Commodities: Field Crops: Forages
Forage Variety Trial Information
Robert Morgan, John Andrae, Greg Durham, and Dennis Hancock
Introduction
As producers make the decision on which forage species and variety to establish, it is helpful to compare available varieties. The variety trials detailed on this site provide yield results for several (but not all) varieties that are available for some of the forage perennial grass species that grow well in Georgia. Because of the diversity of soil and environmental conditions in Georgia, variety trials are performed at multiple sites. To best understand the productivity of these species/varieties, examine the data from the location that is most representative of the area where the forage will be established. For a better understanding of the yield results, weather data are presented below from each location for which yield data are presented.
Weather Data Summary
Location Year Blairsville Calhoun Athens Griffin Tifton
Plot Establishment and Management
All variety trials were established in accordance with UGA recommendations specific to the evaluated species. Plots were limed and fertilized according to recommendations from the Soil Test Handbook for Georgia. Harvest timing and pest management practices for these trials were also in accordance with standard University of Georgia recommendations. Plots were arranged in a completely randomized design with each individual entry replicated four times in each trial. The results were analyzed using PROC GLM in SAS 9.0. Entry means were separated using a Least Significant Difference (LSD) procedure (P<0.05).
Interpreting the Variety Trial Results
The results are presented in the following sections, which have been arranged by the species evaluated and location. To review the results at each harvest period during the trial's duration, click on the years indicated. This will open a printable form (pdf) of a table that summaries the yield data from each harvest in that trial. Yield means followed by different letters (e.g., values like "2100 a" and "1200 b") are significantly (P<0.05) different. Yield means that are followed by the same letter (e.g., values like 2100 a, 2074 a, or 1950 ab) are not significantly (P<0.05) different.
A "Summary" graph is also provided for each trial. The graphs present the average total yield for the growing season for each entry. The graphs employ the same lettering technique that was used in the tables to aid mean separation.
Bahiagrass
Griffin
Tifton
Bermudagrass, Hybrid
Calhoun Griffin
Tifton
Bermudagrass, Seeded
Calhoun Griffin
Tifton
Tall Fescue
Blairsville Athens
The Limitations of Forage Variety Trial Data
It is critically important for one to understand what variety trial information will and will not provide. Forage variety trials reported here are managed as if they were being harvested for hay production. Thus, the results of these trials generally show the differences in the productivity of the different forage species and the varieties evaluated. Great care is taken to ensure that all entries are managed equally and that the yield potential of each can be realized in the given location and environmental conditions for the given year or set of years.
However, such yield data alone may reveal very little about:
- The productivity of these species/varieties when grazed,
- How persistent the species/varieties are under haying or grazing,or
- How these species/varieties will perform when soil conditions and management are less than ideal.
Nonetheless, forage variety trial data generally identifies differences between species and among their varieties. Most research has shown that varieties that stand out (either positively or negatively) in variety trials will show similar traits when grazed and/or subjected to poorer conditions. Therefore, variety trial data provide comparisons that generally relate well to performance on the farms represented by the location of the test.