Using UNL Variety Trial Data to Select Hybrids
January 23, 2009
Hot off the Press: UNL's Spring 2009 Seed Guide
The producer's field is the most reliable environment for observing hybrid performance. That's why UNL's Variety Testing Program evaluates hybrids and varieties in on-farm trials where participating farmers manage the field practices and inputs.
UNL Variety Testing
Results of UNL variety trials are available at varietytest.unl.edu.
Data are available for corn, soybean, alfalfa, winter wheat, sorghum, oat, proso millet, sunflower, spring wheat, and barley from 2000 to 2008.
Results are also available for dry beans, oilseed crops (brassica, camelina and canola) and other crops (foxtail millet for grain or forage, pea for grain or forage, chickpea, amaranth) for fewer years.
To obtain a printed copy of the 2009 Spring Seed Guide, contact your local UNL Extension office, call the Publications Warehouse at 402-472-9713 or use the form at http://elkhorn.unl.edu/epublic/UserFiles/Image/puborderform.pdf Cost is $1 (plus shipping and handling for mail order).
Results reported by this program are the most unbiased and real world representation of major hybrids marketed in Nebraska and the surrounding states. The program treats all hybrids equally and reports the results annually in the UNL Seed Guides - one for fall planted crops and one for spring planted crops. These guides are important tools in helping you, the producer, make informed decisions on hybrid selection for next year.
Contents of Spring 2009 Seed Guide
The 2009 Spring Seed Guide contains data from corn entries evaluated at 20 locations — 7 rainfed and 13 irrigated, including one in Wyoming. Soybean entries for both early and late groups were evaluated at 17 locations — 6 rainfed and 11 irrigated. The seed guide also includes field results for grain sorghum, alfalfa, sunflower, and proso millet. Variety trial results also are available online at http://varietytest.unl.edu/corn/2008.html.
How Crop Trials are Conducted
All tests are conducted in fields that farmers plant to the same crop. Experimental plots are surrounded by the farmer's crop and receive the same management. Farmer entries are included as local checks. Results are combined across sites for sites that have the same growing conditions and across seasons when the hybrid is entered for more than one season.
Least significant differences (LSDs) are shown at the 10% level of probability. This means that when the difference between two hybrids within a test is equal to or greater than the LSD value, you can expect that nine out of ten times the average yield between the two hybrids will be different. When the difference is less than the LSD value, ther difference may still be real, but there was no evidence that it was repeatable.
Using the Seed Guide to Select Seed
Here are some specific suggestions on how to use the information in the seed guide to select top performing hybrids for next year.
Look first at hybrids that performed well at trials held nearest to your farm or at locations with similar growing conditions, including rainfall distribution and temperature patterns (cumulative degree days).
Give more weight to hybrid performance data from several years or from several sites. This information provides a better measure of yield stability than information from a single year or site. Every season comes with surprises. A hybrid that has stable performance across years and a range of conditions is likely to out perform one tested under limited, specific conditions. Look at hybrids with results from multiple sites even if the sites are different from yours.
Use check entries as a yard stick for comparing results. The producer selected the check hybrid/variety based on prior knowledge relevant to that location.
Beware of data from unusual seasons. Last season was uncommon in terms of rainfall during planting and harvest, which may have confounded the performance of some hybrids over another. Since all hybrids do not respond similarly to changes in conditions, it's fair to assume that some would perform differently during a more normal growing season.
Set a realistic yield goal, one that can be achieved with a reasonable chance of success. It should reflect your resources and your field's capacity to produce it with a level of economically sensible inputs. Depending on your farm condition and management style, you may consider potential benefit form stalks and crop aftermath.
- Look for other agronomic characteristics such as plant height, ease of combining, ease of shelling, less lodging, low shattering, low rate of ear drop, dry down rate, and others as applicable.
The seed guide provides valuable information about Nebraska-grown hybrids, allowing you to select ones that are most apt to perform well under your field conditions.