Clarence Renk              Manager, Western Branch, OARDC
Joe Davlin                    Assistant Manager, Western Branch, OARDC
Eugene Balthaser          Manager, Jackson Branch, OARDC
Lynn Ault                     Manager, Schaffter Farm, Wooster, OARDC
Matt Davis                   Manager, Northwestern Branch, OARDC

Summary

This report is a summary of performance data collected from forage variety trials in Ohio. The 2007 report includes performance data of commercial alfalfa varieties in tests planted in 2005, 2006 and 2007 at four sites (Tables 2 to 7); evaluation of potato leafhopper resistance in alfalfa at South Charleston (Tables 8); red clover variety trial at South Charleston (Table 9); and grass variety trials at South Charleston (Tables 10 to 14). For more details on forage species and management, see the Ohio Agronomy Guide, Ohio State University Extension Bulletin 472, (available online at http://ohioline.osu.edu/b472/0008.html).

Interpreting Yield Data in this Report

Yield data are reported in Tables 2 through 14. Details of establishment and management of each test are listed in footnotes below the tables. Least significant differences (LSD) are listed at the bottom of Tables 3 through 14. Differences between varieties are significant only if they are equal to or greater than the LSD value. If a given variety out yields another variety by as much or more than the LSD value, then we are 95% sure that the yield difference is real, with only a 5% probability that the difference is due to chance alone. For example, if variety X is 0.50 ton/acre higher in yield than variety Y, then this difference is statistically significant if the LSD is 0.50 or less. If the LSD is 0.51 or greater, then we are less confident that variety X really is higher yielding than variety Y under the conditions of the test.

The CV value or coefficient of variation, listed at the bottom of each table is used as a measure of the precision of the experiment. Lower CV values will generally relate to lower experimental error in the trial. Uncontrollable or unmeasurable variations in soil fertility, soil drainage, and other environmental factors contribute to greater experimental error and higher CV values.

Results reported here should be representative of what might occur throughout the state but would be most applicable under environmental and management conditions similar to those of the tests. The relative yields of all forage legume varieties are affected by crop management and by environmental factors including soil type, winter conditions, soil moisture conditions, diseases, and insects.

Alfalfa

Alfalfa has the highest combined yield and quality potential of any adapted perennial forage grown in Ohio. It is the state's largest single hay crop, being grown on about one-half of the total hay acres. Alfalfa requires well-drained soils with near-neutral pH (6.5-7.0) for greatest production and persistence. Alfalfa trials are initiated each year and data is collected for at least four years unless the stand becomes so depleted that further testing is no longer worthwhile; variety performance should be evaluated over several sites and years.

Guidelines for Selecting Alfalfa Varieties

To capitalize on alfalfa's potential, select high-yielding varieties with resistance to problem diseases. Consider these factors when selecting alfalfa varieties for Ohio:

1. Yield. Yield is the major factor in determining profitability of an alfalfa stand. Select varieties with high yields over several locations and years. Table 3 shows this comparison in percent of the average yield. Varieties that perform equally well across several locations and years are probably adapted to a wider range of environmental conditions. Stable yield performance across several environments is important because soils may vary on your farm and weather conditions vary from year to year. Conditions on most farms are such that several varieties may perform equally well.

2. Persistence. Another important consideration beyond yield is how long the stand will last. Study variety performance by age of stand to get an estimate of longevity of stand productivity. Some varieties may decline with age more rapidly than others. This may influence your choice of variety depending on how long you intend to keep the stand in production. For long-term rotations, choose varieties with good disease resistance and good performance in the fourth year of production. If you plan to harvest alfalfa for three years or less, then high performance during early years of the stand should be given major consideration.

3. Fall dormancy (FD). Alfalfa varieties with fall dormancy ratings of 1 through 5 are considered adequately winter hardy for Ohio conditions while those of 6 or higher are not considered adapted. Varieties with higher fall dormancy ratings tend to grow at a lower temperature. Thus they begin to grow earlier in the spring and later into the fall, extending the growing season. The fall dormancy rating does not correlate well with winter hardiness within the range of varieties adapted to the Midwestern USA.

4. Disease resistance. Variety selection based on yield performance alone is less satisfactory than selections that also consider disease resistance characteristics. Resistance to specific disease-causing pathogens may be the most important attribute in an alfalfa variety. Pathogens can dramatically reduce yield and persistence of susceptible varieties. In a recent evaluation of older versus newer alfalfa varieties we found that varieties released in the mid-1990’s yielded more (0.25 ton per acre more each year) and persisted longer than older varieties, primarily because of improved resistance to diseases that affected the trial. For more information on alfalfa diseases and varietal resistance to specific diseases, go to the following websites:

http://www.uwex.edu/ces/forage/pubs/varinfo.htm

5. Insect resistance. Alfalfa varieties have been developed for resistance to potato leafhopper (PLH), which is the most consistently damaging insect pest of alfalfa in Ohio. This report includes several trials where yield tolerance to PLH damage is being evaluated. Please note that the PLH resistant varieties are not resistant to the alfalfa weevil, and they will need to be protected from that pest like all standard alfalfa varieties when weevil populations exceed the economic action threshold. For more information on insect management in alfalfa, see the following website: http://agcrops.osu.edu/insects/

6. Compare to check variety. For comparisons of varieties across several trials, always compare varieties to the same check planted within the trial. The variety Vernal is used as a check in all Ohio trials.

7. Use good management. No variety can produce well under poor management. Good management considers all aspects of alfalfa production: seed bed preparation, liming and fertilization, seeding, pest control, harvest, storage, and post harvest treatment. Many newer varieties are better adapted to intensive management.

The growing season began with above normal temperatures in March followed by below normal temperatures in April, including several days when temperatures fell below 20 F, killing back early spring growth. Forages in the southern two-thirds of the state were most severely affected by the late spring freeze. Temperatures were above normal all months except April and July. Several months had below normal rainfall at all locations. Total rainfall for the season was above normal at N. Baltimore (+2.4 inches) and Wooster (+1.6 inches), but below normal for South Charleston (-2.0 inches) and Jackson (-9.0 inches). Yields were below the record highs of 2006.

Alfalfa

The trial established in 2006 at Wooster had the highest yields, averaging 7.4 tons/acre. Alfalfa weevil populations were low at all sites and no insecticide was required for their control. Insecticide applications were used at all locations for control of potato leafhopper (PLH) in the standard yield trials.

No insecticide was applied to control potato leafhopper in the Regional Alfalfa Yield Trial for Potato Leafhopper Resistance conducted at South Charleston, OH and Ames, IA. Leafhopper populations were above economic thresholds at both locations, resulting in significant yield differences among varieties in response to PLH injury. Leafhopper resistant varieties are not resistant to alfalfa weevil, and will need to be treated with insecticides if weevil populations exceed action thresholds.

Red Clover

Forage yields of red clover varieties were 5 tons/acre or higher in 2007, except for Red Gold (due to poor establishment) and common seed (due to stand loss from diseases). Newer varieties of red clover yield more and persist longer than common red clover.

Orchardgrass

Yield in 2007 was lower due to the reduced rainfall. Orchardgrass varieties differed greatly in yield over the season, and all varieties went dormant for part of the summer due to drought.

Tall Fescue

The tall fescue trial of endophyte-free varieties established at Jackson in 2004 had lower yields in 2007 than in 2006. New varieties that are endophyte free or that contain a non-toxic endophyte (eg., Jessup Max Q) have potential to increase animal performance during the summer grazing season and to provide forage for beef cattle and sheep during autumn and early winter.

Perennial Ryegrass

The perennial ryegrass trial at South Charleston also had lower yields in 2007. Only two harvests were made due to the reduced growth from below normal rainfall. Perennial ryegrass (diploid and tetraploid) is the most winter hardy of the ryegrass types. A couple of varieties in the ryegrass trial were festuloliums, which are crosses between annual ryegrass and fescue. They generally are more winter-hardy and slightly more drought tolerant than perennial ryegrass.

Annual Ryegrass

Total forage yields in the annual ryegrass trial seeded September 2006 ranged from 0.33 to 3.6 tons/acre among varieties, partially due to large differences in winter injury (note % stand density in April). A new trial was seeded September 2007, and one harvest was taken in early November. Winter survival and yield will be evaluated in that trial in 2008. Annual ryegrass is a cool-season annual bunch grass that is highly palatable and digestible. It has high seedling vigor and is well adapted to either conventional or no-till establishment methods.

Inclusion of entries in Ohio Alfalfa Performance Trials does not constitute an endorsement of a particular entry by The Ohio State University, Ohio Agricultural Research and Development Center, or Ohio State University Extension. Where trade names appear, no discrimination is intended, and no endorsement is implied by The Ohio State University, Ohio Agricultural Research and Development Center, or Ohio State University Extension.

Go to Ohio Crop Performance

12/2006
All educational programs conducted by Ohio State University Extension are available to clientele on a non-discriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status.

Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, Keith L. Smith, Director, Ohio State University Extension.

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