Sorghum halepense (Johnson grass).

2021 ◽  
Author(s):  
Chris Parker
Keyword(s):  
Competitive Exclusion ◽  
Perennial Grass ◽  
Fire Risk ◽  
High Rate ◽  
Sorghum Halepense ◽  
Invasive Weed ◽  
Field Crops ◽  
Worldwide Distribution ◽  
Johnson Grass ◽  
Wide Range

Abstract S. halepense is a perennial grass which can be cultivated for fodder, but is also an extremely invasive weed with a worldwide distribution. Its extensive spreading rhizome and shoot system and high rate of seed production make it extremely invasive and difficult to eradicate. The species has a number of detrimental effects including: toxicity to grazing stock, fire risk during summer and competitive exclusion of other plants. It reduces soil fertility, acts as a host for crop pathogens and is a known allergen. It is regarded as a serious weed in 53 countries and in a wide range of field crops.

scholarly journals CONTROL OF PERENNIAL GRASSES ON CULTIVATED AND UNCULTIVATED LAND

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1078d-1078
Author(s):  
Bakir A. Al-Juboory
Keyword(s):  
Cynodon Dactylon ◽  
Perennial Grass ◽  
Cyperus Rotundus ◽  
Perennial Grasses ◽  
Bermuda Grass ◽  
Sorghum Halepense ◽  
Johnson Grass ◽  
Successful Control ◽  
Major Factors ◽  
Uncultivated Land

This experiment was conducted to determine effects of herbicides on the control of noxious perennial grass weeds. The results indicate that the rate, timing, duration and number of applications employed were the major factors in the successful control of perennial grass weeds such as Cogon Grass (Imperala cylindrica), Johnson Grass (Sorghum halepense), Bermuda Grass (Cynodon dactylon), Nut Grass (Cyperus rotundus) and Common Red (Phragmites spp.), commonly found in Iraq growing both in cultivated fields and wild on uncultivated land.

THE BIOLOGY OF CANADIAN WEEDS.: 61. Sorghum halepense (L.) PERS.

1983 ◽  
Vol 63 (4) ◽  
pp. 997-1014 ◽  
Author(s):  
S. I. WARWICK ◽  
L. D. BLACK
Keyword(s):  
Biological Information ◽  
Sorghum Halepense ◽  
Southern Ontario ◽  
Forage Crop ◽  
Johnson Grass ◽  
Large Numbers ◽  
Wide Range ◽  
The World ◽  
Self Compatibility ◽  
Vigorous Growth

A review of biological information is provided for Sorghum halepense (L.) Pers., Johnson grass. A native of southern Eurasia to India, S. halepense occurs as a weed in most tropical and temperate areas of the world, and has recently become established in 10 counties in Southern Ontario. Listed as one of the world’s worst weeds, S. halepense infestations result in severe crop losses either from competition or alleleopathic effects and/or by serving as an alternative host for several crop pests. The species is, however, an important forage crop in the southeastern United States and other areas of the world. Johnson grass has several features which contribute to its success as a weed, including the production of extensively creeping rhizomes and large numbers of seeds, rhizomes which regenerate easily if cut into small pieces in cultivation procedures, self-compatibility, seed longevity, seed dormancy and vigorous growth under a wide range of environmental conditions. To date, one population of S. halepense from Brant County, Ontario is known to produce rhizomes which successfully overwinter in Canada. This population would appear to be distinct from the other Ontario populations and is characterized by smaller seeds and seedlings and lower rates of germination. A combination of repeated tillage, proper herbicides and crop rotation will give the best control of Johnson grass.Key words: Sorghum halepense, Johnson grass, biological review

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.

Sustaining Research-Based Practices in Reading

1999 ◽  
Vol 20 (5) ◽  
pp. 263-287 ◽  
Author(s):  
Janette K. Klingner ◽  
Sharon Vaughn ◽  
Marie Tejero Hughes ◽  
Maria Elena Arguelles
Keyword(s):  
Instructional Practices ◽  
High Rate ◽  
Strategic Reading ◽  
School Year ◽  
Wide Range ◽  
Sustained Use ◽  
Development Experience ◽  
Collaborative Strategic Reading ◽  
Research Based Practices ◽  
Over Time

This study examined the extent to which the reading instructional practices learned by a cohort of teachers who participated in an intensive, yearlong professional development experience during the 1994-1995 school year have been sustained and modified over time. Teachers learned three multileveled practices—partner reading, collaborative strategic reading, and making words—that promote gains in reading for students from a wide range of achievement levels. Teachers were observed and interviewed 3 years later to determine the extent to which they continued to implement the practices, the ways in which they modified them, and factors that influenced their sustained use of the practices. With the exception of one teacher, all the teachers sustained one or more of the three practices at a high rate.

Seed germination response of a noxious agricultural weed Echium plantagineum to temperature, light, pH, drought stress, salinity, heat and smoke

2018 ◽  
Vol 69 (3) ◽  
pp. 326 ◽  
Author(s):  
Singarayer Florentine ◽  
Sandra Weller ◽  
Alannah King ◽  
Arunthathy Florentine ◽  
Kim Dowling ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Drought Stress ◽  
Invasive Weed ◽  
Germination Response ◽  
Elevated Salinity ◽  
Wide Range ◽  
Agricultural Weed ◽  
Soil Seedbank ◽  
Response To Temperature ◽  
Salinity Management

Echium plantagineum is a significant pasture weed in the Mediterranean climatic zone of several countries, including Australia. This invasive weed, introduced as an ornamental into Australia (where it is known as Paterson’s curse), quickly became established and is now a significant weed of agriculture. Although E. plantagineum is a well-established, highly competitive weed that thrives under disturbance and is tolerant of a wide variety of conditions, including varying soil moisture and drought, and some aspects of its ecology remain unknown. This study investigated germination response to temperature and light, pH, soil moisture, salinity, and pre-germination exposure of seed to heat and smoke. Temperature was found to be more influential on germination than light and the species is tolerant to a wide range of pH. However, available moisture may limit germination, as may elevated salinity. Management of this weed requires approaches that minimise soil seedbank input or prevent germination of soil seedbanks.

MAIN FEATURES AND TRENDS OF DEVELOPMENT OF THE SERVICE MARKET

2017 ◽  
Author(s):  
Larysa Getman ◽  
Keyword(s):  
Customer Loyalty ◽  
Consumer Choice ◽  
Information Technologies ◽  
Service Sector ◽  
Supply And Demand ◽  
High Rate ◽  
Barriers To Entry ◽  
Relevant Market ◽  
Service Market ◽  
Wide Range

The article discusses approaches to the interpretation of the concept of a service, its specific differences from a physical product and the main features as an object of purchase and sale in the relevant market. Based on the analysis and systematization of existing scientific views, the main features of the service market and the features of the interaction of supply and demand in the service sector are revealed. The practice of functioning of the service market demonstrates the high dynamics of market processes, a pronounced segmentation of demand for services, a high degree of differentiation of services, a high rate of capital turnover and the important role of non-price barriers to entry into the market. The essence and value of the customer's customer loyalty for successful commercial activities and increasing the competitiveness of the manufacturer-supplier of the service has been investigated. Loyalty becomes an indicator of business performance and its ability to innovate. A customer-oriented business philosophy, where a wide range of factors of influence on the formation of customer loyalty is taken into account and used, will allow the company to count on long-term relationships with the consumer and will attract new customers through his positive experience. The possibilities and features of the application of competitive strategies by firms in the field of service activities were analyzed. The main trends in the development of the services market in the current stage, namely the processes of its digitalization, have been investigated. The buyer today is interested not only in price and quality, but also in good service. If a company meets customer service demand through the introduction of chat bots, self- service terminals, mobile applications, etc., then this contributes to the formation of a positive customer experience, which ultimately increases sales. The features and advantages of using information technologies both in business activities and in the implementation of consumer choice have been determined.

scholarly journals Adaptation limits ecological diversification and promotes ecological tinkering during the competition for substitutable resources

2018 ◽  
Vol 115 (44) ◽  
pp. E10407-E10416 ◽  
Author(s):  
Benjamin H. Good ◽  
Stephen Martis ◽  
Oskar Hallatschek
Keyword(s):  
Evolutionary Dynamics ◽  
Competitive Exclusion ◽  
Directional Selection ◽  
Ecological Niches ◽  
Ecological Diversification ◽  
Effective Competition ◽  
Uptake Rates ◽  
Wide Range ◽  
Dynamical Features ◽  
Adaptation Limits

Microbial communities can evade competitive exclusion by diversifying into distinct ecological niches. This spontaneous diversification often occurs amid a backdrop of directional selection on other microbial traits, where competitive exclusion would normally apply. Yet despite their empirical relevance, little is known about how diversification and directional selection combine to determine the ecological and evolutionary dynamics within a community. To address this gap, we introduce a simple, empirically motivated model of eco-evolutionary feedback based on the competition for substitutable resources. Individuals acquire heritable mutations that alter resource uptake rates, either by shifting metabolic effort between resources or by increasing the overall growth rate. While these constitutively beneficial mutations are trivially favored to invade, we show that the accumulated fitness differences can dramatically influence the ecological structure and evolutionary dynamics that emerge within the community. Competition between ecological diversification and ongoing fitness evolution leads to a state of diversification–selection balance, in which the number of extant ecotypes can be pinned below the maximum capacity of the ecosystem, while the ecotype frequencies and genealogies are constantly in flux. Interestingly, we find that fitness differences generate emergent selection pressures to shift metabolic effort toward resources with lower effective competition, even in saturated ecosystems. We argue that similar dynamical features should emerge in a wide range of models with a mixture of directional and diversifying selection.

scholarly journals Cytospora (Diaporthales) in China

2020 ◽  
Vol 45 (1) ◽  
pp. 1-45 ◽  
Author(s):  
X.L. Fan ◽  
J.D.P. Bezerra ◽  
C.M. Tian ◽  
P.W. Crous
Keyword(s):  
New Species ◽  
Host Plants ◽  
Southwest China ◽  
New Combination ◽  
Large Collection ◽  
Dna Phylogeny ◽  
The Past ◽  
Worldwide Distribution ◽  
Wide Range ◽  
Woody Host

Members of the genus Cytospora are often reported as endophytes, saprobes or phytopathogens, primarily causing canker diseases of woody host plants. They occur on a wide range of hosts and have a worldwide distribution. Although several species have in the past been reported from China, the vast majority are not known from culture or DNA phylogeny. The primary aim of the present study was thus to clarify the taxonomy and phylogeny of a large collection of Cytospora species associated with diverse hosts in China. Cytospora spp. were collected in northeast, northwest, north and southwest China, indicating that the cold and dry environments favour these fungi. In this paper, we provide an assessment of 52 Cytospora spp. in China, focussing on 40 species represented by 88 isolates from 28 host genera. Based on a combination of morphology and a six-locus phylogeny (ITS, LSU, act1, rpb2, tef1-α and tub2), 13 new species and one new combination are introduced. The majority of the species investigated here appear to be host-specific, although further collections and pathogenicity studies will be required to confirm this conclusion.

The invasive weed Lantana camara increases fire risk in dry rainforest by altering fuel beds

Weed Research ◽  
2011 ◽  
Vol 51 (5) ◽  
pp. 525-533 ◽  
Author(s):  
Z C BERRY ◽  
K WEVILL ◽  
T J CURRAN
Keyword(s):  
Fire Risk ◽  
Lantana Camara ◽  
Invasive Weed

Population variation in Sorghum halepense, Johnson grass, at the northern limits of its range

1984 ◽  
Vol 62 (9) ◽  
pp. 1781-1790 ◽  
Author(s):  
S. I. Warwick ◽  
B. K. Thompson ◽  
L. D. Black
Keyword(s):  
New York ◽  
Dry Weight ◽  
Population Variation ◽  
Sorghum Halepense ◽  
Johnson Grass ◽  
Allocation Patterns ◽  
Cultivated Species ◽  
Relationship Of ◽  
The Relationship ◽  
Enzyme Patterns

Thirteen populations of Sorghum halepense, Johnson grass, were sampled from fields in Ontario, Canada, and Ohio and New York, United States. Only four of these populations were reported to overwinter as rhizomes. The morphology, phenology, resource allocation patterns, and growth of seedling and mature plants of the overwintering and the non-overwintering populations were compared. Field-collected specimens from the nonoverwintering populations had wider culms and leaves and larger seeds and inflorescences. Analysis of material grown in a 5-month greenhouse trial indicated similar differences. Greenhouse plants from the nonoverwintering populations were also characterized by greater percent emergence, larger and faster growing seedlings, earlier flowering, larger culms and seeds, greater reproductive dry weight per plant, and about 1/10th the rhizome dry weight of overwintering plants. Differences between populations within a biotype were evident for both biotypes, although there was little within-population variation, except in rhizome production, where certain individuals of some nonoverwintering populations did not produce extended rhizomes. Among the five enzymes which were examined electrophoretically, only one, phosphoglucomutase (PGM), showed variable isozyme patterns. No differences in enzyme patterns were apparent between the overwintering and the nonoverwintering biotypes. The relationship of the nonoverwintering populations to the cultivated species, Sorghum bicolor and S. almum, an introgressant between S. halepense and S. bicolor, is discussed.

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