Handling Corn in an "Emergency" Forage Season: Expected Yields
June 24, 2004 11(16):106
Joe Lauer, Corn Agronomist
In eastern Wisconsin, many farmers are faced with an "emergency" forage situation.
Forage inventories will not carry through next winter and forage is needed for their
dairy operation. Last week in the Wisconsin Crop Manager (11:94), Dr. Dan
Undersander summarized a research project evaluating numerous crops for an emergency
season. A conclusion from that project is that corn can produce relatively high
forage yields (2.48 to 9.05 T dry matter/A) even though planted late on July 1.
I would like to follow up on Dr. Undersander's article and report on what can be
expected for corn forage yield at various locations in Wisconsin.
In an emergency season, farmers desire to maximize forage yield. Planting date significantly
affects forage yield in corn with the major effect on grain yield. Table 1 summarizes
all experiments conducted at Arlington involving forage yield response to planting
date. Forage yield of corn planted on May 1 in 1993 was 7.7 T dry matter/A and by
July 1 had decreased to 3.9 T dry matter/A. Over all years corn planted on May 1
has yielded 8.6 T dry matter/A. Corn planted on July 1 has produced 3.2 to 6.8 T
dry matter/A depending upon year with an overall average of 5.1 T dry matter/A.
At locations around Wisconsin, corn forage yield has ranged from 7.1 to 10.1 T dry
matter/A when planted on May 1 (Table 2). Corn planted on July 1 has produced 3.5
to 6.7 T dry matter/A depending upon location. Most of these data were collected
during 1998 and 1999.
Clearly corn is a viable alternative when the objective is to produce "emergency"
forage. On July 1 planting dates, little grain is present in the forage, so forage
quality is dependent upon stover traits. Management decisions that influence quality
in an emergency corn forage situation include: hybrid maturity in relation to fall
frost date, hybrid NDFD trait, and plant density. A future article will discuss
some guidelines for maximizing quality through hybrid selection options for ultra-late
planting dates and changes to plant density recommendations.
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Table 1. Forage yield (T dry matter/A) response to planting date at Arlington, WI.
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Planting date
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Last planting date treatment
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Year
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May 1
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June 1
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July 1 *
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1993
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7.7
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6.5
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3.9
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July 1
|
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1994
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8.5
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6.4
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3.3
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July 11
|
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1995
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7.3
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6.7
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4.7
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July 10
|
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1996
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9.5
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6.9
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6.2
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June 24
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1997
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7.7
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5.6
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3.2
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July 1
|
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1998
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10.7
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10.0
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6.6
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June 25
|
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1999
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10.0
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9.0
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6.6
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June 25
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2000
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8.3
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7.8
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4.0
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June 20
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2001
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9.4
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8.0
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3.8
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June 13
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2002
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8.7
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8.4
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5.1
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June 10
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2003
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8.5
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8.5
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6.8
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June 13
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Overall
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8.6
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7.8
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5.1
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---
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* Forage yield estimated from model when last planting date treatment for experiment
was before July 1.
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Table 2. Forage yield (T dry matter/A) response to planting date in Wisconsin.
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Planting date
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Last planting date treatment
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Locations
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May 1
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June 1
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July 1 *
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Arlington
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8.6
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7.8
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5.1
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July 11
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Ashland
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7.1
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6.3
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3.5
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June 25
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Hancock
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10.1
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8.8
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5.1
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June 28
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Lancaster
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8.0
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8.1
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6.7
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June 24
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Marshfield
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8.9
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7.5
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4.5
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July 1
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Spooner
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8.5
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7.6
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4.4
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June 25
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* Forage yield estimated from model when last planting date treatment for experiment
was before July 1.
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