Corn Silage Drydown Seems Right on Schedule Using Days After Silking
September 23, 2004 11(25):164-165
Joe Lauer, Corn Agronomist
Corn development is quite varied around Wisconsin due to planting date and relative
maturity differences. As we enter the fall harvest season, plant moisture will be
a key indicator for the harvest management decision to ensure proper fermenting,
ensiling, and preserving of corn silage.
Early indications for the 2004 corn silage harvest are that plant moisture seems
to be lower than expected using GDU accumulation to schedule harvest. But,
corn silage moisture seems right on schedule using days after silking to project
harvest date.
So far, six counties have reported corn silage drydowns (Table 1) with many reporting
more than one date. Shorter-season corn planted early is often at the proper moisture,
and in some fields, may be past optimum. Corn silage moistures are close to what
was projected at the end of July when we knew silking dates of early planted corn.
This is in spite of the fact that most Wisconsin counties are reporting a significant
lag in GDU accumulation this year, especially during the month of August. Recent
dry weather has somewhat confounded corn silage drydown rate, but total growing
season precipitation through September is normal at most locations.
We have been tracking two corn fields at Arlington. The same full-season hybrid
(105 d RM) was planted either May 5 or May 17. The May 5 planted field is showing
some N stress. On September 7, plant moisture in this field was 71.4%, September
10 = 69.5%, September 14 = 63.5% and September 17 = 65.8%. For the May 17 planted
field plant moisture was 76.7%, September 10 = 78.2%, September 14 = 78.0% and September
17 = 74.8%. The May 5 planted field had decreased 5.6% and the May 17 planted field
has only decreased 1.9%. On September 9, Tom Anderson (Shawano County agent) reported
that some fields were drier than they appeared to be.
In summary, plant moisture of fields is quite variable within a county. Early planted
fields are drying and developing normally. Special attention should be paid to shorter-season
hybrids in early planted fields.
|
Table 1. 2004 UWEX County corn silage drydown results on September 21, 2004. Results
can be downloaded at http://www.cft.uwex.edu/ces/ag/silagedrydown/.
|
|
Dane County
|
Silage Moisture (%)
|
|
Predicted Harvest Date
|
Hybrid Relative
Maturity
|
Planting
Date
|
Sample
Date
|
N
|
|
Min
|
Average
|
Max
|
|
Bunker
/Bag
|
Concrete
Stave
|
O2
Limiting
|
|
Full-season
|
Early
|
26-AUG-04
|
5
|
|
80
|
80
|
80
|
|
Sep 15
|
Sep 25
|
Oct 05
|
|
Full-season
|
Early
|
03-SEP-04
|
6
|
|
77
|
77.8
|
78
|
|
Sep 18
|
Sep 28
|
Oct 08
|
|
Full-season
|
Early
|
10-SEP-04
|
5
|
|
75
|
75.4
|
76
|
|
Sep 20
|
Sep 30
|
Oct 10
|
|
Full-season
|
Early
|
14-SEP-04
|
5
|
|
71
|
72.6
|
74
|
|
Sep 19
|
Sep 29
|
Oct 09
|
|
Dodge County
|
Silage Moisture (%)
|
|
Predicted Harvest Date
|
Hybrid Relative
Maturity
|
Planting
Date
|
Sample
Date
|
N
|
|
Min
|
Average
|
Max
|
|
Bunker
/Bag
|
Concrete
Stave
|
O2
Limiting
|
|
Short-season
|
Late
|
10-SEP-04
|
1
|
|
80
|
80
|
80
|
|
Sep 30
|
Oct 10
|
Oct 20
|
|
Full-season
|
Early
|
10-SEP-04
|
8
|
|
67
|
70.5
|
74
|
|
Sep 11
|
Sep 21
|
Oct 01
|
|
Fond du Lac County
|
Silage Moisture (%)
|
|
Predicted Harvest Date
|
Hybrid Relative
Maturity
|
Planting
Date
|
Sample
Date
|
N
|
|
Min
|
Average
|
Max
|
|
Bunker
/Bag
|
Concrete
Stave
|
O2
Limiting
|
|
Full-season
|
Early
|
31-AUG-04
|
8
|
|
74
|
75.5
|
78
|
|
Sep 11
|
Sep 21
|
Oct 01
|
|
Short-season
|
Early
|
31-AUG-04
|
3
|
|
73
|
74.3
|
76
|
|
Sep 08
|
Sep 18
|
Sep 28
|
|
Full-season
|
Late
|
14-SEP-04
|
1
|
|
80
|
80
|
80
|
|
Oct 04
|
Oct 14
|
Oct 24
|
|
Short-season
|
Late
|
14-SEP-04
|
4
|
|
73
|
75.2
|
78
|
|
Sep 24
|
Oct 04
|
Oct 14
|
|
Full-season
|
Early
|
14-SEP-04
|
39
|
|
61
|
69.8
|
75
|
|
Sep 14
|
Sep 23
|
Oct 03
|
|
Short-season
|
Early
|
14-SEP-04
|
12
|
|
64
|
68.4
|
71
|
|
Sep 11
|
Sep 20
|
Sep 30
|
|
Outagamie County
|
Silage Moisture (%)
|
|
Predicted Harvest Date
|
Hybrid Relative
Maturity
|
Planting
Date
|
Sample
Date
|
N
|
|
Min
|
Average
|
Max
|
|
Bunker
/Bag
|
Concrete
Stave
|
O2
Limiting
|
|
Short-season
|
Late
|
09-SEP-04
|
1
|
|
77
|
77
|
77
|
|
Sep 23
|
Oct 03
|
Oct 13
|
|
Full-season
|
Early
|
09-SEP-04
|
2
|
|
65
|
65.5
|
66
|
|
Aug 31
|
Sep 10
|
Sep 20
|
|
Full-season
|
Early
|
13-SEP-04
|
4
|
|
65
|
67.7
|
71
|
|
Sep 09
|
Sep 18
|
Sep 28
|
|
Full-season
|
Late
|
20-SEP-04
|
3
|
|
68
|
71
|
75
|
|
Sep 22
|
Oct 02
|
Oct 12
|
|
Short-season
|
Late
|
20-SEP-04
|
1
|
|
73
|
73
|
73
|
|
Sep 26
|
Oct 06
|
Oct 16
|
|
Full-season
|
Early
|
20-SEP-04
|
11
|
|
60
|
66.6
|
70
|
|
Sep 14
|
Sep 23
|
Oct 03
|
|
Short-season
|
Early
|
20-SEP-04
|
8
|
|
52
|
62.1
|
66
|
|
Sep 05
|
Sep 15
|
Sep 24
|
|
Pepin County
|
Silage Moisture (%)
|
|
Predicted Harvest Date
|
Hybrid Relative
Maturity
|
Planting
Date
|
Sample
Date
|
N
|
|
Min
|
Average
|
Max
|
|
Bunker
/Bag
|
Concrete
Stave
|
O2
Limiting
|
|
Full-season
|
Late
|
13-SEP-04
|
2
|
|
66
|
67
|
68
|
|
Sep 07
|
Sep 17
|
Sep 27
|
|
Short-season
|
Late
|
13-SEP-04
|
8
|
|
59
|
65.8
|
70
|
|
Sep 05
|
Sep 14
|
Sep 24
|
|
Full-season
|
Early
|
13-SEP-04
|
31
|
|
62
|
69
|
75
|
|
Sep 11
|
Sep 21
|
Oct 01
|
|
Short-season
|
Early
|
13-SEP-04
|
13
|
|
52
|
62.0
|
73
|
|
Aug 29
|
Sep 08
|
Sep 17
|
|
Shawano County
|
Silage Moisture (%)
|
|
Predicted Harvest Date
|
Hybrid Relative
Maturity
|
Planting
Date
|
Sample
Date
|
N
|
|
Min
|
Average
|
Max
|
|
Bunker
/Bag
|
Concrete
Stave
|
O2
Limiting
|
|
Full-season
|
Late
|
09-SEP-04
|
4
|
|
72
|
75.7
|
79
|
|
Sep 20
|
Sep 30
|
Oct 10
|
|
Short-season
|
Late
|
09-SEP-04
|
1
|
|
72
|
72
|
72
|
|
Sep 13
|
Sep 23
|
Oct 03
|
|
Short-season
|
Early
|
09-SEP-04
|
2
|
|
65
|
67
|
69
|
|
Sep 03
|
Sep 13
|
Sep 23
|
|
Full-season
|
Late
|
16-SEP-04
|
5
|
|
64
|
69.8
|
74
|
|
Sep 16
|
Sep 25
|
Oct 05
|
|
Full-season
|
Early
|
16-SEP-04
|
12
|
|
62
|
67.0
|
73
|
|
Sep 11
|
Sep 20
|
Sep 30
|
|
Short-season
|
Early
|
16-SEP-04
|
3
|
|
62
|
67.3
|
73
|
|
Sep 11
|
Sep 20
|
Sep 30
|