2007 Sunflower Hybrid Performance Results
Tuesday, January 1, 2008
filed under: Hybrid Selection/Planting
Full results of public hybrid yield trial results for the 2007 season are available on the National Sunflower Associate website under the grower and production section: www.sunflowernsa.com/growers/yield.
Trials are presented by state. Most trial tables include additional data on production categories such as days to flower, days to maturity, plant height, test weight and disease ratings.
The following identify other sources of public sunflower hybrid performance information available online:
North Dakota State University Research and Research Extension Centers
South Dakota State University Crop Variety Trial Information
Colorado State University Sunflower Page
Kansas State University Crop Performance Tests
University of Nebraska Sunflower Testing
For a list of seed suppliers and seed company websites, go to the “Hybrid Seed Suppliers" page on the NSA web site.
Seed companies previewed new 2008 hybrids in The Sunflower’s December 2007 issue. That article ("Hybrid Selection/Planting”) can be seen online.
Making Sense of Statistics
• Expected mean in plot trial information refers to the average performance number for a particular trait of all hybrids evaluated in the trial. For example, if a performance trial table indicates one hybrid yielded 2,600 lbs/acre, compared to another hybrid in the same plot that yielded 2,310 lbs/acre — and the LSD for this plot trial data is 407 lbs/acre — there is no statistical difference in yield between the two varieties.
• Coefficient of variability (CV %), which is often listed at the bottom of a hybrid data table, is a relative measure of the amount of variation or consistency recorded for a research trial or particular trait within a trial, expressed as a percentage of the mean. Generally, trials with low CV rates are more reliable for making hybrid choices than trials with higher CV rates. Trials with CV rates below 15-20% are generally considered to be reliable for comparing yield. The National Sunflower Association does not publish trial results with any CV value over 20.
• To accurately determine whether one hybrid is better than another for a given trait, use the least significant difference value (LSD 5%) at the bottom of the table. This is a statistical way to indicate if a trait such as yield differs when comparing two hybrids. If two hybrids differ by more than the indicated LSD 5% value for a given trait, they would most likely differ again when grown under similar conditions. If two hybrids differ by less than the LSD, there’s no statistical difference.
In another example, if the oil content percentage for one hybrid is 44 compared to 41 for another, and the LSD is 2.3, the first hybrid can be expected to have higher oil content than the second hybrid, under similar growing conditions.
Give more weight to information from trials or fields close to your own growing area. It’s best to compare relative performance over multiple years and locations. Consult an agronomist or your local seed dealer for more-specific information.