2007 Virginia Tech Corn Silage Hybrid Evaluation Program Brian Jones Agronomy 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 S-.127B-.25Zn Plot size: 2 30” rows x 25’ with 4 replications Seeding rate: 25,000

Shenandoah Valley Test Details Harvested 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 * = 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 ton/ac LSD is – 5.25 = So: If value is >=19.54, not different from the top performer

QUESTIONS?

A Picture Is Worth 1000 Tables Higher Yield Lower Quality Lower Yield Lower Quality Lower Yield Higher Quality Higher Yield Higher Quality

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: (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?