When planting grass for pastures or hayfields, many farmers decide on the species and then pay little attention to the variety, buying whatever seed is cheapest or available. This is a little like deciding to add a cow to the herd but not caring whether it’s a Holstein or an Angus. Failing to select a high-performing grass variety can be a very expensive mistake.
Public grass-variety tests offer farmers valuable information, because different varieties are tested side by side and performance is determined to reduce the possibility that an unadapted and/or low-yielding variety will be chosen. Such testing is particularly important for cool-season grasses, since many varieties are developed in other countries and may not be best adapted to a grower’s region.
When selecting a grass variety, growers should consider yield, winterhardiness, maturity, yield throughout the season and disease resistance.
Yield is the most important consideration for any forage. In our grass trials, yield has ranged as high as 4 tons/acre dry matter between the top- and bottom-yielding varieties. An additional yield of 3-4 tons/acre for possibly an extra $2-5/acre seed cost seems like a good buy! Even in 2012, with the drought, one orchardgrass yielded 20% more than the lowest-yielding variety in our Wisconsin trials.
Winterhardiness among orchardgrass and tall fescue varieties varies greatly. Since many varieties are developed in countries with milder climates, it’s important to test their ability to withstand local winters.
The photo below shows an orchardgrass variety trial of a few years ago. Each rectangular plot holds a different variety. The brown rectangle on the lower left died over winter. The middle one survived the winter well for good summer yield. On the lower right, the brown rectangle with some green growth didn’t die, but suffered winter injury so badly that it greened up slowly, producing little first-cutting growth and low yields for the season.
Good winterhardiness in grass varieties increases winter survival and ability to produce good yield the following summer.
We generally want to select medium- to late-maturing varieties because they head out closer to when legumes head. This is especially important if mixing the grass in a hayfield. Some orchardgrass varieties head two to three weeks later than others. Late-maturing varieties head close to when clover or alfalfa would be harvested while early heading types mature and lose forage quality before the legume is ready to cut.
The cheapest seed tends to be the earliest maturing. A few cents more per pound of seed can make a big difference in maturation of the grass relative to the legume.
Some tall fescue and orchardgrass varieties yield more consistently throughout the season than others. Later-season yield of cool-season grass varieties is important to provide more pasture in late summer and fall and, in hayfields, to provide a more constant mix of grass and legume.
In hayfields, the common grass types produce 50-60% of growth in first cutting, with little grass in later hay or haylage harvests. Data on late-cutting yields compared to first-cutting yields show significant differences in season-long distribution of yield.
We at Wisconsin plot the yields of each cutting and then draw a line through them. If all cuttings yield the same, the line is flat (slope of 0), but if first cutting is predominant, then the line will have a negative slope. Smooth bromegrass will often have a slope of -10 or -12 with 60% or 70% of yield in first cutting. The orchardgrasses we have tested ranged from -1 (good) to -7 (high percentage of yield in first cutting).
Lastly, select orchardgrasses, meadow fescues, and tall fescues for rust resistance. Rust, a common disease in the Midwest, produces the orange fungal spores that can rub off on your shoes and pants. The disease reduces grass growth and yield, but more importantly makes the grass less palatable to cattle, sheep and other animals.
For data on grass varieties from trials at the University of Wisconsin, go to www.uwex.edu/ces/forage. Select “Forage Variety Trials Results” and make a choice under “Compare Cool-Season Grasses.” Selecting a good grass variety can mean a great difference in yield and a producer’s satisfaction with the grass.