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Warm Season Grasses
Several varieties of warm season grasses are presently under evaluation for performance in various locations around the state. ‘Cave-in-rock’ switchgrass is presently the highest yielding commercially available switchgrass adapted in New York. ‘Carthage’ is another variety with high biomass potential. If used for forage, ‘Shawnee’, a selection out of Cave-in-rock, for higher in vitro digestibility would be the best choice for this region of the country. ‘Sunburst’ is also a cultivar that is more adapted to colder areas, as it was developed in South Dakota. Big bluestem commercial varieties adapted to this region include ‘Niagara’, ‘Roundtree’, ‘Pawnee’, ‘Bonanza’, ‘Kaw’ and ‘Goldmine’. Kaw and Goldmine are later in maturity. Other warm season grasses currently being evaluated in Cornell’s trials are eastern gamagrass ‘Pete’ and the indiangrass varieties ‘Rumsey’, ‘Holt’ and ‘NE-54', with the latter being more adapted to northern locations. New varieties that are in development and in seed increases are underway by Universities, USDA and private companies. Big bluestem varieties Goldmine and Niagara did not establish as well as the majority of switchgrass cultivars in our 2007 seedings but may do well in the second year (2008) of our research trials.
Purchasing Seed. Warm season perennial grass seed is available from many commercial seed companies. Seed for our research trials was purchased from Ernst Conservation Seeds, Inc. located in Meadville, PA (Ernst Conservation Seeds has a very thorough planting guide for the Northeast USA and Canada see additional information); Stock Seed Farms in Murdock, NE; and the Gamagrass Seed Company in Fall City, NE.
It is important to ask for the highest quality seed available. A high quality seed lot will have a high percent germination rate, a high pure live seed (PLS) percentage, and a low dormancy rating. We will be conducting trials on seeding rates in the future. A successful stand of warm season grasses will have approximately 10-20 plants per square yard. As part of our research effort on establishing warm season perennial grasses we are collaborating with a seed scientist at Cornell (Dr. Alan Taylor, Geneva Campus) on seed germination and dormancy issues and will have more information on seed quality as the project continues.
Site preparation and establishment. Warm season grasses in the Northeast climate do not compete well with cool season grasses and weeds. Site selection and preparation are important for successful establishment. If possible, warm season grasses should be seeded in fields with low weed pressure. Roundup (glyphosate) should be applied in the fall prior to plowing and seeding. In the spring we recommend a second application of Roundup if weeds are a concern. The fields should then be plowed and cultipacked before seeding. Warm season grasses should be seeded around one week before the first date used for planting corn in your region with a cutoff of June 15th.
Some warm season grasses require special planting equipment due to the seed morphology. The fluffy big bluestem and indiangrass seed cannot flow through a typical seeder. For our large on farm strip research trials we used a Truax Drill seeder (owned by the USDA/NRCS Plant Materials Center at Big Flats, NY). Recommended rates/acre for warm season perennial grasses are generally lower than those used in our trials; however, our concern was to achieve a stand with which we could evaluate yield and biochemical qualities associated with conversion to combustible and liquid fuels. The seeding rate and depth used for our trials is shown in Table 1.
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Table 1. Plant variety, seeding depth and rate used for NYFVI trials |
|
Variety |
Seeding depth inches |
Seeding rate lbs (PLS)/acre |
|
big bluestem |
1/4 - 1/2 |
10-12 |
|
indiangrass |
1/4 – 1/2 |
with switchgrass 2-4 |
|
switchgrass |
1/8 – 1/4 |
10-12 |
|
eastern gamagrass |
1 - 1 1/2 |
8-10 |