Corn Hybrid Trials Online

Chad Lee, Extension Agronomist, University of Kentucky

The University of Kentucky corn for grain hybrid trials and corn for silage hybrid trials are online.

The corn for grain trials were planted at seven locations around the state, two of which are irrigated. Hybrids were divided into early, medium, late and white corn tests. The early hybrids were rated to mature by 111 days or earlier. The medium hybrids were rated to mature in 112 to 115 days and the late hybrids were rated to mature at 116 days or later. The report includes yields, test weight, moisture, final stand and lodging. All of these parameters help assess hybrid quality. When possible, yields are averaged across two and three years. The three-year averages across all locations provide the best predictor for hybrid performance next season.

Pay Close Attention to Moisture of Corn for Silage

Chad Lee, Donna Amaral-Phillips and Nick Roy
Extension Agronomist, Extension Dairy Nutritionist and County Extension Agent, University of Kentucky

Milkine is a poor indicator of
whole plant moisture.

The wet August and healthy corn crop are great for tonnage, but will present challenges for determining when to harvest the corn crop for silage. Whole plant moisture is the most important factor for deciding when to harvest corn. Ideal whole plant moistures are 65 to 70% for bunker silos, 62 to 65% for uprights and 62 to 68% for silo bags. Moisture at harvest determines how well the chopped crop will pack which directly impacts the quality of silage when fed-out. Silage harvested too wet will undergo an unwanted fermentation and could limit feed intake and hurt the health of dairy cattle. Plant growth stage is another consideration, but it secondary to whole plant moisture.

2015 Corn Silage Hybrid Report Available

Nick Roy, ANR Extension Agent, Adair County, University of Kentucky
Chad Lee, Extension Professor, University of Kentucky

The 2015 Corn Silage Hybrid Trial is available online. and is linked to the variety testing page.  The test evaluated 20 hybrids submitted by 10 seed companies. A test was conducted in three locations in Kentucky: Green County, Boyle County and Bracken County. All yields were corrected to 35% dry matter. There was a yield difference of 5.9 tons/acre between the highest and lowest yielding hybrid for this. Forage quality tests combined with yield allowed us to estimate milk production for each hybrid. There potential milk production difference from the best and worst performing hybrid was 11,652 pounds per acre. Based on current milk prices, that is worth $2,323 of milk per acre.

Simply choosing the correct hybrids could greatly impact the bottom line. Hybrid selection should always be based off of performance across multiple locations. We encourage you to compare the results from this trial to results from other non-biased trials. If you have questions about this test, contact your local county extension agent.

2015 Silage Performance Test: http://www2.ca.uky.edu/agc/pubs/PR/PR691/PR691.pdf

Corn Silage Trials Available

Chad Lee, Extension Agronomist, University of Kentucky

The 2014 Corn Silage Trials are available online. Twenty-two hybrids were submitted for testing and those hybrids were planted in Boyle County, Casey County and Mason County. University of Kentucky personnel harvested, chopped, weighed,  packaged corn forage samples, analyzed the data and generated the report. Corn forage analysis was conducted by Dairy One.

The first table in the test is the data averaged across all three locations. This is the best data to use for selecting hybrids next season. A combination of corn tonnage and forage quality should be considered when selecting hybrids. Compare the results from this report with other relevant, unbiased silage trials to learn more about hybrid performance. Since half the total forage weight generally comes from the ear, grain trials can also be viewed to gain a better idea about tonnage. Grain trials will not help with forage quality values. County Extension Agents and producers were essential to conducting this test. If you have questions about the test or hybrids, contact your county extension office.

Harvesting very green corn for silage this season

Chad Lee and Carrie Knott, Extension Agronomists, University of Kentucky
Donna Amaral-Phillips, Extension Dairy Nutritionist, University of Kentucky

Farmers are chopping silage at the normal time on the calendar and commenting on the very green corn in the fields. Silage corn was planted late this spring and that delays corn development. The summer was cooler and cloudier than normal, which also delays corn development. Finally, there is a lot of biomass in the corn this year, so drydown may take a little longer. Corn chopping may need to be delayed several weeks this season to get corn to the proper moisture.

Nutrient Removal from Corn Silage Harvest

Edwin Ritchey, Extension Soil Scientist, University of Kentucky

Assumptions made: 

Nutrient removal at standard harvest moisture per ton of corn silage as reported in AGR-1, Table 5:

• Nitrogen = 7.5 lbs/ton
• P₂O₅ = 3.5 lbs/ton
• K₂O = 8 lbs/ton

Pounds of N, P2O5, and K2O removed in silage at various silage yields.
	Amount of Silage Removed per Acre
Nutrient	5 tons/A	10 tons/A	15 tons/A
Nitrogen	37.5	75	112.5
P2O5	17.5	35	52.5
K2O	40	80	120

Greatest removal will be for potash.  Make sure to soil sample if silage is not typically in your rotation, potash removal will be greater than for corn for grain.

Typically, we don’t account for nitrogen removal or carryover to other crops with the exception of wheat.  Usually, wheat following well-fertilized corn should have enough nitrogen for fall growth. With limited nitrogen uptake this year in the corn, nitrogen in the fall for wheat (or other fall-seeded crops) should be sufficient. Monitor wheat growth. If the wheat appears to be N limited, then apply more than 40 lbs N/A in the fall.

Considerations for harvesting drought-stressed corn

Donna Amaral-Phillips, Jeff Lehmkuhler, and Chad Lee

Extension Dairy Specialist, Extension Beef Specialist and Extension Agronomist, University of Kentucky

Remember to consider:
1. If corn is going to be fed as green chop, grazed, or as hay, test for nitrates before harvest to be sure the crop will be safe to feed. For corn harvested properly as silage or baleage and which goes through a good fermentation, nitrate levels could decrease 30 to 50% and can be tested after fermentation and before being fed. If you need to decide which corn fields to harvest as silage or hay, testing before harvesting will allow one to determine which fields need to be harvested as silage (those higher in nitrates) and those with safe levels of nitrates which can be harvested as corn hay. For sorghums and sorghum-sudangrasses, nitrates should be tested before harvest to be safe for your harvest method.

2011 Corn Hybrid Trials

Chad Lee, Extension Agronomist, University of Kentucky

The 2011 Kentucky Corn Hybrid Performance Test is now available online. The test is also linked at the Corn Testing Website. The multiple location average is the best overall indicator for hybrid performance for next season. Look at hybrids that performed near the top (with one least significant difference of the top-yielding hybrid). Hybrids from several companies and hybrids containing several genetic packages did well. Compare the university data to other hybrid tests from independent sources.

The 2011 Corn for Silage Performance Test is also available. This test reports hybrid performance (forage yield and forage quality) for two locations. Again, the multiple location average is the best indicator for hybrid performance for next season.

Planting corn for silage, 2011

Chad Lee, University of Kentucky

email: Chad Lee

Corn silage is a valuable feedstock for many dairy farms and some beef operations. The higher price of inputs this season puts even more pressure on maximizing yield without breaking the bank on inputs. Some of the following guidelines should help with a successful planting season and put the silage corn crop in the best position to reach high yields.

Frost Damage and Corn Silage Options

The recent freezing temperatures essentially stopped corn growth for most of Kentucky. Farmers that had corn planted late for silage are wondering if the corn crop is still suitable for silage. The following is a brief summary, mostly from AGR-183: Late Season Frost-Damage to Corn for Silage.

Corn will ensile well at moisture levels less  than 70% for upright silos and less than 75% moisture for horizontal silos. Corn harvested at 62% to 68% moisture (late-dent stage) is ideal for ensiling.