Parthenogenesis was found to be under strong genetic control, dominant over obligatory fertilization. Kentucky bluegrass is a member of the poaceae or grass family. Seed production fields may be swathed and combined out of a cured windrow or it may be direct harvested. Please click on any button to follow a link to that database. This plant may be known by one or more common names in different places, and some are listed above. Seed production peaks in may and june and continues at a lower level thereafter. If apomixis were well understood and harnessed, it could be. Atiners conference paper series agr20120181 kentucky. The ligule is extremely short and square ended, making a contrast with annual meadowgrass and rough meadowgrass poa trivialis in which it is silvery and pointed. Development of kentucky bluegrass for nonburn seed production. However, it is considered an invasive weed in natural grassland ecosystems where it outcompetes native species and reduces biodiversity and alters nitrogen cycling and ecosystem function. Abstract in seed production unless crop residue is removed. Its open, light brown flowerseed head produces much seed. Pdf the effect of auxin treatment on the formation of apomictic endospermless grains in.
The source of this cultivar was a single plant collection made in 1957 at hope, alaska. Runners creep under the surface of the ground and produce upright leafy stems from their ends. Kentucky bluegrass is a cool season, matforming perennial grass that can reach heights up to 4 feet. Plant phenological stage at time of burning greatly influences fire damage to herbaceous plants.
The results are disussed in relation to different stages in apomictic seed production. Evans and watkins 1939 relate the more upright growth form and greater rhizome development of both poa pratensis and poa compressa in. Nugget kentucky bluegrass pdf file poa pratensis, cultivar nugget kentucky bluegrass was released and developed by the university of alaska experiment station in 1966. Yields in rowseeded plots from 1998 and 1999 data were consistently correlated with yield per plant per area in spaced plants in 2002 0. It grows best during cool, moist weather on welldrained, fertile soils and spreads via rhizomes to form a dense sod. Seedhead stems are 18 to 24 inches tall, but can be 4 to 6 inches in height when used for intensive grazing. Cafield burning has traditionally been used to stimulate kentucky node and law 1977 found that yield reductions ranged bluegrass poa pratensis l.
Kentucky and spreading bluegrass reproduce from both seed and rhizomes. Johnson usdaars western regional plant introduction station washington state university usa kentucky bluegrass poa pratensis l. Individual plants can produce 1,050 to 2,250 seeds per plant holm et al. Without postharvest residue removal in late summer or early autumn.
Barserati is a sport and lawn poa pratensis variety suitable for. Poa pratensis genotypes formed both apomictic and sexual seeds. Seed yield, seeds per panicle, panicle number, weight per seed, heading, anthesis, and harvest dates showed strong accession differences on spaced plants in 2002 and 2003. The following databases may contain further information on this name. Germplasm for seed production without field burning by william johnston richard johnson charles golob kathleen dodson matthew nelson gwen stahnke elizabeth guertal openfield burning of kentucky bluegrass poa pratensis l. New efforts to overcome apomixis in poa pratensis l. Poa pratensis and over other quality seeds for sale. Poa pratensis is a perennial, cool season matforming grass. Kbg is generally slow to establish and is often sold in blends with other faster growing grasses e.
Poa pratensis kentucky bluegrass this plant can be weedy or invasive according to the authoritative sources noted below. Turfgrass quality seed yield kgha kentucky bluegrass poa. Kentucky bluegrass is the grass that made sod production possible in northern climates. Poa is greek for fodder and pratensis is latin for meadow infraspecific taxa recognised by the plant list 2016 are poa pratensis var.
In 2008, over 450,000 acres of agricultural land in the willamette valley were in grass seed production, more than onethird of all cropland in the valley. The wide, creeping rootstock produces underground runners and leafy shoots. Cultivated varieties cultivars of poa pratensis are used in britain primarily for amenity grass for lawns, sports turf and roadside verges. Before mowing, kentucky bluegrass can reach about 2 feet high. Pdf genetic control of parthenogenesis in poa pratensis. Inheritance of apomictic seed production in kentucky bluegrass poa pratensis l.
Apomixis, an asexual mode of reproduction, avoids both meiotic reduction and egg fertilization. Inheritance of apomictic seed production in kentucky. Plants profile for poa pratensis kentucky bluegrass. The sensitivity of lolium perenne and poa pratensis to salinity and. Breeders have been able to make controlled crosses and in many cases the resulting crosses are still highly apomictic. Annual flowering of the plants occurred during the 20102011 and 20112012 seasons. Research and performance summary for liberator poa.
In an experiment started in 1965, a plot was seeded to meadow fescue festuca pratensis and another to awnless bromegrass bromus inermis. Its open, light brown flower seed head produces much seed. The kentucky bluegrass is a dark greenblue compared to the applegreen color of poa annua and poa trivialis. Canada bluegrass seed matures uniformly and does not shatter readily making this species easy to harvest. Kentucky bluegrass has long been the most important cool season grass planted as turf. It has been used for lawns, athletic fields, golf course fairways, tees, and rough, and been widely planted for pastures in regions where it thrives. It was one of the many species described in species plantarum by carl linnaeus in 1753. Poa pratensis and viola grypoceras quite common tsuyuzaki and goto, 2001. Lolium perenne and poa pratensis to salinity and drought during the seed germination and under. The most drought and heat tolerant poa pratensis ever. This perennial grass produces flowering culms that are 12. Selection for seed yield components had a variable response in 2008.
By means of a new method, plants of poa pratensis can be classified rapidly and reliably as to whether they are capable or incapable of parthenogenesis. Seed production generally requires the mating of opposite sex gametes. This study investigated the influence of different soil tillage practices on persistence of newly shed seeds of two grass species, poa pratensis and lolium perenne. Residue management, seed production, crop development, and. Economic conditions have severely influenced the grass seed market. In 2008, over 450,000 acres of agricultural land in the willamette valley were in grassseed production, more than onethird of all cropland in the valley. Leaving the seeds at or close to the soil surface reduced seed survival of both.
Turfgrass quality seed yield kgha kentucky bluegrass. The plots were not treated with mineral fertilisers. Poa pratensis forms a valuable pasture plant characteristic of welldrained fertile soil. It is ready to harvest when the field has reached a uniform golden color. Pdf genetic control of parthenogenesis in poa pratensis l.
The name kentucky bluegrass derives from its flower heads, which are blue when the plant is allowed to grow to its natural height of two to. Kentucky blue grass hereinafter kbg is best grown in fertile, medium moisture, welldrained soils in full sun to part shade. Kentucky bluegrass poa pratensis is a rhizomatous grass that is regarded as a crop in some systems, but as a weed in others. Johnston department of crop and soil sciences washington state university usa r. The essential feature of apomixis is that an embryo is formed autonomously by parthenogenesis from an unreduced egg of an embryo sac generated through apomeiosis. Its flat green, often greyish green leaves grow in short tufts or knit together to form a.
Bridger plant materials center maintains generation 1 g1 seed which is made available to seed growers for production of certified g2 and g3 seed majerus and holzworth, 2003. Pdf identification of apomixis in the kentucky bluegrass poa. Prefers cool climates, neutral to slightly acidic soils, frequent watering 11. Barserati is the best performing poa pratensis in heat and drought and has the best recovery after heat and drought stress. Seed yield, development, and variation in diverse poa. Distribution poa pratensis grows along roadsides throughout much of alaska. Kentucky bluegrass, kentucky bluegrass poa pratensis. It is deep rooted and creeps extensively through the soil with a network of creeping rhizomes. Pdf inheritance of apomictic seed production in kentucky. Germplasm for seed production without field burning fig. Some fields of poa pratensis can be traced as having lived for 60 years usda, 1948. The plant list does not attempt to include all infraspecific taxa. Poa pratensis forms a valuable pasture plant, characteristic of welldrained, fertile soil.
The influence of light regimes during floral development on apomictic seed production and on variability in resulting seed progenies of poa ampla and poa pratensis. Openfield burning of kentucky bluegrass poa pratensis l. It grows best during cool, moist weather on welldrained, fertile soils and. Longevity of seeds of poa pratensis and lolium perenne as.
Poa pratensis has a fairly prominent midvein center of the blade. For a pure kbg lawn, it is best to mix and sow the seed of 35 different kbg cultivars. It is highly valued as a pasture and turf grass, particularly in golf courses. The name kentucky bluegrass derives from its flower heads which are blue when the plant is allowed to grow to its natural height of two to. In this context, seeds of previously grown grass species or varieties are particularly important. Large varietal differences in na concentration occur in dactylis glomerata and lolium perenne, smaller variation in festuca arundinacea, and very little variation in festuca pratensis fig. Culms of the plant are erect to decumbent at the base, slender and wiry, and nearly circular to slightly flattened.
The selected sexual plants lack all genesalleles responsible for parthenogenesis, while the polyploid apomictic varieties investigated. Kentucky bluegrass germplasm evaluation for nonburn seed. Reubens was released by the jacklin seed company, post falls, idaho in 1976. Evolution and adaptedness in a facultatively apomictic. The process of apomictic seed production involves the formation of embryo sacs without. It is also used for making lawns in parks and gardens. Id and control of annual bluegrassid and control of annual. Seedlings mature in the fall, overwinter in a vegetative state, and. Smoothstalked meadowgrass is a perennial grass of short to medium height. If apomixis were well understood and harnessed, it could. After 30 yr of burial, the average total density was 1215 seeds m.
Seed heads can form in plants that are six weeks old, and viable seed production can begin a few days after pollination. Usda nrcs national plants data center alternate names june grass, paneion pratense, poa anceps, poa angustifolia var. They will establish in seed production fields and are difficult to identify and rogue. Although the species is spread over all of the cool, humid parts of the united states, it is not native to north america. Residue management, seed production, crop development. Seed yields range from 250500 pounds per acre on irrigated. Kentucky bluegrass poa pratensis grass family poaceae description. The biomass produced annually by the two plants was low about 100 kg of dry matter ha 1. Two pi accessions, pi 368241 and pi 371775, show promise of being able to provide good turfgrass quality and seed yield under nonburn management fig. Festuca pratensis an overview sciencedirect topics.
Research and performance summary for liberator poa pratensis. But at the same time i showed that pollination is necessary for the development of the ovule into seed, the pollen as a rule only inducing an apomictic seed formation. Phenotypic evaluation of kentucky bluegrass poa pratensis l. Before seeding, the second plot was covered with a peat layer. Athletic fields, sod production, sod seed, golf turf blends and mixtures super elite status. The slender culms are light green, terete to slightly flattened, glabrous, unbranched, and more or less erect. Poa pratensis, commonly known as kentucky bluegrass or blue grass, smooth meadowgrass, or common meadowgrass, is a perennial species of grass native to practically all of europe, north asia and the mountains of algeria and morocco. Overview appearance poa pratensis, commonly known as kentucky bluegrass or common meadowgrass, is a perennial species of grass. In general, as new foliage of perennial grasses reaches full development major food reserves have been depleted, so that plants are injured most from fires occurring at this time 24, 93. The seedhead has an open shape like a pyramid and produces many small seeds.