Frequently Asked Questions
General
OVT PROGRAM'S PURPOSE
Short answer: Get high-quality data to the stakeholders (growers, extension, industry) so they can make informed decisions regarding variety selection. The goal is to empower the stakeholders with unbiased data.
CROPS/SPECIES EVALUATED
- Corn
- Cotton
- Grain Sorghum
- Peanut
- Soybean
- Winter Grains/Small Grains
- Barley
- Wheat
- Oat
- Triticale
- Winter Forages
- Wheat
- Oat
- Rye
- Ryegrass
- Triticale
REDUCING RISK
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One of the easiest ways to spread risk is diversification. Don’t put all of your eggs in one basket.
In the world of agriculture, there are numerous ways to implement diversification into a risk management plan.
- plant different crops/species
- plant more than one variety
- planting date
REGIONS & LOCATIONS
![AAES-variety-form-turn-in-locations](https://aaes.auburn.edu/wp-content/uploads/sites/2/sites/2/2023/01/AAES-variety-form-turn-in-locations.jpg)
- Tennessee Valley Research and Extension Center (TVREC) – Belle Mina
- Sand Mountain Research and Extension Center (SMREC) – Crossville
Central Region
- Chilton Research and Extension Center (CREC) – Clanton
- Prattville Agricultural Research Unit (PARU) – Prattville
- Black Belt Research and Extension Center (BBREC) – Marion Junction
- EV Smith Research Center (EVSRC) – Tallassee/Shorter
South
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- Wiregrass Research and Extension Center (WREC) – Headland
- Brewton Agricultural Research Unit (BARU) – Brewton
- Gulf Coast Research and Extension Center (GCREC) – Fairhope
INVOICING & BILLING
Invoices for trial participation are typically sent once all seed has been received, and the entry list has been finalized.
Please make checks payable to Auburn University Crop, Soil, & Environmental Sciences.
Credit card payments can be made upon request.
OUT OF STATE COLLABORATORS - 3RD PARTY DATA
Because multiple states use Medius Ag as their variety trial database solution, datasets from these collaborators can be dynamically merged on demand and viewed simultaneously.
To make this happen, users must click the “include 3rd party data” button when viewing data. They will then have the option to include data from other collaborators.
In addition to the complete set of Alabama variety trials, stakeholders currently have the ability to include results from the following partners.
University of Florida
- Peanuts (multiple locations)
- WFREC – Jay
- Cotton
- Corn
- Soybean
University of Georgia
- Peanuts
NC State University
- Corn
- Wheat
- Soybean
Clemson University
- Corn
- Wheat
- Soybean
- Cotton
OVT SMALL PLOTS VS ON-FARM
Both OVT small plots and on-farm results are available in the online variety selection tool. Both are valuable and should be used in tandem. Strong caution is advised if making a decision on on-farm data alone.
OVT Small Plots | On-Farm | |
Conducted by: | OVT Program | Extension |
Located | AAES Research Stations | Grower Fields and Research Stations |
Plot Size | Small | Large |
# of Varieties | More (up to 50+) | Fewer (less than 15) |
Types | Released & Experimental | Mostly Released |
Replication | Always | Peanuts yes, others minimal |
Statistical Analysis | Always | Peanuts yes, others none |
Equipment | Research | Commercial |
SHORTCUTS
When data is posted to the Auburn University Variety Testing webpage, links are provided to view the data in the online tool.
There are posts with links to trials, weather & trial management, location summaries, and statewide/regional summaries available on the Auburn University Variety Testing website.
PDF REPORT
Look for the “View Report in PDF” button at the bottom of each OVT webpage/post.
To view multi-location & multi-year data, look for links to summary tables and use the online variety selection tool, or print out the PDF reports and get your calculator ready.
ONLINE VARIETY SELECTION TOOL
Stakeholders can customize how they look at their variety trial data and have more confidence that they are making informed decisions.
The Auburn University Variety Testing Program uses Medius Ag as a variety trial database solution.
Funding for the online variety selection tool comes from multiple sources:
- Auburn University
- Alabama Cooperative Extension
- Alabama Commodity Groups
- Cattlemen’s Association
- Cotton Commission
- Peanut Producers
- Soybean Producer’s
- Wheat and Feed Grains
OTHER OVT PROGRAMS
Statistics
VARIATION, REPLICATIONS, & RANDOMIZATION
It would be nice for a field to be 100% uniform, but that is not what happens in the real world or research. In order to account for naturally occurring variation, the variety trials are replicated.
This means that each variety is planted multiple times within a trial. The average of those plots is the value that gets reported.
Each plot of a variety is randomly distributed within a trial. The typical experimental design is a randomized complete block.
LEAST SIGNIFICANT DIFFERENCE (LSD)
Least significant difference (LSD) is used to determine whether the observed differences are real or are caused by random variation.
When using the LSD, two entries may have numerically different values, but the values are not statistically different.
When two entries are compared, and the observed difference is larger than the LSD, the entries are considered statistically different.
An alpha level of 0.10 is used, meaning that the differences observed are expected to be real 90% of the time.
TOP GROUP
For individual trials, varieties are split into two groups. The first group is statistically NOT different from the best value. This group is given a value of 100% in the top group. The second group is statistically different from the best value and is not in the top group, 0%.
For multi-year or location data, these values get averaged and show the percentage of time that the variety was in the top group. This helps show consistency across locations and time.
Z SCORE
The z-score gives the distance from the trial mean measured by the standard deviation.
A positive number is above the trial mean. A negative number is below the trial mean.
The online variety selection tool uses the z-score to allow users to rank a list of varieties based on multiple data fields. This is under “Total Scores”.
% MEAN
=value/trial mean
Is a value 90, 100, or 120% of the trial mean?
This is often used on on-farm trials with no statistics.
Crop Specific Considerations
COTTON
Planting Date: Planting date can make a massive difference in variety selection. Results are broken into two categories based on planting date. Both categories are planted and managed independently.
- Full Season – First Week of May
- Short Season – Last Week of May – First Week of June
Irrigation: Some varieties perform better in either irrigated or non-irrigated conditions. Most cotton locations have both irrigated and non-irrigated versions of the full and short-season trials.
Loan Value: This documents how quality can impact value. This is a way to look at all 4 quality measurements combined.
In the online variety selection tool, quality results are given values based on the USDA premiums and discounts for uniformity, strength, length (staple), and micronaire. These premiums and discounts are then applied to a base rate of $0.52 per pound. The resulting loan value is provided in dollars per pound.
Value per Acre = Loan Value x Yield
When loan value is multiplied by the yield, the result is the value per acre ($/acre).
When making a variety selection, do not base your decision on value per acre alone.
PEANUTS
Disease Ratings: Dr. Amanda Scherrer’s Plant Pathology program rates all of the peanut OVTs for Tomato Spotted Wilt Virus, White Mold, and Leaf Spot. Varietal differences in susceptibility should play a major role in variety selection.
Loan Value: This documents how quality can impact value.
The online variety selection tool gives quality results values based on the USDA premiums and discounts for Total Sound Mature Kernels, Other Kernels, Damaged Kernels, & Loose Shelled Kernels. The resulting loan value is provided in dollars per ton.
Value per Acre = Loan Value x Yield
When loan value is multiplied by the yield, the result is the value per acre ($/acre).
When making a variety selection, do not base your decision on value per acre alone.
SOYBEAN
Maturity Group: Soybean varieties are broken out into their respective maturity groups when they are evaluated. The typical breakdown is MG4, MG5, MG6, MG7-8.
In the North Region, maturity groups 4 & 5 soybeans are evaluated. In the Central and South Regions, maturity groups 4-8 are evaluated.
Iron Deficiency Chlorosis (IDC): Soybeans grown in some of the Black Belt region’s high pH soils can develop iron deficiency chlorosis. Each season, the Auburn OVT program conducts a trial at the Black Belt Research & Extension Center (BBREC) in Marion Junction to evaluate varietal tolerance to IDC. Yields (when harvestable) and ratings are reported on a scale of 1 to 9. A rating of 1 would be no damage. A rating of 9 would be a total failure.
WINTER FORAGES
Species Selection: There are some major differences between the five winter forage species that Auburn Variety Testing evaluates: production timing, forage quality, yield, maturity, etc.
Production Timing: When do you need the forage? Some species/varieties can provide much more early-season (before mid-March) grazing than others. Some perform best later in the season. Some can hang on and keep producing through June.
Maturity: When will the plants swap from vegetative to reproductive growth? This is an important factor to consider if you are worried about how the temporary winter forage will impact the overseeded permanent warm-season pasture.
Hayleage: The experts say don’t cut more than you can handle. Think about using species/varieties that will be ready at different times throughout the season. This could break harvests up into more manageable scenarios.
Ryegrass: Many retailers only offer/stock a handful of varieties. For the 2023 & 2024 seasons, the Auburn OVT program evaluated approximately 50 varieties yearly. If you find a variety that interests you and your retailer doesn’t have it, that doesn’t mean that it isn’t available. Check with the company (seed source) listed in the dataset; they can help you find their variety.
Quality and Yield: Because TDN & CP are percentages, pounds of TDN and pounds of CP per acre can be calculated. These values demonstrate how yield and quality interact. When quality is taken into consideration, the ranking of varieties can change.
Latitude: As you move North in the state, it will take longer to get to the first measurable grazing event. Looking at the OVT results, for every 9 miles traveled North, it adds approximately 2 additional days to reach that first grazing event. For example, the first ryegrass harvest at Fairhope typically happens around 80-90 days. The first harvest in Crossville is often between 130-140 days.
Subscribe to AU Variety Testing Updates
Annually, the Auburn University Variety Testing Program conducts trials on corn, cotton, soybeans, peanuts, grain sorghum, wheat, barley, oats, triticale, small grain forages, and ryegrass.
Trials are conducted on Auburn University owned and operated agricultural research stations across the major geographical regions of the state. The research conducted at each of these locations can provide stakeholders with data that can be more representative of their growing conditions.