2007 Virginia Tech Corn Silage Hybrid Evaluation Program

Brian JonesAgronomy Extension Agent

Outline

The 2007 growing season in review Go over corn silage publication Introduce a helpful software tool

Growing Season in Review April began cool and wet, but ended

with warmer than average temperatures

Planting was generally ahead of schedule around most of the area

By mid-June, 40% of counties (including Rockingham and Augusta) reported being short of soil moisture

You know the rest…hot and dry just about everywhere

Growing Season in Review Augusta and Rockingham Counties

declared drought disaster areas Hot temperatures and no rain before

and after silking severely affected yields

Some areas did receive timely showers and I have seen extremes in corn yields

Good year to really test hybrid performance!

2007 Corn Silage Hybrid Performance Trials

Corn Silage Test

69 Hybrids from 11 Companies Down from last year More hybrids entered across locations

This is GOOD: Better DATA

4 locations 2 on farms (Special Thanks) 2 on experiment stations

Shenandoah Valley Test Details Hosted by the Phillips’ Family North Point Farms Soil Type: Frederick-Christian Silt Loam Planted April 30, 2007 Weed Control (April 26)

Preplant: 1 qt Roundup + 1 qt 2,4-D + 1 qt Aatrex + 3 qt Lumax + 1 qt Princep

Insecticide: 4.5 lb Force 3G at planting Fertilizer:

Preplant: 6000 gal slurry March 12 Planting: 17 gal 20-10-0-2.2S-.127B-.25Zn

Plot size: 2 30” rows x 25’ with 4 replications Seeding rate: 25,000

Shenandoah Valley Test DetailsHarvested August 23rd

THANKS TO:CHARLIE FRETWELL, ALL THE AG AGENTS!

Plots were sub-sampled for quality analysis performed at the Southern Piedmont Experiment Station.

MILK 2006 was run on the data.

Let’s Look at the Data Table 1 – Hybrid Information

Key Points: Sorted alphabetically (pick up corrected handout) IST/GT = insectide seed treatment or genetic

traits Number of different treatments this year to

compare DTM = days to maturity

As provided by the companies OBS = very important!

MORE OBSERVATIONS = MORE RELIABILITY

Tables 2, 3 and 4

Use these to COMPARE and PREDICT yield and quality

Table 2 = Yield (ton/acre) Table 3 = Quality (milk/ton) Table 4 = Yield x Quality

(milk/acre)

Tables 2, 3 and 4

Key Points: Values listed are RELATIVE

What does Relative mean?

Comparing actual numbers not appropriate Does not account for differences in sites

Levels the playing field A percentage:

RelativeYield = Yield/AverageYield * 100 100 = average >100 = above average <100 = below average

Tables 2, 3 and 4

Key Points continued Values listed are RELATIVE Look at the multi-site average

A good hybrid will perform above average over all sites and conditions

Remember: Every farm is different! Weather is not consistent!

Tables 2, 3 and 4

Key Points continued Values listed are RELATIVE Look at the multi-site average Look at the number of observations

MORE OBSERVATIONS = MORE RELIABILITY

Tables are ranked first by observations, then by multi-site average

Tables 2, 3 and 4

Key Points continued Values listed are RELATIVE Look at the multi-site average Look at the number of observations Look for astericks (*)

Indicate values that are significantly high

Tables 2, 3 and 4

Key Points continued Values listed are RELATIVE Look at the multi-site average Look at the number of observations Look for astericks (*) Look for shading

CONSISTENTLY high performers in that table

QUESTIONS?

Tables 5 through 7 Shenandoah Valley data ACTUAL instead of RELATIVE data QUALITY data found here Use to compare hybrids at one site only! Table 5: 2007 values Table 6: 2 yr average Table 7: 3 yr average

Tables 5 through 7

Key Points Look at DTM and DM at Harvest

Check DM before harvesting Maturity ratings differ between

companies!!

Tables 5 through 7

Key Points Look at DTM and DM at harvest Look at nutritional analysis

CP, ADF, NDF, etc. Milk2006 lb milk / acre

This tells you if the hybrid can milk as well as yield

Very important information!

Milk2006 Output

Caution: For comparing forage samples/hybrids

NOT for predicting actual milk production Use statistics

Keep magnitude of differences in perspective

“Is milk per acre difference of 1,000 lbs meaningful?”

Use statistics and LSD to guide you…

Tables 5 through 7

Key Points Look at DTM and DM at harvest Look at nutritional analysis Look at the statistics

Sound Methods

Statistical analysis of results Don’t assume all numerical differences

due to REAL hybrid differences… Minor differences may be due to

RANDOM errors How do we decide if difference is minor

or meaningful? Statistical models give LSD LSD = least significant difference

What’s an LSD (0.10)? Numerical differences smaller than

LSD are: Minor (“not significant”)

Can’t be 90% confident they are not due to random errors

Numerical differences same or larger than LSD are: Meaningful (“significant”)

Can be 90% confident they are not due to random errors

Example

Table 5 Maximum Yield at 35% DM is 24.79

ton/ac LSD is 5.25 24.79 – 5.25 = 19.54 So: If value is >=19.54, not

different from the top performer

QUESTIONS?

Average Relative Yield vs. Quality for all Test Sites in 2007

75

80

85

90

95

100

105

110

115

120

125

75 80 85 90 95 100 105 110 115 120 125

Relative Quality (lbs milk / ton DM)

Re

lativ

e Y

ield

(to

n /

ac

@ 3

5%

DM

)

A Picture Is Worth 1000 Tables

Higher YieldLower Quality

Lower YieldLower Quality

Lower YieldHigher Quality

Higher YieldHigher Quality

High Yielding and High Quality Hybrids In At Least 3 Site/Year Combinations in 2007

99

101

103

105

107

109

111

113

115

99 101 103 105 107 109 111 113 115

Relative Quality (lbs milk / ton DM)

Re

lati

ve

Yie

ld (

ton

/ a

c @

35

% D

M)

12

3

4

5

6

7

8

9

10

11

1213

Point ID Brand Hybrid1 DEKALB DKC64-78(RR2/YGCB)2 Doebler's 785RB3 Augusta A-06-10HX4 Southern States SS 783 RR2YGCB5 Southern States SS 647 VT36 DEKALB DKC64-23(RR2/YGRW)7 DEKALB DKC61-73(RR2/YGCB)8 Southern States SS 746 RR2YGCB9 Augusta A5175CB10 Mid-Atlantic MA8088VT311 DEKALB DKC66-23(RR2/YGCB)12 Augusta A-04-102CB13 Augusta A-04-94CB

A Picture Is Worth 1000 Tables

QUESTIONS?

CornPicker Software Tool

Partial budget approach to fine-tuning hybrid selections

Developed at Michigan State University

Excel software program available at: http://www.msu.edu/user/mdr/cornpicker.html (see handout)

Let’s take a look…

Corn Grain Test

Publication laid out the same Tables 1, 2 and 3 are the relative yields

Use these for comparison Remaining tables contain data for each

site Shenandoah Valley test: Tables 19 to 21

Tables are split by relative maturity Statistical methods are the same

Thanks

Any Questions?