Effect of environmental factors on rhizome bud germination and shoot emergence of invasive Imperata cylindrica

Laboratory and greenhouse studies were conducted to determine the effect of temperature, soil moisture, light, planting depth, and rhizome water content on shoot emergence and vegetative growth of alligatorweed. Optimum shoot emergence and growth occurred at constant 30 C, and no shoot emergence was found below constant 5 C. A maximum shoot emergence of 93% occurred at constant soil moisture of 30% with temperatures of 10 to 35 C. Shoot emergence and growth decreased as rhizome water content decreased, and shoot emergence did not occur below a rhizome water content of 20%. Shoot emergence and growth decreased with burial depth; shoot emergence was above 90% when rhizomes were buried 0.5 to 1.0 cm deep compared to 16% when they were buried 18 cm deep. Alligatorweed shoot emergence and vegetative growth were not significantly affected by light. In the fields, shoot emergence began in late March and culminated in May and June. These data help explain why this species is most commonly found in crop fields, orchards, roadsides, rivers, lakes, ponds, and irrigation canals. This information may aid in the development of more effective management measures, such as bringing alligatorweed rhizomes to the surface or below 20 cm deep to restrain its emergence and growth at winter or summer plowing.

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Factors Limiting the Distribution of Cogongrass,Imperata cylindrica, and Torpedograss,Panicum repens

Weed Science ◽

10.1017/s0043174500075433 ◽

1988 ◽

Vol 36 (5) ◽

pp. 577-582 ◽

Cited By ~ 21

Author(s):

John W. Wilcut ◽

Roland R. Dute ◽

Bryan Truelove ◽

Donald E. Davis

Keyword(s):

Cultural Practices ◽

Morphological Characteristics ◽

The United States ◽

Imperata Cylindrica ◽

Axillary Buds ◽

Viable Seed ◽

Laboratory Studies ◽

Bud Formation ◽

Panicum Repens ◽

Shoot Emergence

Greenhouse, growth chamber, and laboratory studies were conducted to determine anatomical and morphological characteristics and cultural practices limiting the distribution of cogongrass, torpedograss, and johnsongrass in the United States. Cogongrass did not produce axillary buds along most of the rhizome nor regenerate when apical six-node-long rhizome segments were buried deeper than 8 cm. Both torpedograss and johnsongrass produced axillary buds along the entire lengths of their rhizomes. Torpedograss shoot emergence decreased at burial depths between 8 and 16 cm. Shoot emergence from johnsongrass rhizomes was not affected by burial as deep as 16 cm. Rhizomes of all three species were tolerant of desiccation. Cogongrass grew better in soil at pH 4.7 than in soil at pH 6.7, whereas torpedograss and johnsongrass grew equally well in either pH. It is postulated that cogongrass spread is limited by lack of axillary bud formation on most of the rhizome and the inability of rhizomes to send up new shoots if buried deeper than 8 cm. These factors could account for the intolerance of cogongrass to cultivation. Torpedograss appears to spread only vegetatively due to the lack of viable seed production.

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Chlormequat Chloride (CCC) Pretreatments May Enhance Quackgrass (Elytrigia repens) Control with Sethoxydim

Weed Technology ◽

10.1017/s0890037x00039580 ◽

1994 ◽

Vol 8 (3) ◽

pp. 499-507 ◽

Cited By ~ 3

Author(s):

K. Neil Harker ◽

John S. Taylor

Keyword(s):

Field Experiments ◽

Axillary Buds ◽

Effective Control ◽

Research Station ◽

Chlormequat Chloride ◽

Elytrigia Repens ◽

Bud Sprouting ◽

Rhizome Bud ◽

Rhizome Buds ◽

Shoot Emergence

Laboratory, greenhouse, and field experiments were conducted at the Lacombe Research Station to determine if CCC, ethephon, or CCC/ethephon had direct activity on quackgrass rhizome buds, and to determine if foliar applications of CCC/ethephon could predispose quackgrass to more effective control with sethoxydim. CCC, ethephon, and CCC/ethephon had growth regulating effects on the axillary buds and the apex of detached quackgrass rhizomes. CCC increased rhizome bud sprouting on rhizomes with the apex excised, but not on rhizomes with an intact apex. Ethephon or CCC/ethephon inhibited bud sprouting on rhizomes with an intact or excised apex. CCC/ethephon, but not CCC or ethephon alone, increased rhizome elongation on rhizomes with intact apices. In the greenhouse, pretreatments of CCC/ethephon increased sethoxydim activity on quackgrass rhizome buds and caused lower shoot emergence from one-bud rhizome segments. Results of field experiments were less consistent than those in the greenhouse. However, sometimes CCC or CCC/ethephon pretreatments resulted in increased quackgrass control in the field with sethoxydim.

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Simulation of shoot emergence pattern of cogongrass (Imperata cylindrica) in the humid tropics

Weed Science ◽

10.1614/ws-03-146r1 ◽

2004 ◽

Vol 52 (6) ◽

pp. 961-967 ◽

Cited By ~ 3

Author(s):

Friday Ekeleme ◽

Frank Forcella ◽

David W. Archer ◽

David Chikoye ◽

I. Okezie Akobundu

Keyword(s):

Perennial Grass ◽

Imperata Cylindrica ◽

Weibull Function ◽

Hydrothermal Time ◽

Southwestern Nigeria ◽

Forest Zone ◽

Southeastern Nigeria ◽

Humid Forest ◽

Emergence Pattern ◽

Shoot Emergence

Cogongrass is a noxious perennial grass that has invaded many countries in the tropical and subtropical regions of the world. Its management has been a significant challenge because of large rhizome and bud reserves in the soil. The emergence pattern of this weed under field conditions has received little attention. Field trials were conducted in 2002 and 2003 in the humid forest zone of southeastern Nigeria to model shoot emergence. The experiment had four treatments: (1) count and tag crop-free cogongrass shoots, (2) count and suppress crop-free cogongrass shoots with paraquat, (3) count and cut crop-free cogongrass shoots, and (4) count and cut cogongrass shoots in cultivated corn. The rationale for these treatments was to determine the effect of different monitoring techniques on shoot emergence of cogongrass. The development of the model was based on hydrothermal time, which was calculated from soil moisture and soil temperature at a 2-cm depth. A Weibull function was fitted to cumulative percent shoot emergence values of Treatment 4 and hydrothermal time. The model closely fit the observed pattern of cogongrass shoot emergence (r2= 0.95,n= 36). It also predicted shoot emergence satisfactorily in six treatments (r2> 0.85, P < 0.001,n= 7 in each treatment) that simulated farmers' practices in southwestern Nigeria. This is the first model developed for cogongrass shoot emergence based on hydrothermal time under field observations. The model should facilitate further analyses of cogongrass emergence patterns and the timing of its management.

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Reductionist thinking and animal models in neuropsychiatric research

Behavioral and Brain Sciences ◽

10.1017/s0140525x18001231 ◽

2019 ◽

Vol 42 ◽

Cited By ~ 1

Author(s):

Nicole M. Baran

Keyword(s):

Animal Models ◽

Mental Disorders ◽

Environmental Factors ◽

Neuropsychiatric Disorders ◽

Model Organisms ◽

Developmental Genetic ◽

Term Study ◽

Genetic And Environmental Factors ◽

Mechanisms Of Plasticity

AbstractReductionist thinking in neuroscience is manifest in the widespread use of animal models of neuropsychiatric disorders. Broader investigations of diverse behaviors in non-model organisms and longer-term study of the mechanisms of plasticity will yield fundamental insights into the neurobiological, developmental, genetic, and environmental factors contributing to the “massively multifactorial system networks” which go awry in mental disorders.

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The dual nature of obesity in metabolic programming: quantity versus quality of adipose tissue

Clinical Science ◽

10.1042/cs20201028 ◽

2020 ◽

Vol 134 (18) ◽

pp. 2447-2451

Author(s):

Anissa Viveiros ◽

Gavin Y. Oudit

Keyword(s):

Adipose Tissue ◽

Environmental Factors ◽

Maternal Obesity ◽

Metabolic Programming ◽

Dual Nature ◽

Prevalence Of Obesity ◽

Adipose Tissue Volume ◽

Males And Females ◽

Metabolically Healthy

Abstract The global prevalence of obesity has been rising at an alarming rate, accompanied by an increase in both childhood and maternal obesity. The concept of metabolic programming is highly topical, and in this context, describes a predisposition of offspring of obese mothers to the development of obesity independent of environmental factors. Research published in this issue of Clinical Science conducted by Litzenburger and colleagues (Clin. Sci. (Lond.) (2020) 134, 921–939) have identified sex-dependent differences in metabolic programming and identify putative signaling pathways involved in the differential phenotype of adipose tissue between males and females. Delineating the distinction between metabolically healthy and unhealthy obesity is a topic of emerging interest, and the precise nature of adipocytes are key to pathogenesis, independent of adipose tissue volume.

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Shared Responsibilities for Full Participation in Society: Planning Further Integration of the ICF Into AAC

Perspectives of the ASHA Special Interest Groups ◽

10.1044/persp1.sig12.83 ◽

2016 ◽

Vol 1 (12) ◽

pp. 83-93 ◽

Cited By ~ 1

Author(s):

Mary Blake Huer ◽

Travis T. Threats

Keyword(s):

Environmental Factors ◽

Augmentative And Alternative Communication ◽

Functional Limitations ◽

Community Support ◽

World Health ◽

International Classification Of Functioning ◽

Personal Factors ◽

Social Service Agencies ◽

Persons With Disabilities ◽

Full Participation

The World Health Organization's (WHO's) 2001 International Classification of Functioning Disability and Health (ICF) has as one of its central tenets the full inclusion of persons with disabilities in society. It acknowledges the need for medical and rehabilitation intervention in its biopscychosocial framework. However, the WHO realizes that society must do its part to facilitate this full participation and empowerment. Persons with complex communication needs (PWCCN) often need augmentative and alternative communication (AAC) in order to express themselves. However, in order to access and successfully use AAC, PWCCN need access to the necessary AAC devices and services, as well as a willing society to interact with them as full contributing members of society. The factors outside of a person's specific physical and/or cognitive functional limitations are addressed in the ICF via the Personal and Environmental Factors. Personal Factors include the individual's personality traits, lifestyle, experiences, social/educational/professional background, race, gender, and age. Environmental Factors include community support systems, social service agencies, governments, social networks, and those persons that interact with the PWCCN. This article addresses the sociopolitical influences on PWCCN and their functioning from a human rights perspective. The necessary introspective role of speech-language pathologists in this process is explored.

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