scholarly journals Spilocaea oleagina in Olive Groves of Southern Spain: Survival, Inoculum Production, and Dispersal

Plant Disease ◽  
2013 ◽  
Vol 97 (12) ◽  
pp. 1549-1556 ◽  
Author(s):  
J. R. Viruega ◽  
J. Moral ◽  
L. F. Roca ◽  
N. Navarro ◽  
A. Trapero
Keyword(s):  
Control Strategies ◽  
Exponential Model ◽  
Tree Canopy ◽  
Southern Spain ◽  
Limited Information ◽  
Spore Trap ◽  
Disease Epidemiology ◽  
Inoculum Production ◽  
Pathogen Survival ◽  
Fallen Leaves

Olive scab caused by the mitosporic fungus Spilocaea oleagina is the most important foliar disease of olive. Limited information is available on pathogen survival and disease epidemiology; however, this information is essential for development of new control strategies. Pathogen survival and inoculum production on infected olive leaves and conidial dispersal were evaluated during 4 years in an olive orchard of the susceptible ‘Picual’ in southern Spain. Infected leaves in the tree canopy were important for pathogen survival and conidia production. The number of conidia per square centimeter of scab lesion and their viability varied greatly throughout the seasons and between years; conidial density in lesions was highest (about 1 to 5 × 105 conidia cm–2) from November to February in favorable years. Conidial density declined sharply in other periods of the year (becoming zero in summer) or in less favorable years. The pathogen did not form new conidia in scab lesions, although some pseudothecia-like structures and chlamydospores were detected on fallen leaves. Under humid conditions, the pathogen could not be detected on fallen leaves after 3 months because the leaves were colonized by saprophytic fungi. The dispersal of conidia as a function of distance from infected leaves in the tree canopy was well described by an exponential model which, together with the lack of conidia in a Burkard spore trap, showed that conidia were mainly rain-splash dispersed. Some trapped conidia were attached to olive leaf trichomes, suggesting that detached trichomes might enhance wind dispersal of conidia.

Microfungal succession on living leaves of Populus tremuloides

1979 ◽  
Vol 57 (24) ◽  
pp. 2800-2811 ◽  
Author(s):  
H. G. Wildman ◽  
D. Parkinson
Keyword(s):  
Populus Tremuloides ◽  
Aureobasidium Pullulans ◽  
Hyphal Growth ◽  
Limited Range ◽  
Tree Canopy ◽  
Fungal Colonization ◽  
Phylloplane Fungi ◽  
Sampling Height ◽  
Fallen Leaves ◽  
Poplar Leaves

The microfungal succession on the surfaces and interior of attached aspen poplar leaves was followed throughout a growing season at three heights in the tree canopy using a number of isolation and observational techniques. The fungal succession on and within the leaves was in general similar to that reported for other angiosperm leaves. The outer sheathing bud scales were colonized by a limited range of fungi, but the enclosed leaves were free from fungal colonization. The adaxial surfaces of young newly expanded leaves were sparsely colonized by fungi. As the leaves matured they were extensively colonized by the common phylloplane fungi (pink and white yeasts, Aureobasidium pullulans, Cladosporium spp., Alternaria alternata, and Epicoccum purpurascens) especially on the adaxial surface. At senescence both leaf surfaces had extensive hyphal growth on them and a greater internal colonization by phylloplane fungi had occurred. Common phylloplane fungi were less frequently isolated from freshly fallen leaves than from the senescent leaves, but a sterile dark species was frequently isolated from within them. The height of the leaves in the canopy was shown to influence the mycoflora of the aspen poplar leaves, with certain species (the yeasts, Aureobasidium pullulans, Cladosporium spp., and Botrytis cinerea) showing changes in their frequency with sampling height.

scholarly journals Research on Invasive Nontyphoidal Salmonella Disease and Developments Towards Better Understanding of Epidemiology, Management, and Control Strategies

2020 ◽  
Vol 71 (Supplement_2) ◽  
pp. S127-S129
Author(s):  
Samuel Kariuki ◽  
Ellis Owusu-Dabo
Keyword(s):  
Burden Of Illness ◽  
Control Strategies ◽  
Sub Saharan Africa ◽  
Disease Entity ◽  
Middle Income ◽  
Diagnostic Strategies ◽  
Disease Epidemiology ◽  
Middle Income Countries ◽  
Sub Saharan ◽  
And Control

Abstract During the 11th International Conference on Typhoid and Other Invasive Salmonelloses held in Hanoi, Vietnam, a number of papers were presented on the burden of disease, epidemiology, genomics, management, and control strategies for invasive nontyphoidal Salmonella (iNTS) disease, which is increasingly becoming an important public health threat in low- and middle-income countries, but especially in sub-Saharan Africa (sSA). Although there were minor variations in characteristics of iNTS in different settings (urban vs rural, country to country), it was observed that iNTS has gained greater recognition as a major disease entity in children younger than 5 years. Renewed efforts towards greater understanding of the burden of illness, detection and diagnostic strategies, and management and control of the disease in communities in sSA through the introduction of vaccines will be important.

scholarly journals Lethal Cankers Caused by Phytophthora spp. in Almond Scions: Specific Etiology and Potential Inoculum Sources

Plant Disease ◽  
1999 ◽  
Vol 83 (8) ◽  
pp. 739-745 ◽  
Author(s):  
G. T. Browne ◽  
M. A. Viveros
Keyword(s):  
Control Strategies ◽  
Soil Surface ◽  
Crown Rot ◽  
Inoculum Sources ◽  
Disease Epidemiology ◽  
Phytophthora Spp ◽  
Almond Trees ◽  
Root And Crown Rot ◽  
Pathogenicity Tests ◽  
Significant Disease

Etiology of a new lethal canker syndrome of almond trees was investigated in the San Joaquin Valley of California. Phytophthora citricola was isolated most frequently from cankers limited to the aboveground scion portions of trees; whereas P. cactorum usually was isolated from cankers originating at or below the soil surface. Repeated observations and isolations indicated that some of the cankers associated with each species were perennial. In pathogenicity tests, isolates of P. cactorum and P. citricola caused bark cankers in excised segments of almond shoots and branches, as well as root and crown rot on potted almond seedlings. Only P. citricola caused significant disease in root and crown tissues of peach seedlings. When pear fruits and almond seedlings were used as bait, P. cactorum and P. citricola were isolated from orchard soil, debris collected in natural depressions where scaffold branches and the tree trunk joined at a common point, and debris deposited on tree surfaces during nut harvest. Control strategies for Phytophthora diseases of almond should consider aboveground as well as belowground modes of attack by P. citricola and P. cactorum. Debris infested with these pathogens and deposited on trees during harvest may play a role in the disease epidemiology.

scholarly journals Survival of Xiphinema index in Vineyard Soil and Retention of Grapevine fanleaf virus Over Extended Time in the Absence of Host Plants

2005 ◽  
Vol 95 (10) ◽  
pp. 1151-1156 ◽  
Author(s):  
Gérard Demangeat ◽  
Roger Voisin ◽  
Jean-Claude Minot ◽  
Nathalie Bosselut ◽  
Marc Fuchs ◽  
...  
Keyword(s):  
Host Plants ◽  
Control Strategies ◽  
Limited Information ◽  
Grapevine Fanleaf Virus ◽  
Term Survival ◽  
Adverse Conditions ◽  
Xiphinema Index ◽  
Vineyard Soil ◽  
Viral Genomic Rna

Grapevine fanleaf virus (GFLV) is transmitted specifically from grapevine to grapevine by the ectoparasitic root-feeding nematode Xiphinema index. Limited information is available on the survival of X. index in vineyard soil and on the retention of GFLV by X. index over extended periods of time. We addressed these two issues by quantifying the numbers of living X. index recovered from soil samples that were collected in three naturally GFLV-infected vineyards in France and subsequently stored at 7 or 20°C in the absence of host plants. Our data indicated a two- to eightfold decrease in X. index numbers but the recovery of 8 to 10 living fourth-stage juveniles (J4) and adults per kilogram of soil after 4 years of storage regardless of temperature. In addition, GFLV was detected readily in all groups of 20 isolated X. index adults and J4 (except for J4 that were kept 4 years at 20°C) by reverse transcription-polymerase chain reaction using total nematode RNAs and a primer set located in conserved regions at the 3′ end of viral genomic RNA 2. Our findings on the long-term survival of viruliferous X. index under adverse conditions emphasize the need for new control strategies against GFLV.

scholarly journals Impact of Planting Dates and Climatic Factors on the Incidence and Severity of Sorghum Grain Mold in Morelos, Mexico

Plant Disease ◽  
2003 ◽  
Vol 87 (9) ◽  
pp. 1139-1143 ◽  
Author(s):  
R. Montes-Belmont ◽  
I. Méndez-Ramírez ◽  
H. E. Flores-Moctezuma ◽  
R. A. Nava-Juárez
Keyword(s):  
Relative Humidity ◽  
Climatic Factors ◽  
Control Strategies ◽  
Disease Incidence ◽  
Limited Information ◽  
Planting Dates ◽  
Terminal Drought ◽  
Field Samples ◽  
Grain Mold ◽  
Sorghum Grain

It is difficult to develop control strategies for grain mold of sorghum because of the limited information on the epidemiology of grain mold in Mexico. The objectives of this study were to identify the fungi associated with grain mold in Morelos, Mexico, and to explore the relationship among planting dates, disease development, and relative humidity and temperature. Fusarium thapsinum was isolated from 97% of the grains from field samples of infested sorghum grains in Morelos, Mexico. The influence of planting dates on the development of sorghum grain mold was determined at Tlayca, Morelos, Mexico, during the rainy seasons of 1998, 1999, and 2000. Incidence of grain mold varied annually, but disease incidence and severity were highest in 1998. Planting dates from 1 June to 13 July had the highest incidence of grain mold during the 3 years. Throughout the study, disease severity was generally low, and yield was not affected. The late planting dates in 1999 and 2000 had reduced yields due to terminal drought of the crop. Increase of disease was predicted by mean temperature, but not by mean relative humidity.

scholarly journals Cattle Tail Lice

EDIS ◽  
2006 ◽  
Vol 2006 (8) ◽  
Author(s):  
Phillip E. Kaufman ◽  
Philip G. Koehler ◽  
Jerry F. Butler
Keyword(s):  
United States ◽  
Control Strategies ◽  
The United States ◽  
Publication Date ◽  
Original Publication ◽  
Limited Information ◽  
Major Pest

The cattle tail louse, Haematopinus quadripertusus (Figure 1), is the most important damaging cattle louse in Florida. In other parts of the United States the short-nosed cattle louse is the major pest. While much information is available for the control of short-nosed cattle lice, only limited information is available specifically on control of the tail louse. Important differences in the biology of these two species require differing control strategies. This document is ENY-271, one of a series of the Department of Entomology and Nematology, UF/IFAS Extension. Original publication date May 1995. Revised December 2005. ENY-271/IG127: Cattle Tail Lice (ufl.edu)

scholarly journals May arsenic pollution contribute to limiting Artemia franciscana invasion in southern Spain?

2015 ◽  
Author(s):  
Marta I Sánchez ◽  
Cathleen Petit ◽  
Mónica Martínez-Haro ◽  
Mark A Taggart ◽  
Andy J Green
Keyword(s):  
Climate Change ◽  
Natural Populations ◽  
Climate Scenario ◽  
Artemia Franciscana ◽  
Southern Spain ◽  
Limited Information ◽  
Complex Interactions ◽  
Ecological Implications ◽  
Survival And Growth ◽  
As Stress

Limited information exists regarding complex interactions between biological invasions, pollution, and climate change. Most studies indicate that pollution tends to favor invasive species. Here, we provide evidence that arsenic (As) pollution may contribute to limit the invasion of the exotic brine shrimp Artemia franciscana. We tested As toxicity in natural populations of Artemia parthenogenetica (native) and A. franciscana from high and low As contaminated environments in southern Spain, under current temperature conditions and as per a future climate scenario (i.e., an increase of 4ºC). Acute toxicity was estimated on the basis of the median lethal concentration (at 24h), and chronic toxicity (at 26 days) was evaluated by measuring Artemia survival and growth under sublethal exposures. At 25ºC native A. parthenogenetica from the highly polluted Odiel and Tinto estuary was much more resistant to acute As stress (LC50-24h, 24.67 mg L-1) than A. franciscana (15.78 mg L-1) and A. parthenogenetica populations from unpolluted sites (12.04 mg L-1) - suggesting that local adaptation to polluted conditions may occur. At 29ºC, resistance of A. parthenogenetica from Odiel decreased significantly, and there were no statistical differences in sensitivity between the three species/populations, suggesting that climate change may enhance the probability of invasion. Resistance increased with developmental stage from nauplii to adults, and was extremely high in cysts which still hatched at As concentrations of up to 6400mg L-1. Under sublethal chronic exposure A. franciscana performed better (survival and growth) than A. parthenogenetica, and both species experienced a faster growth when exposed, compared with unexposed (control) individuals, probably due to the hormesis. We discuss the ecological implications of our results.

scholarly journals Geographical Distribution of Biomphalaria pfeifferi snails in East Africa

2021 ◽  
Author(s):  
Victor Onyango Magero ◽  
Sammy Kisara ◽  
Chris Wade
Keyword(s):  
East Africa ◽  
Geographical Distribution ◽  
Lake Victoria ◽  
Control Strategies ◽  
Limited Information ◽  
Irrigation Canals ◽  
Lake Victoria Basin ◽  
Irrigation Scheme ◽  
Biomphalaria Pfeifferi ◽  
And Control

There is limited information on the distribution of B. pfeifferi, an important snail intermediate host of schistosomiasis, in East Africa. This study assessed the incidence and geographical distribution of B. pfeifferi snails in Kenya, Uganda and Tanzania. Maximum Entropy modeling was used to predict the potential distribution of B. pfeifferi snails, in line with habitat suitability. Malacological surveys were then conducted guided by MaxEnt predictions and information obtained from previous research papers. The surveys were conducted at a total of 156 sites including streams, rivers, lake shores, dams and irrigation canals over a 3 year period (2018 to 2020). Geographical coordinates, ecological and physicochemical information was recorded for the sites visited. Snails were identified morphologically, based on shell characters using established identification keys. B. pfeifferi snails were found at 23.07% (36/156) of the sites sampled. Streams proved to be the habitats most preferred by B. pfeifferi snails (50% of all of the sites where the snails were found were streams), followed by rivers (20.6%), irrigation canals (8.8%), lake shores (8.8%), springs (5.9%), and dams (5.9%) with snail abundance increasing with increase in temperature and decrease in water depth. B. pfeifferi was found in the Lake Victoria basin, Mwea Irrigation Scheme and Eastern Province of Kenya, the Lake Albert region, Lango region, Soroti district, Lower Moshi irrigation scheme, Babati district, Iringa region, Tabora region and Kigoma region. Information on the distribution of B. pfeifferi in East Africa will aid in developing prevention and control strategies for schistosomiasis.

Multirobot Control Strategies for Collective Transport

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Hamed Farivarnejad ◽  
Spring Berman
Keyword(s):  
Control Strategies ◽  
Autonomous Systems ◽  
Annual Review ◽  
Publication Date ◽  
Limited Information ◽  
Uncertain Environments ◽  
Multirobot Control ◽  
Collective Transport ◽  
Control Objective ◽  
Future Work

One potential application of multirobot systems is collective transport, a task in which multiple robots collaboratively move a payload that is too large or heavy for a single robot. In this review, we highlight a variety of control strategies for collective transport that have been developed over the past three decades. We characterize the problem scenarios that have been addressed in terms of the control objective, the robot platform and its interaction with the payload, and the robots’ capabilities and information about the payload and environment. We categorize the control strategies according to whether their sensing, computation, and communication functions are performed by a centralized supervisor or specialized robot or autonomously by the robots. We provide an overview of progress toward control strategies that can be implemented on robots with expanded autonomous functionality in uncertain environments using limited information, and we suggest directions for future work on developing such controllers. Expected final online publication date for the Annual Review of Control, Robotics, and Autonomous Systems, Volume 5 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Virulence Genes, Shiga Toxin Subtypes, Serogroups, and Clonal Relationship of Shiga Toxin-Producing Escherichia Coli Strains Isolated from Livestock and Companion Animals

Animals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 733 ◽  
Author(s):  
Nicolás Galarce ◽  
Beatriz Escobar ◽  
Fernando Sánchez ◽  
Esteban Paredes-Osses ◽  
Raúl Alegría-Morán ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Control Strategies ◽  
Companion Animals ◽  
Clonal Diversity ◽  
Severe Illness ◽  
Limited Information ◽  
And Control ◽  
Relationship Of

Shiga toxin-producing Escherichia coli (STEC) is a zoonotic pathogen that causes severe illness in humans and is an important cause of foodborne disease. In Chile, there is limited information on the virulence characteristics of this pathogen in livestock, and none in companion animals. The aim of this study was to characterize STEC strains isolated from cattle, swine, dogs, and cats, in Chile, in terms of the presence of Shiga toxin types and subtypes, virulence genes, serogroups, and clonality. One-thousand two-hundred samples were collected, isolating 54 strains (4.5%), where stx1a (68.5%) and ehxA (74.1%) were the most frequently detected virulence genes. Only one strain belonging to the most clinically relevant serogroups was identified. Pulsed field gel electrophoresis analysis showed high clonal diversity among strains isolated from cattle, while those from swine showed the same pattern. This study provides further evidence regarding cattle and swine in Chile as a potential source of a wide variety of STEC strains that could potentially cause severe illness in humans, and that companion animals do not seem to represent a relevant reservoir. It also argues that preventive and control strategies should not be focused on detecting serogroups, but instead, on detecting their determinants of virulence.

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