Grain Filling Rates in Corn 2010

7/29/2019 Grain Filling Rates in Corn 2010

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extension.umn.edu/cornextension.umn.edu/corn

Grain Filling Rates in CornGrain Filling Rates in Corn

National Crop Insurance Services Regional/State MeetingNational Crop Insurance Services Regional/State MeetingFlandreau, SDFlandreau, SD -- January 5, 2010January 5, 2010

Jeff CoulterJeff Coulter -- Extension Corn AgronomistExtension Corn Agronomist

[email protected]

[email protected]
mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]


2/41

Minnesota AverageMinnesota Average Corn YieldsCorn Yields

0

30

60

90

120

150

180

Yield

(bu/A)

Year

2 bu/A/year increase


3/41

1) Kernels per acre Dependent upon

Plant population

Ear size determination prior to tasseling

Success at pollination (moisture & temp.)

2) Kernel weight

Dependent upon

Rate & duration of grain fill (moisture & temp.)

ComponentsComponents of Corn Yieldof Corn Yield


4/41

LambertonLamberton, 2009, 2009 planted April 24planted April 24

Final plant population (thousands/A)

16 21.5 27 32.5 38 43.5


5/41

44,000 plants/A

4.75 between plants in 30 rows


6/41

Future yield improvement will be related to greaterstress tolerance.

Future Yield ImprovementFuture Yield Improvement in Cornin Corn

What type of stress?

1. Moisture stress (as with high plant populations)

2. Nutrient stress

3. Temperature stress


7/41

1) Kernels per acre

Dependent upon

Plant population

Ear size determination prior to tasseling

Success at pollination (moisture & temp.)

2) Kernel weight Dependent upon

Rate & duration of grain fill(moisture & temp.)

Past & Future Yield ImprovementPast & Future Yield Improvement

in Cornin Corn


8/41

For corn grain appraisals, from the milk stage until

kernels are fully mature & moisture drops below 40%.

Based on weighing ear samples which are groupedaccording to maturity, and converting production to

bu/acre.

Maturity Line Weight Appraisal MethodMaturity Line Weight Appraisal Method

Source: Corn Loss Adjustment Standard Handbook


9/41

Research in Wisconsin & Pennsylvania found that at

early stages of grain fill, the Maturity Line Weight

Appraisal Method resulted in low appraisals when

compared to actual yield at end of the season.

This appraisal method is dependent upon yield

factors for various kernel stages, which are based on

the rate of grain fill.

Maturity Line Weight Appraisal MethodMaturity Line Weight Appraisal Method


10/41

Corn yield is closely tied to crop, weather, & soil

conditions during the rapid grain-filling period.

Thus, factors influencing crop growth before grain fill,

but not during grain fill, often have inconsistent effectson grain yield.

Rapid grain filling in corn occurs from late R2

(blister stage) to late R5 (full dent). Typically 35 to 40 days = 4 to 6 bu/A/day



11/41

Daily grain filling rates & the duration of this period

determine final yield.

Grain filling rates & how they are affected by crop

& weather conditions, are critical to understanding

how grain yields develop.



12/41

Objective: To determine the rate of grain fill for modern hybrids

to provide a better group of yield factors for the

Maturity Line Weight appraisal method.

Corn Grain Filling StudyCorn Grain Filling Study

Lamberton

Waseca

Method:

Weekly ear samples collected

from replicated plots duringrapid grain filling stages.


13/41

Lamberton & Waseca, MN, 2009 following soybean

Nicollet clay loam

2 hybrids with corn borer + rootworm resistance

Pioneer 38P43 (95-day) Pioneer 35F44 (105-day)

4 replications of each hybrid at

both locations

Planted on April 24

Final stand: 32,000 plants/A



14/41

Ear samples were collected weekly from the milk(R3) stage in mid-August through maturity (black

layer)

Additional ear samples were collected throughmid-November to monitor the rate of grain dry

down.



15/41

2009 Rainfall2009 Rainfall


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2009 Air Temperature2009 Air Temperature


17/41

Date of 50% silking (similar at both locations) 95-day hybrid: July 24

105-day hybrid: July 28

Dry conditions following the July 28 silking date

resulted in some pull-back on ears of the 105-day

hybrid.



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August 14August 14 LambertonLamberton, MN, MN


19/41

October 1October 1 LambertonLamberton, MN, MN


20/41

0

50

100

150

200

250

300

223 233 243 253 263 273 283

Corngrain

yield

(bu/A)

Date

105-day

95-day

8/11 10/109/309/209/108/318/21

LambertonLamberton & Waseca, MN: 2009& Waseca, MN: 2009


21/41

0

50

100

150

200

250

300

223 233 243 253 263 273 283

Corngrain

yield

(bu/A)

Date

105-day

95-day

5.5 bu/A/day

4.7 bu/A/day

4.3 bu/

A/day

2.8 bu/

A/day

1.9 bu/A/day

1.5 bu/A/day

8/11 10/109/309/209/108/318/21

LambertonLamberton & Waseca, MN: 2009& Waseca, MN: 2009


22/41

Where is the grain fill occurring?Where is the grain fill occurring?

Base 1/3

Middle 1/3

Tip 1/3


23/41

0

50

100

150

200

250

226 232 239 246 252 260 266 274

Corngrain

yield

(bu/A)

Date

Tip 1/3 of Ear

Middle 1/3 of Ear

Base 1/3 of Ear

8/14 8/20 8/27 9/3 9/9 9/17 9/23 10/1

35%

37%

28%

9595--Day HybridDay Hybrid

(Waseca &(Waseca & LambertonLamberton, MN, MN -- 2009)2009)


24/41

0

50

100

150

200

250

300

226 232 239 246 252 260 266 274 281

Corngrain

yield

(bu/A)

Date

Tip 1/3 of Ear

Middle 1/3 of Ear

Base 1/3 of Ear

8/14 8/20 8/27 9/3 9/9 9/17 9/23 10/1 10/8

24%

36%

40%




25/41

0

15

30

45

60

75

90

223 233 243 253 263 273 283

Corngrain

yield

(bu/A)

Date

Base 1/3 of Ear

Middle 1/3 of Ear

Tip 1/3 of Ear

8/11 8/21 8/31 9/10 9/20 9/30 10/10




26/41

0

15

30

45

60

75

90

105

223 233 243 253 263 273 283

Corngrain

yield

(bu/A)

Date

Base 1/3 of Ear

Middle 1/3 of Ear

Tip 1/3 of Ear

8/11 8/21 8/31 9/10 9/20 9/30 10/10




27/41

0

40

80

120

160

200

223 233 243 253 263 273 283

Corn

grain

yield

(bu/A)

Date

105-day: Base 1/3 + Middle 1/3

95-day Base 1/3 + Middle 1/3

105-day: Tip 1/3

95-day: Tip 1/3

8/11 10/109/309/209/108/318/21

9595-- vs. 105vs. 105--Day HybridDay Hybrid



28/41

Grain Filling Rate by Ear PortionGrain Filling Rate by Ear Portion



29/41

Starch Line Location vs. Grain YieldStarch Line Location vs. Grain Yield

Starch line 20% down on August 3

Starch line 50% down on August 17


30/41

40

50

60

70

80

90

100

110

0 20 40 60 80 100

Yield(% of final)

Starch line (% down kernel)

95-day

105-day

Starch Line Location vs. Grain YieldStarch Line Location vs. Grain Yield


31/41

Starch Line Location vs. Yield LossStarch Line Location vs. Yield Loss

Starch line Yield loss(% down kernel) (%)

20 38

30 2740 18

50 11

60 670 3

80 1


32/41

0

20

40

60

80

100

226 232 239 246 252 260 266 274

%

grain

vs. cob

(dry)

Date

CobGrain

43%

57%

11%

89%

8/14 8/20 8/27 9/3 9/9 9/17 9/23 10/1

Cob vs. Grain (95Cob vs. Grain (95--Day Hybrid)Day Hybrid)


33/41

0

20

40

60

80

100

226 232 239 246 252 260 266 274 281

%

grain

vs. cob

(dry)

Date

CobGrain

46%

54%

13%

87%

8/14 8/20 8/27 9/3 9/9 9/17 9/23 10/1 10/8

Cob vs. Grain (105Cob vs. Grain (105--Day Hybrid)Day Hybrid)


34/41

0

15

30

45

60

75

236 250 264 278 292 306 320

Moisture(%)

Date

Cob

Grain

8/24 9/7 9/19 10/5 10/19 11/2 11/16

0.26%/day 0.33%/day

Cob & Grain Moisture (95Cob & Grain Moisture (95--Day Hybrid)Day Hybrid)


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0

15

30

45

60

75

236 250 264 278 292 306 320

Moisture(%)

Date

Cob

Grain

8/24 9/7 9/19 10/5 10/19 11/2 11/16

0.25%/day 0.42%/day

Cob & Grain Moisture (105Cob & Grain Moisture (105--Day Hybrid)Day Hybrid)


36/41

0

15

30

45

60

236 250 264 278 292 306 320

Moisture

(%)

Date

105-day

95-day

8/24 9/7 9/19 10/5 10/19 11/2 11/16

0.25%/day 0.38%/dayAverage dry-down:

Grain DryGrain Dry--Down (95Down (95-- vs. 105vs. 105--Day Hybrids)Day Hybrids)


37/41

0

15

30

45

60

75

236 250 264 278 292 306 320

Moisture

(%)

Date

105-day

95-day

8/24 9/7 9/19 10/5 10/19 11/2 11/16

0.37%/day 0.79%/day95-day:

105-day: 0.22%/day 0.40%/day

Cob DryCob Dry--Down (95Down (95-- vs. 105vs. 105--Day Hybrids)Day Hybrids)


38/41

Grain filling conditions were good in southern MNin 2009.

The 105-day hybrid yielded 14% more than the

95-day hybrid. Due to more rapid grain fill at the base & middle

ear portions from

Mid-August to early September

Mid-September to October

ConclusionsConclusions from Cornfrom Corn Grain FillingGrain Filling StudyStudy


39/41

The base & middle ear portions make up 75% oftotal yield.

All portions of the ear fill grain at a similar rate.

Kernel starch line correlates well with yieldaccumulation.

This was consistent among hybrids.

11% yield loss with freeze at 50% starch line.



40/41

Cobs dry slower than grain until the grain reachesmaturity.

Cobs are 2/3 times wetter than grain, and thus

can slow grain drying and promote mold if corn isfroze before mature.

Starting in mid-September

1) Grain from 95- and 105-day hybrids dried at a similarrate.

2) Cobs from the 95-day hybrid dried a little faster.



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extension.umn.edu/cornextension.umn.edu/corn

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Grain Filling Rates in Corn 2010

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