Flaming to Reduce Inocula of the Boxwood Blight Pathogen, Cylindrocladium pseudonaviculatum, in Field Soil

2012 ◽  
Vol 13 (1) ◽  
pp. 33 ◽  
Author(s):  
Norman L. Dart ◽  
Sarah M. Arrington ◽  
Sarah M. Weeda
Keyword(s):  
Significant Role ◽  
Plant Tissue ◽  
Field Soil ◽  
Infested Plant ◽  
Infested Field

Infested plant tissue can play a significant role in the epidemiology of boxwood blight in ornamental nursery systems. In an effort to reduce inoculum levels in an infested field in Carroll Co., Virginia, symptomatic plants were removed, collected into a pile, and destroyed by burning using a propane push flamer. The authors investigated whether soil flaming would be effective to reduce viable inocula of C. pseudonaviculatum in the upper layer of soil. Accepted for publication 4 October 2012. Published 26 October 2012.

scholarly journals CRISPR-Based Isothermal Next-Generation Diagnostic Method for Virus Detection in Sugarbeet

2021 ◽  
Vol 12 ◽  
Author(s):  
Vanitharani Ramachandran ◽  
John J. Weiland ◽  
Melvin D. Bolton
Keyword(s):  
Virus Detection ◽  
Detection Methods ◽  
Target Sequence ◽  
Field Soil ◽  
Human Virus ◽  
Guide Rna ◽  
Highly Sensitive ◽  
Infested Field ◽  
Virus Diagnostics

Rhizomania is a disease of sugarbeet caused by beet necrotic yellow vein virus (BNYVV) that significantly affects sugarbeet yield globally. Accurate and sensitive detection methods for BNYVV in plants and field soil are necessary for growers to make informed decisions on variety selection to manage this disease. A recently developed CRISPR-Cas-based detection method has proven highly sensitive and accurate in human virus diagnostics. Here, we report the development of a CRISPR-Cas12a-based method for detecting BNYVV in the roots of sugarbeet. A critical aspect of this technique is the identification of conditions for isothermal amplification of viral fragments. Toward this end, we have developed a reverse transcription (RT) recombinase polymerase amplification (RPA) for detecting BNYVV in sugarbeet roots. The RT-RPA product was visualized, and its sequence was confirmed. Subsequently, we designed and validated the cutting efficiency of guide RNA targeting BNYVV via in vitro activity assay in the presence of Cas12a. The sensitivity of CRISPR-Cas12a trans reporter-based detection for BNYVV was determined using a serially diluted synthetic BNYVV target sequence. Further, we have validated the developed CRISPR-Cas12a assay for detecting BNYVV in the root-tissue of sugarbeet bait plants reared in BNYVV-infested field soil. The results revealed that BNYVV detection is highly sensitive and specific to the infected roots relative to healthy control roots as measured quantitatively through the reporter signal. To our knowledge, this is the first report establishing isothermal RT-RPA- and CRISPR-based methods for virus diagnostic approaches for detecting BNYVV from rhizomania diseased sugarbeet roots.

Estimating numbers.

2021 ◽  
pp. 42-59
Author(s):  
Johannes Hallmann ◽  
Matthias Daub ◽  
Wim Wesemael
Keyword(s):  
Plant Tissue ◽  
Field Soil ◽  
Egg Masses ◽  
Gall Index

Abstract Estimating nematode numbers is required to quantify the presence of certain nematode taxa in plant tissue, field soil or any other substrates. This chapter describes the enumeration of nematodes within plant tissue (e.g. roots, stems, leaves, seeds) and in liquids. It also deals with estimating numbers of cysts; eggs and juveniles isolated from cysts; gall index; and egg masses.

scholarly journals Response of cucurbit species to Rotylenchulus reniformis

2005 ◽  
Vol 30 (1) ◽  
pp. 85-87 ◽  
Author(s):  
Gustavo R. C. Torres ◽  
Elvira M. R. Pedrosa ◽  
Kércya M. S. Siqueira ◽  
Romero M. Moura
Keyword(s):  
Cucumis Melo ◽  
Citrullus Lanatus ◽  
Control Measures ◽  
Effective Control ◽  
Field Soil ◽  
Rotylenchulus Reniformis ◽  
Nematode Reproduction ◽  
Infested Field ◽  
High Reduction ◽  
Shoot Mass

The state of Rio Grande do Norte is the major melon (Cucumis melo) producer in Brazil and the reniform nematode Rotylenchulus reniformis has become increasingly important due to damages to that crop and the lack of resistant cultivars and effective control measures. Under these circumstances, eight cucurbit genotypes were screened for resistance or tolerance to a population of R. reniformis in naturally infested field soil, under greenhouse conditions. A high reduction in shoot mass was found in all infected genotypes. Watermelon (Citrullus lanatus) cv. Sugar Baby showed the lowest rate of nematode reproduction.

Detection of Cercospora beticola by PCR in amended and naturally infested field soil.

2007 ◽  
Author(s):  
Robert E. Lartey ◽  
TehCan Caesar-TonThat ◽  
Sophia Hanson ◽  
William M. Iversen ◽  
Robert G. Evans
Keyword(s):  
Cercospora Beticola ◽  
Field Soil ◽  
Infested Field

A pythium root rot of muskmelon

1968 ◽  
Vol 46 (10) ◽  
pp. 1165-1171 ◽  
Author(s):  
C. D. McKeen ◽  
H. J. Thorpe
Keyword(s):  
Experimental Data ◽  
Root Rot ◽  
Pythium Ultimum ◽  
Wilt Disease ◽  
Field Soil ◽  
Southern Ontario ◽  
Pythium Root Rot ◽  
High Soil ◽  
Infested Field ◽  
Soil Temperatures

Pythium ultimum was readily isolated from the necrotic roots of young and mature muskmelon plants growing in soil in which root rot had been severe. Muskmelons planted in steamed soils inoculated with P. ultimum developed necrotic roots and aboveground symptoms closely similar to those produced in naturally infested field soil. The fungus was considerably more pathogenic at low than at high soil temperatures. All of seven commercial varieties of muskmelon commonly grown in southern Ontario were moderately to highly susceptible to P. ultimum. Experimental data support the conclusion that P. ultimum probably plays an important role in the "sudden wilt" disease of mature muskmelon plants.

scholarly journals Detection of Soilborne Alternaria radicina and Its Occurrence in California Carrot Fields

Plant Disease ◽  
1998 ◽  
Vol 82 (8) ◽  
pp. 891-895 ◽  
Author(s):  
B. M. Pryor ◽  
R. M. Davis ◽  
R. L. Gilbertson
Keyword(s):  
Selective Medium ◽  
Causal Agent ◽  
Black Rot ◽  
Field Soil ◽  
Positive Correlation ◽  
Organic Debris ◽  
Selective Agar ◽  
Infested Field ◽  
Dry Soil ◽  
Rot Disease

Alternaria radicina, causal agent of black rot disease of carrot, was recovered from soil by plating dilutions on a semi-selective medium, A. radicina semi-selective agar. The efficiency of this soil assay was 93% based on recovery of the fungus from non-infested field soil amended with A. radicina conidia. Soilborne A. radicina was recovered from five of six carrot-growing areas in California, but was only commonly found in the Cuyama Valley, where the fungus was detected in 83% of sampled fields. Over a 3-year period of sampling, A. radicina soil populations in Cuyama Valley fields prior to carrot planting ranged from 0 to 317 CFU/g. There was a positive correlation between A. radicina soil populations in these fields and the incidence of black rot disease at harvest. A. radicina was recovered from dry soil after 4 years of storage, and the fungus survived in this soil as solitary conidia or as conidia associated with organic debris.

Plant-parasitic nematodes in soil-less culture systems

Nematology ◽  
2005 ◽  
Vol 7 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Johannes Hallmann ◽  
Detlef Hänisch ◽  
Jörg Braunsmann ◽  
Michael Klenner
Keyword(s):  
Plant Material ◽  
Short Paper ◽  
Parasitic Nematodes ◽  
Primary Reason ◽  
Field Soil ◽  
Plant Parasitic Nematodes ◽  
Infested Plant ◽  
Culture Systems ◽  
Plant Parasitic

Abstract The development from growing plants in field soil to soil-less culture systems has not resulted in the elimination of problems caused by plant-parasitic nematodes. Species of Meloidogyne and Radopholus have been reported to occur in soil-less culture systems, such as flower crops. The reasons for initial nematode infestation are numerous but the primary reason is likely to be infested plant material. Since nematodes are not expected in soil-less systems, they are often overlooked. However, extension specialists report an increasing occurrence of plant-parasitic nematodes in soil-less culture systems and nematodes seem to be more prevalent than is often thought likely. In an attempt to increase the awareness of the prevalence of plant-parasitic nematodes in soil-less culture systems, this short paper summarises incidences of nematode detections and reviews methods for their detection and strategies for their control.

scholarly journals Management of Diseases Induced by Soil- Borne Pathogens, Solarization and Biological Control

1998 ◽  
Vol 3 (1) ◽  
pp. 65
Author(s):  
C. Alabouvette
Keyword(s):  
Biological Control ◽  
Population Density ◽  
Plant Pathogens ◽  
Field Soil ◽  
Environment Friendly ◽  
Soil Borne Pathogens ◽  
Beneficial Microorganisms ◽  
Antagonistic Microorganisms ◽  
Infested Field ◽  
Selection Of

Diseases induced by soil-borne plant pathogens are among the most difficult to control. Prophylactic methods aiming at preventing the introduction of pathogens in healthy soils have to be respected, because it is almost impossible to eradicate pathogens from an infested field soil. Even the drastic disinfestation techniques based on the application of biocide molecules such as methylbromide failed to eliminate the pathogens, but are harmful to man and the environment. Growers should prefer new, environment friendly techniques such as solarization and biological disinfestation of soils. These methods induce changes in the microbial balance, reducing the population density of the pathogens and stimulating the activity of some beneficial microorganisms. The study of soils that naturally suppress diseases induced by soil-borne pathogens has led to a better understanding of the interactions between pathogenic and antagonistic microorganisms and has resulted in the selection of bio control agents.

Effects of Host Age on Development of Cavity Spot Disease of Carrots Caused by Pythium coloratum in Western Australia Khaled

1997 ◽  
Vol 45 (4) ◽  
pp. 727 ◽  
Author(s):  
A. El-Tarabily ◽  
Giles E. St J. Hardy ◽  
Krishnapillai Sivasithamparam
Keyword(s):  
Western Australia ◽  
Infested Soil ◽  
Host Age ◽  
Field Soil ◽  
Spot Disease ◽  
Cavity Spot ◽  
Infested Field ◽  
Time Of Infection ◽  
Pythium Coloratum ◽  
Time Of Harvest

Three experiments were conducted with Pythium coloratum Vaartaja, a causal agent of cavity spot disease of carrots in Western Australia, to study the relationships between host age, time of infection and development of cavity spot lesions. Pythium coloratum was isolated frequently from 3-6-week-old asymptomatic roots of carrots grown in soils infested naturally or artificially with the pathogen. Carrots grown in containers of soil artificially infested with P. coloratum, but not those in naturally infested field soil, developed cavity spot lesions after 6 weeks. Early infection of carrot seedlings at or before 3 weeks by P. coloratum in artificially infested soils followed by their transfer to pathogen-free soil was sufficient to cause cavity spot disease at the time of harvest (16 weeks). The disease levels in this treatment were not different from those transferred to P. coloratum-infested soil. There was no significant (P > 0.05) association between carrot age and the ability of P. coloratum to infect the roots and to cause cavity spot lesions at harvest.

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