The influence of sowing method on perennial grass establishment. II. Seedbed microenvironment, germination and emergence

1989 ◽  
Vol 40 (2) ◽  
pp. 313 ◽  
Author(s):  
WD Bellotti ◽  
GJ Blair
Keyword(s):  
Perennial Grass ◽  
Germination Percentage ◽  
Perennial Grasses ◽  
Pass Band ◽  
Viable Seed ◽  
Herbicide Treatment ◽  
Wide Range ◽  
Soil Temperatures ◽  
Herbicide Mixture ◽  
Moisture Conditions

'Demeter' tall fescue (Festuca amndinacea Schreb.) and 'Victorian' perennial ryegrass (Lolium perenne L.) were sown separately into a white clover (Trifolium repens L.) dominant pasture. Eight sowing methods were compared to assess the ability of perennial grasses to germinate and emerge from direct drill sowing methods relative to conventional seedbed and aerial sowing methods. Within direct drill treatments, two drill implements were factorially combined with three herbicide treatments. Soil temperature and moisture conditions were cold and moist, but generally adequate for emergence of temperate pasture species. In-groove soil moisture content was always greatest in the disc plus herbicide treatment. Differences in seed level soil temperatures were minor, although diurnal fluctuations were greatest in the aerial plus herbicide treatment. Emergence of ryegrass at 50 days after sowing was similar in all sowing methods (67.9-93.9% viable seed sown) except for the aerial plus herbicide and disc plus band herbicide methods (23.4 and 44.0% of viable seed sown). There was a wide range of emergence percentages for fescue at 50 days after sowing (17.8-69.2% viable seed sown) and again the aerial plus herbicide treatment was lowest. One-pass, band spraying of a paraquat.diquat plus dicamba herbicide mixture at the time of sowing impaired the germination percentage of ryegrass seeds sown with the disc drill. Apart from the aerial plus herbicide treatment, sufficient seedlings passed through the germination/emergence filter in all direct drill and cultivated seedbed treatments to provide for a productive grass-based pasture.

Factors affecting red-osier dogwood seed germination

1992 ◽  
Vol 70 (5) ◽  
pp. 1012-1016 ◽  
Author(s):  
S. N. Acharya ◽  
C. B. Chu ◽  
R. Hermesh ◽  
G. B. Schaalje
Keyword(s):  
Seed Germination ◽  
Germination Percentage ◽  
Collection Site ◽  
Moisture Condition ◽  
Seed Formation ◽  
Factors Affecting ◽  
Year Effect ◽  
Wide Range ◽  
Cornus Stolonifera ◽  
Moisture Conditions

Seeds from 55 populations of native Alberta red-osier dogwood (Cornus stolonifera Michx.) were collected over 2 years (1984 and 1985) to determine the range of variability for seed germination and the effect of ecoregion and moisture conditions in the collection sites on this trait. Each year the unscarified seeds were stored at 3 °C for 30 days, stratified at 3 °C for an additional 30 days and then incubated on an 8 h light: 16 h dark cycle at a temperature of 25:10 °C (light:dark) for germination. A wide range of germination percentages was observed among populations collected in any 1 year. However, the variability was not due to the ecoregion or moisture condition of the collection site. Germination percentage of populations collected in 1984 and 1985 formed five and seven groups, respectively. A study involving eight sites that were common to 1984, 1985, and 1986 revealed a significant effect of population on seed germination. This population effect was not obscured by the combined effects of year, precipitation, temperature, and seed size. The year effect was significant only when population was used as a covariate. Precipitation during seed formation significantly influenced germination performance even after adjustments were made for population and year. Seed germination in red-osier dogwood appears to be influenced by the population from which the seeds are collected and by yearly environmental fluctuations. Therefore, germination studies in this species must include seeds from diverse populations collected over several years. Key words: red-osier dogwood, Cornus stolonifera Michx., germination, population, environment.

scholarly journals Integrated Management of Perennial Pepperweed (Lepidium latifolium)

2008 ◽  
Vol 1 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Rob G. Wilson ◽  
Debra Boelk ◽  
Guy B. Kyser ◽  
Joseph M. DiTomaso
Keyword(s):  
Integrated Management ◽  
Perennial Grass ◽  
Management Strategies ◽  
Site Preparation ◽  
Perennial Grasses ◽  
Flower Bud ◽  
No Till ◽  
Wide Range ◽  
Grass Establishment ◽  
Native Perennial Grass

AbstractPerennial pepperweed is invasive throughout California. It thrives in a wide range of environments and is a common weed in floodplains, pastures, wetlands, and roadsides. In disturbed areas, perennial pepperweed rapidly forms monotypic stands with a thick litter layer. These infestations not only out-compete other vegetation, but prevent re-establishment of desirable species even after perennial pepperweed control. This experiment examined integrated management strategies with the goal of maximizing perennial pepperweed control and establishment of desirable native vegetation. The experiment was conducted at two sites in Lassen County, CA. Both sites were heavily infested with perennial pepperweed and lacked competing vegetation. The experimental design was a split-split-randomized block with four replications. Site preparation treatments included winter burning, summer and fall mowing, winter grazing, and fall disking. These treatments were designed to remove thatch to facilitate herbicide application and reseeding of desirable perennial grasses. Herbicide treatments included chlorsulfuron, 2,4-D, or glyphosate applied at the flower bud stage. Revegetation treatments included no seeding and no-till seeding of native perennial grasses. Most site preparation plus herbicide combinations reduced perennial pepperweed cover > 85% compared to the untreated control, although treatment efficacy was variable between sites and years. Burning, grazing, mowing, or disking in combination with herbicide treatment and no-till seeding was necessary for successful native perennial grass establishment. Burning or mowing with yearly 2,4-D applications for 3 yr gave the best combination of perennial pepperweed control and native grass establishment. Chlorsulfuron caused chlorosis and stunting to western wheatgrass, basin wildrye, and beardless wildrye at both sites when applied the spring before seeding. No treatment offered complete weed control, suggesting follow-up spot herbicide applications are needed for long-term perennial pepperweed suppression. These results provide several successful integrated strategies for control of perennial pepperweed and revegetation to a desired native perennial grass community.

scholarly journals Suitability of Different Gels as Seed Carriers and Germination and Emergence Promoters in Processing Carrots

HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 612-617 ◽  
Author(s):  
Rowan D. Briscoe ◽  
Rajasekaran R. Lada ◽  
Claude D. Caldwell ◽  
Kevin Sibley
Keyword(s):  
Seed Germination ◽  
Guar Gum ◽  
Germination Percentage ◽  
Stand Establishment ◽  
Yield And Quality ◽  
Different Types ◽  
Soil Temperatures ◽  
Moisture Conditions

Stand establishment is critical for optimizing yield and quality in carrots. Low soil temperatures and moisture conditions often challenge seed germination and emergence. Providing an artificial exosperm with appropriate germination promoters, stress conditioners and growth invigorators to the seed may facilitate uniform germination and emergence. Germination patterns and velocity of germination of `Oranza' carrot was studied. Seeds were mixed in different types of gels at various ratios and incubated at either 5 or 20 °C. Gels used were Laponite RD, Laponite RDS, guar gum, algenic acid, and agar. Data on germination percentage was collected and the velocity of germination was calculated. Germination was delayed at 5 °C. Both at 5 and 20 °C, Laponite RD promoted and enhanced germination and vigor, and resulted in the highest mean germination percentage (90% at 20 °C and 89% at 5 °C). Laponite RD at 2.5% has shown an overall advantage in germination percentage (94% at 20 °C and 87% at 5 °C) over other gel types and concentrations.

Changes in the Quantitative Floristics in Some Astrebla Spp. (Mitchell Grass) Communities in South-Western Queensland in Relation to Trends in Seasonal Rainfall

1981 ◽  
Vol 29 (5) ◽  
pp. 533 ◽  
Author(s):  
DM Orr
Keyword(s):  
Relative Abundance ◽  
Perennial Grass ◽  
Grazing Pressure ◽  
Perennial Grasses ◽  
Seasonal Rainfall ◽  
Individual Species ◽  
Botanical Composition ◽  
Basal Cover ◽  
Wide Range ◽  
Annual Grasses

Seasonal changes in the quantitative floristics at a wide range of Astrebla grassland sites in south-western Queensland were monitored between 1972 and 1980 with a wheel point apparatus. Changes in the floristics were measured in terms of both relative abundance and basal cover. A large increase in the relative abundance of perennial grasses, particularly Aristida latifolia, Astrebla spp. and Dichanthium sericeum, occurred between 1972 and 1976. This increase was at the expense of annual grasses and forbs which declined in both relative abundance and number of genera present. The relative abundance of perennial grasses declined between 1978 and 1980 and this was associated with a large increase in the forbs such as Daucus glochidiatus and Plantago spp., particularly at southern sites. The contribution of annual grasses to botanical composition remained low throughout the period. Total basal cover differed between years although these differences were not significant. As perennial grass, particularly Astrebla spp., was the major vegetation component of total basal cover, changes in the latter were associated mainly with changes in the basal cover of Astrebla spp. Changes in the contribution of individual species to total basal cover were related to changes in the relative abundance of those species. Changes in botanical composition in Astrebla grassland may be influenced more by trends in seasonal rainfall than by grazing pressure.

Macropods, feral goats, sheep and cattle. 2. Equivalency in what and where they eat

2019 ◽  
Vol 41 (6) ◽  
pp. 519 ◽  
Author(s):  
Lester Pahl
Keyword(s):  
Diet Composition ◽  
Perennial Grass ◽  
Climatic Conditions ◽  
Perennial Grasses ◽  
The Other ◽  
Green Leaf ◽  
Wide Range ◽  
Annual Grasses

The extent to which sheep, cattle, feral goats, red kangaroos, western grey kangaroos, euros and eastern grey kangaroos are equivalent in their use of the Australian southern rangelands is partly dependent on the extent to which their diets and foraging areas overlap. These herbivores all eat large amounts of green annual grasses, ephemeral forbs and the green leaf of perennial grasses when they are available. Overlap in use of these forages by all seven herbivores is concurrent and high. As the abundance of these preferred forages declines, sheep, cattle and feral goats consume increasing amounts of mature perennial grasses and chenopod and non-chenopod perennial forbs. Red kangaroos and western grey kangaroos continue to graze mature perennial grasses longer than sheep, cattle and feral goats, and only switch to perennial forbs when the quantity and quality of perennial grasses are poor. Consequently, overlap in use of perennial forbs by sheep, cattle, feral goats, red kangaroos and western grey kangaroos is sequential and moderately high. When palatable perennial forbs are eaten out, the diets of all herbivores except feral goats comprise predominantly dry perennial grass, and overlap is again concurrent and high. In comparison, feral goats have higher preferences for the browse of a wide range of shrubs and trees, and switch to these much earlier than the other herbivores. When perennial grasses and perennial forbs become scarce, sheep, feral goats and cattle browse large shrubs and trees, and overlap is sequential and high. If climatic conditions remain dry, then red and western grey kangaroos will also browse large shrubs and trees, but overlap between them, sheep, cattle and goats is sequential and low. In contrast to the other herbivores, the diets of euros and eastern grey kangaroos are comprised predominantly of perennial grasses, regardless of climatic conditions. As for diet composition, concurrent overlap in foraging distributions of sheep, cattle, feral goats and the four species of macropods is often low. However, over periods of several months to two or three years, as climatic conditions change, overlap in foraging distributions is sequential and high. While equivalency in what and where these herbivores eat is not quantifiable, it appears to be high overall. This is particularly so for perennial grass, which is the dominant forage for herbivores in the southern rangelands.

Population dynamics and stability of Stylosanthes hamata cv. Verano in grazed pastures

1982 ◽  
Vol 33 (1) ◽  
pp. 63 ◽  
Author(s):  
CJ Gardener
Keyword(s):  
Perennial Grass ◽  
Perennial Grasses ◽  
Botanical Composition ◽  
Grazed Pastures ◽  
Stylosanthes Hamata ◽  
Wide Range ◽  
Annual Grasses ◽  
Seed Reserves ◽  
Stable Association

The longevity, regeneration and seed reserves of Stylosantes hamata cv. Verano were studied in grazed pastures at Lansdown, north Queensland, over a 9-year period. Stability was assessed in terms of frequency of appearance and fluctuations in botanical composition. Plants proved short-lived, with a half-life of only 3 months. The majority therefore died in their seedling year, and only 0.03 % survived to the end of the third year. In most years, S. hamata had to re-establish almost entirely from seed. Despite this, S. hamata was a highly persistent legume in the long term owing to its consistently high seed reserves and ready regeneration from seed. In one paddock, for example, it re-established in all quadrats after disappearing from 76% of them the previous year. This long-term persistence was not, however, reflected in yield stability; the content of S. hamata in one paddock changed from 6 to 68% in consecutive years. Low legume yields were recorded when seedlings of S, hamata competed poorly with the annual grasses. Higher yields occurred when more than 20 % of the population comprised perennial S. hamata plants. Retention of the perennial grasses reduced the amplitude of the fluctuations in yields of S. hamata. The perennial grass and S. hamata formed an intimate and stable association. There were only small effects of stocking rate and superphosphate on the persistence of S. hamata, which suggests that the legume is highly tolerant of a wide range of management levels, although more precise management is needed for high animal production.

Functional Environment of Downy Brome Communities in Relation to Weed Control and Revegetation

Weed Science ◽  
1970 ◽  
Vol 18 (1) ◽  
pp. 154-162 ◽  
Author(s):  
Raymond A. Evans ◽  
H. Richard Holbo ◽  
Richard E. Eckert ◽  
James A. Young
Keyword(s):  
Soil Moisture ◽  
Weed Control ◽  
Perennial Grass ◽  
Critical Periods ◽  
Downy Brome ◽  
Weed Growth ◽  
Control Growth ◽  
Available Soil Moisture ◽  
Soil Temperatures ◽  
Moisture Conditions

We measured some of the more important biologic and microclimatic parameters of the functional environment of downy brome (Bromus tectorumL.) communities during the establishment period of seedlings of intermediate wheatgrass (Agropyron intermedium(Host) Beauv., var. Amur). These measurements were made in relation to weed control and seeding treatments. Weed growth and establishment of replacement vegetation were directly related to available soil moisture and favorable temperatures in the immediate environment of growing plants. Lack of available soil moisture during critical periods of the growing season was the major deterrent to seeding success. The limited precipitation stored as soil moisture was available to perennial grass seedlings where weeds were controlled. Without weed control, growth of downy brome preempted the effective precipitation, and moisture became limiting for growth of perennial grass seedlings. Seeding in furrows, along with weed control, further improved moisture conditions for the seedlings. Also, use of furrows enhanced seedling growth by lowering maximum air and soil temperatures in the seedlings' immediate environment.

6. Perennial grasses as a viable biofuel source in eastern Ontario

2018 ◽  
Author(s):  
Jason LeBlanc
Keyword(s):  
Perennial Grass ◽  
Perennial Grasses ◽  
Nitrogen Fertilizers ◽  
Bioenergy Crops ◽  
Grass Species ◽  
Soil Conditions ◽  
N2o Emissions ◽  
Soil Processes ◽  
Wide Range ◽  
Bioenergy Systems

Climate change and energy security issues have made renewable energy production an important global issue. Bioenergy crops may be able to provide a large amount of the world’s energy needs; therefore it is important to determine their potential for viable and sustainable use. Perennial grasses are an ideal bioenergy crop because they grow quickly across a wide range of climatic and soil conditions. Nitrogen based fertilizers are often used to increase productivity but overuse can lead to excessive nitrous oxide (N2O) emissions, a greenhouse gas (GHG) 300 times more potent that carbon dioxide (CO2). Fertilizing becomes counterproductive when N2O emissions outweigh the benefit gained from reduction in CO2 emissions.      Three perennial grass species (Panicumr virgatum, Schizachyrium scoparium and Andropogon gerardii) were grown in collaboration with Lafarge Cement in Bath, Ontario. Each species was grown under three different fertilization regimes: 0, 50 and 150 lbs/acre of nitrogen as urea. Results of one study indicate that low levels of fertilizer addition enhance the GHG benefits of the grass, but results from another site suggest no benefit.       Our current research is exploring the importance of various soil processes to production of GHG’s in these perennial grass bioenergy systems, and whether the grasses alter soil conditions to favor certain soil processes. The information gained will help to further predict the feasibility of using nitrogen fertilizers to enhance production in these bioenergy systems and the overall viability of bioenergy crops for cement manufacturing and other applications.

A survey of the natural pastures of the Trangie District, New South Wales, with particular reference to the grazing factor.

1953 ◽  
Vol 4 (1) ◽  
pp. 1 ◽  
Author(s):  
EF Biddiscombe
Keyword(s):  
Perennial Grass ◽  
Grazing Intensity ◽  
Basal Area ◽  
Grazing Pressure ◽  
Perennial Grasses ◽  
Forage Production ◽  
South Wales ◽  
Wide Range ◽  
Grazing Intensities ◽  
Summer Maximum

The Trangie district has a rainfall of 1,750 points with a slight summer maximum, a high relative variability of rainfall, and high summer temperatures. Disclimax pasture communities produced by a range of sheep grazing intensities operative during the past 20-30 years are described. On light soils ungrazed pasture comprises a wide range of perennial grasses. Light grazing (1 sheep per 2 acres) gives increased dominance by Stipa fulcata. With successive increases in grazing pressure Chloris acicdaris and Stipa setacea become conspicuous in turn, only to be virtually replaced by Chloris trumata as grazing intensity reaches 1 sheep per 0.5 acre. On heavy soils Stipa aristiglumis is dominant under light grazing. With increased rate of stocking, first Sporobolus caroli and then Stipa setacea gain dominance. At the highest stocking rates all these species are largely replaced by Chloris truncata. Throughout the sere the number of species is far more restricted than on the light soils. The striking feature of these results is that though botanical composition of the perennial grass component on light and heavy soils respectively is vastly different under light grazing, it becomes similar under heavy grazing and almost identical under severe grazing. Degenerative changes common to pastures of both soil groups under increasing grazing pressure are the decline in density and basal area of the perennial grass component, the greater population of winter and summer annuals, and the declining contribution of perennial grasses to green forage production in the spring. The basis of these findings is firstly the measurement of basal area, density and yield of perennial grasses, and density and yield of annual species in pastures of varying stocking history, and secondly, the measurement of pasture composition in relation to increasing distance from watering points.

scholarly journals Breeding Strategies to Improve Miscanthus as a Sustainable Source of Biomass for Bioenergy and Biorenewable Products

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 673 ◽  
Author(s):  
John Clifton-Brown ◽  
Kai-Uwe Schwarz ◽  
Danny Awty-Carroll ◽  
Antonella Iurato ◽  
Heike Meyer ◽  
...  
Keyword(s):  
Significant Contribution ◽  
Perennial Grass ◽  
Time Frame ◽  
Eastern Asia ◽  
Germplasm Collections ◽  
Naturally Occurring ◽  
Wide Range ◽  
Yield Quality ◽  
Short Time ◽  
Commercial Expansion

Miscanthus, a C4 perennial grass native to Eastern Asia, is being bred to provide biomass for bioenergy and biorenewable products. Commercial expansion with the clonal hybrid M. × giganteus is limited by low multiplication rates, high establishment costs and drought sensitivity. These limitations can be overcome by breeding more resilient Miscanthus hybrids propagated by seed. Naturally occurring fast growing indigenous Miscanthus species are found in diverse environments across Eastern Asia. The natural diversity provides for plant breeders, the genetic resources to improve yield, quality, and resilience for a wide range of climates and adverse abiotic stresses. The challenge for Miscanthus breeding is to harness the diversity through selections of outstanding wild types, parents, and progenies over a short time frame to deploy hybrids that make a significant contribution to a world less dependent on fossil resources. Here are described the strategies taken by the Miscanthus breeding programme at Aberystwyth, UK and its partners. The programme built up one of the largest Miscanthus germplasm collections outside Asia. We describe the initial strategies to exploit the available genetic diversity to develop varieties. We illustrate the success of combining diverse Miscanthus germplasm and the selection criteria applied across different environments to identify promising hybrids and to develop these into commercial varieties. We discuss the potential for molecular selections to streamline the breeding process.

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