Intraspecific variation and thermotolerance classification 5using in vitro seed germination assay tial and model lignocellulosic biofuel feedstock by the u. Herbicides labeled for use on switchgrass on crp land can also be legally applied. This warmseason grass is an exceptional forage for pasture and hay for livestock. Quiescence is the nongermination of viable and nondormant seeds, due to absence of favourable environmental conditions, e. Switchgrass should be seeded in a pure stand when used for pasture or hay because it can be managed better alone than in a mixture. Switchgrass panicum virgatum switchgrass is a warmseason perennial that typically grows to 37 feet high. Treating seed to break dormancy, and seed storage in perennial grass seed, dormancy is part of a plant reproductive strategy that limits seed germination until conditions are optimum for seedling survival. Switchgrass has 380,000 to 400,000 seeds per pound which is more seed per acre than the other native. Switchgrass is slow to establish, often requiring two to three growing seasons to become fully established as a dense and vigorous stand.
Since native grasses, like switchgrass, are sold on a pls pure live seed basis, one will always know the viability of the seeds. When planting for wildlife, reduce the seeding rate by 5060% e. Approaches to manage seed with high dormancy include storing the seed for at least a year. For the cultivation of switchgrass, however, it may be desirable to break dormancy to allow for. Given the large increase in genomic and other resources for switchgrass. All seed was provided by a single commercial grower ernst con. Whitten plant materials center coffeeville, ms seed. Planting and managing switchgrass for forage, wildlife, and. A potential for two nosensors in switchgrass seeds. Department of energys bioenergy feedstock development program 7. It is adapted to sandy soils of texas, and the wet, acid soils of east texas. Investigating seed dormancy in switchgrass panicum virgatum. In the southeast, a planting rate of approximately 10 pounds pls per acre is recommended.
Switchgrass shelter seeds panicum virgatum american meadows. Sow seed at a rate of approximately 46 pounds of pure live seed pls per acre drilled in a pure stand. Dormant seeding is planting switchgrass seed in late november or december. Switchgrass can also have a high percentage of naturally dormant seed. Switchgrass is easily identified by a small nest of hair where the blades attach to the sheath. Weed competition, seed dormancy, and poor seedling vigor are the most frequent limitations to rapid establishment. A chemical scavenger of no effectively blocked the enhancement of germination induced by no or ros suggesting that ros action is at least partially perceived through no. In ontario, big bluestem can be included in mixtures with switchgrass to enhance environmental benefits and to reduce potential for disease. Evaluation of switchgrass genotypes for coldtolerant seed. In 2008, a second seed lot with higher seed dormancy was planted to evaluate the difference in seed dormancy on dormant seedings.
A larger seed such as a fescue can be seeded at 10lbs1,000 square feet. Senescence, dormancy and tillering in perennial c4 grasses. Switchgrass provides excellent erosion control when used as filter strips, grass hedges, or. However, some degree of dormancy is advan tageous, at least during seed development. Delaying seed germination until the conditions for seedling survival are most favorable.
Seed older than two years may become less viable and have poor seedling vigor under. Investigating seed dormancy in switchgrass panicum. Growing and harvesting switchgrass for ethanol production in. Switchgrass is a vigorous, native, perennial, bunchgrass that grows throughout most of the united states. Broadcast seed at a rate of 810 pounds of pure live seed pls per acre for a pure stand. Seed dormancy is typically reduced if the seed is properly aged for one year. Seed dormancy and the control of germination william e. Aged switchgrass seed lots response to dormancybreaking chemicals gautam sarath and robert b. Seed dormancy is typically reduced if the seed is aged for one year at room temperature. Switchgrass produces large seeds on a spangledtype seed head. Tischler and others published techniques for reducing seed dormancy in switchgrass find, read and cite all the research you need on researchgate. Jul 10, 2007 freshly harvested seed can have a high percentage of dormancy. It is very important to adjust the seeding rate for pls for each new seed lot that is used, since pls varies from one seed lot to another.
Planting and managing switchgrass for forage, wildlife. It is highly adaptable to a wide range of soils and growing conditions. For newly harvested seed, a dormancy rating of 10 percent or less is excellent. This model assumes that no is an obligate part of aba action in plants. Although germination and purity percentages must be reported on switchgrass seed tags, the number of seeds per gram is not. Switchgrass seed varies in the degree of dormancy, causing some seed to germinate when growing conditions are favorable and some to remain dormant as a backup reserve. Switchgrass establishment noble research institute. There are a number of studies claiming significant energy returns using switchgrass as a solid fuel in the form of switchgrass pellets or as a feedstock for cellulosic ethanol. The availability of latitudinally adapted populations for switchgrass presents an opportunity to dissect molecular mechanisms that can impact senescence, dormancy and winter survival. Understanding the causes for this dormancy will provide better insight into seed physiology, and potentially lead to treatments that reduce variability in seed. Pdf investigating seed dormancy in switchgrass panicum. Seed treatments improve the germination and seeding emergence.
Switchgrass has a large genetic diversity because of the wide range of environments in which it grows and is classified as. Properly stored switchgrass seed will naturally decrease in dormancy. In this instance, a great way to break switchgrass seed dormancy is to frost seed, which exposes the seed to the natural freezethaw cycle that seed would have gone through by dropping to the ground the previous fall. Studies on the plasticity of dormancy and on aging in. Planting rates vary depending on the size of the seed. Dormantseason planting and seeddormancy impacts on. Studies on the plasticity of dormancy and on aging in switchgrass seeds. The combined results of this study demonstrated that switchgrass seed dormancy and germination were highly variable among different genetic backgrounds, similar to other grasses, including panicum coloratum l. Breaking seed dormancy may be accomplished by storing the seed at room temperature for 12 to 18 months after harvest. Aged switchgrass seed lots response to dormancy breaking chemicals gautam sarath and robert b. How to establish and maintain a switchgrass stand deer. One of the challenges of planting switchgrass and especially cir switchgrass is the high dormancy of the seed that must be accounted for. Managing weeds in switchgrass grown for biofuel rick boydston usdaars.
Data described above would favor the presence of at least two nosensors in seeds as shown in figure 1. Freshly harvested seed has a low germination rate and must be treated to break dormancy. Switchgrass is an earlymaturing warmseason grass late mayearly june. Request pdf breaking seed dormancy of switchgrass panicum virgatum l. Approaches to manage seed with high dormancy include storing the seed for at. Native warm season grass biomass ernst conservation seeds is one of the largest switchgrass seed producers in the country, with more than 30 years of experience in establishing, managing and harvesting native, warm season grass seed and biomass from these species. Seed older than two years may become less viable and have poor seedling vigor under field conditions.
During the winter, the seed experiences cold, moist. Cavenrock is known to provide excellent nesting, brood rearing, and winter cover for pheasants and other birds due to its upright growth and stiff stems. This dormancy needs to be broken before it will germinate. Cavenrock switchgrass is a perennial, warm season native grass that grows an average of 35 feet tall, but in some regions, can reach up to 6 feet tall at maturity. Seed dormancy is generally an undesirable characteristic in agricultural crops, where rapid germination and growth are required. Switchgrass, panicum virgatum, is the most productive and commonly talked about native, warm season grass being considered as a feedstock for alternative fuels and sustainable fiber. It will grow in loams and clay loam soils if the water relationship is good. Whitten plant materials center coffeeville, ms vol. This sufficient germination levels and could reduce seed viability. For example, seeds may be shed from the plant in late summer or early. Blade products will be labeled with recent seed test data to indicate the current level of dormancy for a.
For this reason, it is often best to order seeds one year before planting is to occur. There are a number of studies claiming significant energy returns using switchgrass as a solid fuel in the form of switchgrass pellets or as a feedstock for. Pdf techniques for reducing seed dormancy in switchgrass. Its slick, freeflowing seed can be planted with most seed drills or with a broadcast spreader. Since it is a tallgrowing grass, the management must differ from that used for coolseason grasses.
Switchgrass seed robert geneve, university of kentucky. Recently, switchgrass has attracted attention as a potential bioenergy crop. Germination and emergence tests for predicting switchgrass. Think of it this way, if youve ever owned an older dog that needed milk poured on his dogfood to soften it up for easier chewing, switchgrass seeds are similar as well. Evaluation of a seed vigor test and seed dormancy on. Newly harvested switchgrass seed can have a high percentage of dormancy. It is important to be aware that there can be wide variation among switchgrass seed lots between germi nating seed and dormant. Wsda has ruled that switchgrass is considered a forage, fodder, and hay crop, included in crop. This lengthy afterripening period can be reduced by cold stratifying the seed zarnstorff et al. Extreme temperatures are the single most important factor delimiting the distribution, adaptability, and yield potential of plants.
Dormant seeding of switchgrass with and without seed. Switchgrass establishment requires patience posted jul. Evaluation of a seed vigor test and seed dormancy on germination and emergence of switchgrass for biomass production prepared by sid bosworth, extension agronomist switchgrass panicum virgatum is considered one of the most viable perennial grass species for utilization as a biomass crop in the u. Native warm season grass biomass ernst conservation seeds. Switchgrass seed is very small and much of it will not germinate right after it is harvested. Seed dormancy is a significant issue to consider before planting switchgrass. Breaking seed dormancy of switchgrass is a first step to reduce risk of establishment failure and the. In contrast, the use of switchgrass in pastures and hayfields in georgia is limited because other introduced species e. Although switchgrass spreads by rhizomes and seed, loose clumps or patches are usually formed. Thus, dormancy is an adaptive trait that optimizes the distribution of germination over time in a population of seeds. Identification and description research and extension. Mitchell abstract aged switchgrass seed lots can display various levels of dormancy.
Seed exposed to cold, moist conditions in the soil also loses its dormancy conditions through a process called. Methods used to break dormancy are letting the seed age for 1 to 2 years after harvest, or seed stratification. The pericarptesta is the primary morphological structure restricting switchgrass germination, while the lemma and palea also contribute to seed dormancy but to a lesser degree. The stem is round, hollow, and usually has a reddish tint. Breaking seed dormancy of switchgrass is a first step to reduce risk of. Switchgrass seeding recommendations for the production of. Prechilling switchgrass seed on farm to break dormancy.
Switchgrass bamert seed buy online direct from our farm. In general, seed that is two to three years old will have lower levels of seed dormancy than new seed. The height and extensive root system of switchgrass can cause it to become dominant over time in mixtures with other natives. Switchgrass and other warmseason grasses requi re a soil temperature above 50 degrees f for satisfactory germination. Switchgrass switchgrass is a warm season, native bunch grass. There are ecological advantages for plants with seed dormancy. The plant also provides excellent cover for wildlife populations. Seed and bud dormancy also exist in several plant species leading to delay in germination. The seeding rate for switchgrass is 56 lbs of pure live seed pls per acre for forage and biomass crops. Breaking seed dormancy of switchgrass is a first step to reduce risk of establishment failure. It is most productive, however, when grown on moderately well to welldrained sites of medium fertility. The seed is smooth, freeflowing, and can be planted easily with most grass drills.
Switchgrass breaks winter dormancy in late april and can provide some grazing in late may, but makes the most of its growth in june, july, and august. The management and use of switchgrass in georgia uga. When establishing switchgrass, buying quality seed is an important consideration. Established switchgrass stands are very resilient to the environmental fluctuations.
Acceptable germination levels often are achieved after one year of storage. Pdf stratification in switchgrass seeds is reversed and. Tischler and young, 1987 and in other studies on switchgrass robocker et al. Evaluation of a seed vigor test and seed dormancy on germination and emergence of. Dormant seeding is planting switch grass seed in late november or december. It prefers lowland, moist sites, but is adapted to a wide range of soils and climates including sand.
Seed dormancy is a plant reproductive strategy that increases sur vivability in the wild. Switchgrass can be grown on marginal land and is adaptable to a variety of soil types. As with many perennial grasses, switchgrass seed is in a natural dormant state when initially harvested. However, aging, treating with water and chilling temperatures stratification or storing it in warm conditions will break dormancy. May 01, 2009 switchgrass breaks winter dormancy in late april and can provide some grazing in late may, but makes the most of its growth in june, july, and august. Seed ecology dormant seeds are unable to germinate even when the conditions for germination are favorable. Switchgrass seed germination responds positively to external sources of no, cyanide and ros. Like most perennial grass seed, switchgrass seed exhibits varying degrees of dormancy that decreases as the seed ages. Postharvest dormancy in recently harvested seed of some switchgrass cultivars can be as high as 95%, and the seed can require up to 2 yr of afterripening to become germinable shen et al. Switchgrass is widely adapted and found throughout the united states with the exception of the west coast.
For example, seed less than one year old may have seed dormancy greater than 60 percent. As a consequence, switchgrass establishment often requires. Alamo switch grass was planted at high or low seeding rate with either high or low dormancy seed levels in 2008 and 2009, respectively. Methods used to break dormancy are letting the seed age for 1 to 2 years after harvest, or seed. Seed dormancy or rest is the internal or innate inhibition of germination of otherwise normal or viable seed even when present under most favourable conditions required for its germination. Breaking seed dormancy of switchgrass panicum virgatum l. Given the large increase in genomic and other resources for switchgrass, it is anticipated that projected molecular studies. Aba, ros and no are key players during switchgrass seed.
We have investigated the influences of prolonged stratification. Aged switchgrass seed lots response to dormancybreaking. The management and use of switchgrass in georgia 2 uga cooperative extension bulletin 58 description switchgrass is a native warm season nws perennial grass that is often grown as a forage crop, natural wildlife habitat, or, increasingly, as a bioenergy crop. Check with seed companies on availability and quality of their seed before making purchases. Douglas and janet grabowski1 introduction switchgrass panicum virgatum l. Come spring, mow before it goes to seed and then till the soil.
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