisture proved drier than normal at many sites, although the overall average of 62.9% which was close to our target moisture of 65%.

  Table 1. Preliminary Silage Yields for the 2021 UW Corn Hybrid Evaluation Trials.

Table 1. Preliminary Silage Yields for the 2021UW Corn Hybrid Evaluation Trials.
We are currently grinding and running forage quality analysis on all samples collected. Final results will be available in November.

Friday, June 4, 2021

Frost During Early Corn Development and its Effect on Yield

Photo by Kent Kohn

This morning I received a series of texts from a crop consultant whose clients were concerned about the effect of last Friday's frost on corn yield. The question was, "Should they replant?" The short answer is "No." This frost event was a relatively early, correctable event that has caused a lot of anxiety, especially with above average corn prices. However, it is best to be patient. The growing point for corn is below ground and is often well insulated from freezing temperatures.

Most plant leaf damage caused by the recent frost is observed in fields with lighter soils, that were no-till, that had cover crops, and/or were along edges of waterways. Most plants are recovering with new leaves emerging, although the recovery process has been slower than I anticipated. With temperature forecasts in the 90s, new leaves should emerge. If new leaves do not appear, then the plant has died. This does not mean that the field must be replanted. Use decision guidelines from the UW publication, "Corn replant/late-plant decisions in Wisconsin."

Although last week's frost killed emerged corn leaves, the effect on yield will be negligible. By now, nearly a week after the frost, corn plants should be showing newly emerging leaves. There may be some tie-up of the leaves with the killed leaves, but eventually these newly emerged leaves will unfurl, and development will continue normally. 

Through the years we have done numerous leaf clipping studies where we have removed 100% of the leaves and measured its effect against an untreated check. In most years, corn grain yield was not affected when 100% of plants were defoliated between V1 and V4. On average there was a 7% yield decrease, however, the effect was significant in only 2 of 7 years that the experiment was conducted. Additionally, hail adjuster tables do not even begin adjusting for yield until the V7 stage of crop development.

Figure 1. Grain yield response of corn that was 100% defoliated between V1 and V4 at Arlington, WI.

Further Reading

Corn Replanting.