The Short-Range Movement of Scirtothrips dorsalis (Thysanoptera: Thripidae) and Rate of Spread of Feeding Injury Among Strawberry Plants

2020 ◽  
Author(s):  
Babu R Panthi ◽  
Justin M Renkema ◽  
Sriyanka Lahiri ◽  
Oscar E Liburd
Keyword(s):  
Short Range ◽  
Field Studies ◽  
Fragaria X Ananassa ◽  
Delay Management ◽  
Crop Fields ◽  
Management Actions ◽  
Rate Of Spread ◽  
Central Plant ◽  
Scirtothrips Dorsalis ◽  
Leaf Tissues

Abstract Scirtothrips dorsalis Hood infest strawberry (Fragaria x ananassa Duchesne, Rosaceae) fields from nearby crop fields and surrounding vegetation and cause injury to plants by feeding on young leaf tissues. Greenhouse and field studies were conducted to determine the short-range movement of S. dorsalis to assess the risk of an early S. dorsalis population to spread to adjacent plants. In a greenhouse, 25 potted strawberry plants were arranged in two concentric rows around a central plant, where plants in inner rows were 20 cm, and those in the outer rows were 40 cm from the central plant. In the field, 20 strawberry plants were arranged in two beds (90 cm apart), ten in each bed, and five plants in each row, with plants 30 cm apart. White sticky cards were placed at 60–120 cm from the central plant. Fifty S. dorsalis adults were released on a centrally located plant, and the numbers of S. dorsalis adults and larvae and feeding injury were recorded for 9–17 d on adjacent plants and sticky cards. Results showed that significantly more S. dorsalis adults and larvae remained on the initially infested plant compared to adjacent plants, although few adults were found up to 120 cm on sticky cards. The rate of spread of feeding injury was low with slight bronzing injury (<10% injury) on adjacent plants by 14–17 d. Since most S. dorsalis remained on initially infested plants for at least 2 wk, it is feasible to delay management actions and ‘rescue’ plants around a plant with minor injury symptoms.

scholarly journals Avaliação da influência do uso e cobertura da terra na qualidade das águas superficiais da bacia hidrográfica do rio Pirapozinho (SP) (Evaluation of the effects of land use and occupation on superficial water quality of the hydrographic basin of the Pirapozinho river (SP))

2019 ◽  
Vol 12 (3) ◽  
pp. 738
Author(s):  
Bruno Magro Rodrigues ◽  
Lucas Prado Osco ◽  
Patricia Alexandra Antunes ◽  
Ana Paula Marques Ramos
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Sustainable Management ◽  
Hydrographic Basin ◽  
Crop Fields ◽  
Management Actions ◽  
Production Water ◽  
The Impact ◽  
Effects Of Land Use

A ocupação extensiva e, por vezes, indevida do solo pode resultar em uma série de problemas ambientais que aceleram a degradação de uma bacia hidrográfica, com consequências diretas na qualidade dos seus recursos hídricos. Esse trabalho avalia o impacto do uso e cobertura da terra em parâmetros quantitativos e de qualidade das águas superficiais da bacia hidrográfica do rio Pirapozinho. A produção cartográfica consistiu de mapa de uso e cobertura da terra, declividade, rede de drenagem, mapa de área de preservação permanente e mapa de Índice de Qualidade da Água (IQA). Tanto a coleta quanto as análises das águas superficiais da bacia foram desenvolvidas seguindo os procedimentos do Standard Methods. Os resultados das análises foram comparados com os valores de referência CONAMA, n° 357/05, alterada pela Resolução 410/2009 e pela 430/2011, sendo os padrões estabelecidos para rios de classe 2, mesma classe que se enquadra os corpos hídricos inseridos na bacia em estudo. Conclui-se que há um desequilíbrio ambiental na bacia do rio Pirapozinho. O mapa de uso e cobertura aponta que aproximadamente 90% da área da bacia encontra-se ocupada por pastagem e culturas. Outro aspecto é que mais de 84% da área de preservação permanente encontra-se desprovida de vegetação arbórea. Embora o mapa do IQA revele que a água da bacia possa ser classificada como boa (IQA entre 52 e 79) predominantemente, as análises laboratoriais apontam que há pontos na área com contaminação. Isto pode ser atribuído a atividades industriais e agropastoris desenvolvidas na bacia em estudo. Recomenda-se ações de manejo sustentável na bacia do rio Pirapozinho para a recuperação dos seus recursos naturais. A B S T R A C TExtensive and unduly occupation of soil may result in several environmental problems those contribute to accelerate the degradation of a hydrographic basin bringing diretly consequences to quality of its water resources. This paper evaluates the impact of land use and occupation on quantitative parameters and of superficial waters quality of the hydrographic basin of the Pirapozinho river. The cartographic products designed consisted of land use and occupation map, declivitity map, drainage network map, permanent preservation area map and map of Water Quality Index (WQI) of hydrographic basin. Both collection and analysis of the superficial waters samples were developed following the Standard Method procedure. The results of the laboratorial analyses were compared with the reference values at CONAMA 357/05 and 430/11 resolutions. We conclude that there is an environmental disequilibrium at the hydrographic basin of the Pirapozinho river. The land use and occupation map shows that approximately 90% of the area of the basin is occupied by pasture and crop fields. Other finding is that there is no arboreal vegetation in 84% of the permanent preservation area of the hydrographic basin. Although the WQI map revels that water of the basin can be classified as good (WQI among 52 and 79) predominately, the laboratorial analyses point out taht there is some points in area with contamination of water. This may be related to the industrial and agricultural activities performed in the area. We recommend sustainable management actions in the Pirapozinho river basin to recovery of its natural resources.Keywords: Cartographic production; water quality; environmental analysis; hydrographic basin.

scholarly journals Linking Ecology, Morphology, and Behavior to Conservation: Lessons Learned from Studies of Sea Turtles

2020 ◽  
Vol 60 (2) ◽  
pp. 440-455 ◽  
Author(s):  
Jeanette Wyneken ◽  
Michael Salmon
Keyword(s):  
Field Studies ◽  
Lessons Learned ◽  
Conservation Policies ◽  
Management Actions ◽  
Basic Understanding ◽  
And Performance ◽  
Basic Studies ◽  
And Behavior ◽  
Management And Conservation ◽  
Shape Changes

Synopsis Here we describe examples of studies that have contributed both to a basic understanding of the biology of imperiled marine turtles, and to their management and conservation. Key elements include, first and foremost, correctly identifying species that differ strikingly in their morphology at different life stages because with growth, they change size by several orders of magnitude and have accompanying shape changes. We also review comprehensive field studies documenting the need for management actions to correct abnormal shifts in sex ratios caused by climate change. We highlight the need to describe those perturbations in terms that are clear to regulators and personnel responsible for management and conservation policies. Finally, we review several basic studies that enhance our understanding of how selection has shaped morphological, functional, and performance attributes, and describe how that knowledge can be applied to the tasks required for enhancing species recovery.

scholarly journals Shrubland fire behaviour modelling with microplot data

2000 ◽  
Vol 30 (6) ◽  
pp. 889-899 ◽  
Author(s):  
Paulo M Fernandes ◽  
Wendy R Catchpole ◽  
Francisco C Rego
Keyword(s):  
Wind Speed ◽  
Field Studies ◽  
Fire Spread ◽  
Flame Length ◽  
Fire Behaviour ◽  
Fire Propagation ◽  
Average Value ◽  
Behaviour Modelling ◽  
Rate Of Spread ◽  
Behaviour Models

Fire behaviour modelling has been based primarily on experiments involving the measurement of a certain number of fires, where each variable is represented by an average value per fire. The main objective of this study was to examine if data collected from a microplot sampling design could be used to derive meaningful fire behaviour models. Three burns were conducted in low shrubland of Erica umbellata Loefl., and Chamaespartium tridentatum (L.) P. Gibbs in northeastern Portugal. Wind speed and aerial dead fuel moisture content varied from 5 to 27 km/h and from 14 to 21%, respectively. Rate of spread and flame length ranged from 0.3 to 14.1 m/min and from 0.2 to 3.1 m, respectively. Rate of fire spread could be described effectively in terms of an empirical model with wind speed and fuel height as independent variables. The coefficients that describe the effects of wind speed and fuel height on fire propagation were consistent with published values for similar fuel types. Flame length was strongly related to Byram's fireline intensity. Microplot sampling is not free from methodological problems, which are discussed, but can be effectively used in field studies of fire behaviour.

Some Effects of Oxidant Air Pollutants (Ozone and Peroxyacetyl Nitrate) on the Ultrastructure of Leaf Tissues

1972 ◽  
Vol 30 ◽  
pp. 360-361
Author(s):  
William W. Thomson ◽  
Elizabeth S. Swanson
Keyword(s):  
Air Pollutants ◽  
Electron Microscopic Examination ◽  
Peroxyacetyl Nitrate ◽  
Electron Microscopic ◽  
Growth Physiology ◽  
Physiology And Biochemistry ◽  
Entire Plant ◽  
Leaf Tissues ◽  
Gaseous Hydrocarbons ◽  
The Individual

The oxidant air pollutants, ozone and peroxyacetyl nitrate, are produced in the atmosphere through the interaction of light with nitrogen oxides and gaseous hydrocarbons. These oxidants are phytotoxicants and are known to deleteriously affect plant growth, physiology, and biochemistry. In many instances they induce changes which lead to the death of cells, tissues, organs, and frequently the entire plant. The most obvious damage and biochemical changes are generally observed with leaves.Electron microscopic examination of leaves from bean (Phaseolus vulgaris L.) tobacco (Nicotiana tabacum L.) and cotton (Gossipyum hirsutum L.) fumigated for .5 to 2 hours with 0.3 -1 ppm of the individual oxidants revealed that changes in the ultrastructure of the cells occurred in a sequential fashion with time following the fumigation period. Although occasional cells showed severe damage immediately after fumigation, the most obvious change was an enhanced clarity of the cell membranes.

Domain coarsening by grain boundary migration in ordered Ni4Mo

1986 ◽  
Vol 44 ◽  
pp. 560-561
Author(s):  
K. Vasudevan ◽  
H. P. Kao ◽  
C. R. Brooks ◽  
E. E. Stansbury
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Short Range ◽  
Boundary Migration ◽  
Grain Boundary Migration ◽  
Rapid Cooling ◽  
Temperature Range ◽  
Fee Structure ◽  
Domain Coarsening ◽  
Boundary Reaction

The Ni4Mo alloy has a short-range ordered fee structure (α) above 868°C, but transforms below this temperature to an ordered bet structure (β) by rearrangement of atoms on the fee lattice. The disordered α, retained by rapid cooling, can be ordered by appropriate aging below 868°C. Initially, very fine β domains in six different but crystallographically related variants form and grow in size on further aging. However, in the temperature range 600-775°C, a coarsening reaction begins at the former α grain boundaries and the alloy also coarsens by this mechanism. The purpose of this paper is to report on TEM observations showing the characteristics of this grain boundary reaction.

Ordering in Ni4Mo by TEM and APFIM

1987 ◽  
Vol 45 ◽  
pp. 214-215
Author(s):  
E.A. Kenik ◽  
T.A. Zagula ◽  
M.K. Miller ◽  
J. Bentley
Keyword(s):  
Electron Irradiation ◽  
Low Temperatures ◽  
Short Range ◽  
Atom Probe ◽  
Range Order ◽  
Considerable Time ◽  
Probe Field ◽  
Disordered Phase ◽  
Transmission Electron ◽  
Diffraction Patterns

The state of long-range order (LRO) and short-range order (SRO) in Ni4Mo has been a topic of interest for a considerable time (see Brooks et al.). The SRO is often referred to as 1½0 order from the apparent position of the diffuse maxima in diffraction patterns, which differs from the positions of the LRO (D1a) structure. Various studies have shown that a fully disordered state cannot be retained by quenching, as the atomic arrangements responsible for the 1½0 maxima are present at temperatures above the critical ordering temperature for LRO. Over 20 studies have attempted to identify the atomic arrangements associated with this state of order. A variety of models have been proposed, but no consensus has been reached. It has also been shown that 1 MeV electron irradiation at low temperatures (∼100 K) can produce the disordered phase in Ni4Mo. Transmission electron microscopy (TEM), atom probe field ion microscopy (APFIM), and electron irradiation disordering have been applied in the current study to further the understanding of the ordering processes in Ni4Mo.

Portein-gold labelling of ultrathin sections of wheat spot mosaic-affected wheat plants

1990 ◽  
Vol 48 (3) ◽  
pp. 680-681
Author(s):  
K. S. Zaychuk ◽  
M. H. Chen ◽  
C. Hiruki
Keyword(s):  
Osmium Tetroxide ◽  
Rnase A ◽  
Leaf Ultrastructure ◽  
Double Membrane ◽  
Young Root ◽  
Leaf Tissues ◽  
Membrane Bound ◽  
Ultrathin Sections ◽  
Gold Labelling ◽  
Electron Dense Core

Wheat spot mosaic (WSpM), which frequently occurs with wheat streak mosaic virus was first reported in 1956 from Alberta. Singly isolated, WSpM causes chlorotic spots, chlorosis, stunting, and sometimes death of the wheat plants. The vector responsible for transmission is the eriophyid mite, Eriophyes tulipae Kiefer. The examination of leaf ultrastructure by electron microscopy has revealed double membrane bound bodies (DMBB’s) 0.1-0.2 μm in diameter. Dispersed fibrils within these bodies suggested the presence of nucleic acid. However, neither ribosomes characteristic of bacteria, mycoplasma and the psittacosis group of organisms nor an electron dense core characteristic of many viruses was commonly evident.In an attempt to determine if the DMBB’s contain nucleic acids, RNase A, DNase I, and lactoferrin protein were conjugated with 10 nm colloidal gold as previously described. Young root and leaf tissues from WSpM-affected wheat plants were fixed in glutaraldehyde, postfixed in osmium tetroxide,and embedded in Spurr’s resin.

Mesophyll conductance: the leaf corridors for photosynthesis

2020 ◽  
Vol 48 (2) ◽  
pp. 429-439 ◽  
Author(s):  
Jorge Gago ◽  
Danilo M. Daloso ◽  
Marc Carriquí ◽  
Miquel Nadal ◽  
Melanie Morales ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Main Role ◽  
Mesophyll Conductance ◽  
Future Studies ◽  
Cell Structures ◽  
Leaf Tissues ◽  
Change Framework ◽  
Chloroplast Stroma

Besides stomata, the photosynthetic CO2 pathway also involves the transport of CO2 from the sub-stomatal air spaces inside to the carboxylation sites in the chloroplast stroma, where Rubisco is located. This pathway is far to be a simple and direct way, formed by series of consecutive barriers that the CO2 should cross to be finally assimilated in photosynthesis, known as the mesophyll conductance (gm). Therefore, the gm reflects the pathway through different air, water and biophysical barriers within the leaf tissues and cell structures. Currently, it is known that gm can impose the same level of limitation (or even higher depending of the conditions) to photosynthesis than the wider known stomata or biochemistry. In this mini-review, we are focused on each of the gm determinants to summarize the current knowledge on the mechanisms driving gm from anatomical to metabolic and biochemical perspectives. Special attention deserve the latest studies demonstrating the importance of the molecular mechanisms driving anatomical traits as cell wall and the chloroplast surface exposed to the mesophyll airspaces (Sc/S) that significantly constrain gm. However, even considering these recent discoveries, still is poorly understood the mechanisms about signaling pathways linking the environment a/biotic stressors with gm responses. Thus, considering the main role of gm as a major driver of the CO2 availability at the carboxylation sites, future studies into these aspects will help us to understand photosynthesis responses in a global change framework.

Early Education in Short-Range Historical Perspective

1969 ◽  
Vol 14 (8) ◽  
pp. 437-438
Author(s):  
CELIA STENDLER LAVATELLI
Keyword(s):  
Short Range ◽  
Historical Perspective ◽  
Early Education
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