scholarly journals Determination of Fungicide Resistance in Botrytis cinerea from Strawberry in the Central Coast Region of California

2016 ◽  
Vol 17 (1) ◽  
pp. 30-34 ◽  
Author(s):  
Andrew Pokorny ◽  
Joseph Smilanick ◽  
Chang-Lin Xiao ◽  
James J. Farrar ◽  
Anil Shrestha
Keyword(s):  
Fungicide Resistance ◽  
Resistance Management ◽  
Gray Mold ◽  
Central Coast ◽  
Production Region ◽  
Management Measures ◽  
Highly Sensitive ◽  
Diseased Fruit ◽  
Grey Mold ◽  
Coast Region

Grey mold, caused by Botryis cinerea, is one of the most important diseases of strawberry in California. Management of grey mold typically relies on repeated fungicide applications. The occurrence of fungicide resistance in B. cinerea was examined in the Central Coast strawberry production region of California. In mid-May 2013, 59 samples consisting of a single diseased fruit or plant part with gray mold symptoms were collected from six different strawberry fields. Single hyphal tip cultures were then used for mycelial growth assays to compare sensitivities to four different fungicides—boscalid, fenhexamid, iprodione, and pyraclostrobin. Each isolate was tested against discriminatory doses of each of the fungicides. In addition, representative highly sensitive and highly resistant isolates were tested against a range of fungicide concentrations to determine EC50 values. Although all of the 59 isolates were sensitive to iprodione, 37%, 31%, and 29% of the isolates were resistant to pyraclostrobin, fenhexamid, and boscalid, respectively. In some instances the isolates were dual and triple-resistant to these fungicides. EC50 values were often higher than 100 mg/liter, which was the highest concentration used. Therefore, appropriate fungicide resistance management measures should be employed in strawberry growing areas of the Central Coast region of California. Accepted for publication 19 February 2016. Published 2 March 2016.

scholarly journals Fungicide resistance characterised across seven chemical classes in a Botrytis cinerea population isolated from Australian vineyards

2021 ◽  
Author(s):  
Lincoln A. Harper ◽  
Scott Paton ◽  
Barbara Hall ◽  
Suzanne McKay ◽  
Richard P. Oliver ◽  
...  
Keyword(s):  
Adverse Effect ◽  
Botrytis Cinerea ◽  
Fungicide Resistance ◽  
Chemical Control ◽  
Management Strategies ◽  
Resistance Management ◽  
Gray Mold ◽  
Chemical Groups ◽  
Important Disease ◽  
Selection Of

AbstractGray mold, caused by Botrytis cinerea, is an economically important disease of grapes in Australia and across grape growing regions worldwide. Control of this disease relies heavily on canopy management and the application of single site fungicides. Fungicide application can lead to the selection of fungicide resistant B. cinerea populations, which has an adverse effect on the chemical control of the disease. Characterising the distribution and severity of resistant B. cinerea populations is needed to inform resistance management strategies. In this study, 725 isolates were sampled from 75 Australian vineyards during 2013 – 2016 and were screened against seven fungicides with different MOAs. The resistance frequencies for azoxystrobin, boscalid, fenhexamid, fludioxonil, iprodione, pyrimethanil and tebuconazole were 5, 2.8, 2.1, 6.2, 11.6, 7.7 and 2.9% respectively. Nearly half of the resistant isolates (43.7%) were resistant to more than one of the fungicides tested. The frequency of vineyards with at least one isolate simultaneously resistant to 1, 2, 3, 4 or 5 fungicides was 19.5, 7.8, 6.5, 10.4 and 2.6%.Resistance was associated with previously published genotypes in CytB (G143A), SdhB (H272R/Y), Erg27 (F412S), Mrr1 (D354Y), Os1 (I365S, N373S + Q369P, I365S + D757N) and Pos5 (P319A, L412F). Expression analysis was used to characterise fludioxonil resistant isolates exhibiting overexpression (6.3 - 9.6-fold) of the ABC transporter encoded by AtrB (MDR1 phenotype). Novel genotypes were also described in Mrr1 (S611N, D616G) and Cyp51 (P357S). Resistance frequencies were lower when compared to most previously published surveys of both grape and non-grape B. cinerea resistance. Nonetheless, continued monitoring of critical chemical groups used in Australian vineyards is recommended.

scholarly journals Characterization of Botrytis cinerea From Commercial Cut Flower Roses

Plant Disease ◽  
2019 ◽  
Vol 103 (7) ◽  
pp. 1577-1583 ◽  
Author(s):  
M. Muñoz ◽  
J. E. Faust ◽  
G. Schnabel
Keyword(s):  
Botrytis Cinerea ◽  
Fungicide Resistance ◽  
Management Practices ◽  
Cultural Practices ◽  
Disease Incidence ◽  
Resistance Management ◽  
Gray Mold ◽  
Economic Losses ◽  
Cut Flower ◽  
Aspergillus Brasiliensis

Botrytis cinerea Pers. infects cut flower roses (Rosa × hybrida L.) during greenhouse production and gray mold symptoms are often expressed in the postharvest environment, resulting in significant economic losses. Disease management is based on cultural practices and preventative chemical treatments; however, gray mold outbreaks continue to occur. Rose tissues from six commercial shipments from two greenhouses in Colombia were evaluated to determine the Botrytis species composition as well as identify other pathogens present, gray mold incidence and severity, and fungicide resistance profiles. Botrytis isolates (49 total) were grouped into six morphological phenotypes, and all were identified to be B. cinerea sensu stricto. Disease incidence was higher in the petals than in the stem, stamen, ovary, sepal, or leaf tissues. Other fungi were isolated infrequently and included Alternaria alternata, Cladosporium cladosporioides, Epicoccum nigrum, Penicillium citrinum, Aspergillus brasiliensis, and Diplodia sp. Fungicide resistance profiles were determined using previously established discriminatory doses. Isolates resistant to thiophanate-methyl, iprodione, boscalid, and cyprodinil were found frequently in all shipments and in both greenhouses. The frequency of resistance to penthiopyrad, fenhexamid, fluopyram, isofetamid, and fludioxonil varied between shipments and greenhouses. No resistance to pydiflumetofen was observed at the discriminatory doses tested. Isolates with resistance to multiple chemical classes were commonly found. These results indicate that fungicide resistance management practices may improve preharvest and postharvest gray mold control of cut flower roses.

scholarly journals Fungicide Resistance Profiling in Botrytis cinerea Populations from Blueberry in California and Washington and Their Impact on Control of Gray Mold

Plant Disease ◽  
2016 ◽  
Vol 100 (10) ◽  
pp. 2087-2093 ◽  
Author(s):  
S. Saito ◽  
T. J. Michailides ◽  
C. L. Xiao
Keyword(s):  
Botrytis Cinerea ◽  
Fungicide Resistance ◽  
Resistance Management ◽  
Central Valley ◽  
Gray Mold ◽  
Postharvest Disease ◽  
Quinone Outside Inhibitor ◽  
Development Of Resistance ◽  
Western Washington ◽  
Moderately Resistant

Gray mold caused by Botrytis cinerea is a major postharvest disease of blueberry grown in the Central Valley of California and western Washington State. Sensitivities to boscalid, cyprodinil, fenhexamid, fludioxonil, and pyraclostrobin, representing five different fungicide classes, were examined for 249 (California) and 106 (Washington) B. cinerea isolates recovered from decayed blueberry fruit or flowers. In California and Washington, 7 and 17 fungicide-resistant phenotypes, respectively, were detected: 66 and 49% of the isolates were resistant to boscalid, 20 and 29% were moderately resistant to cyprodinil, 29 and 29% were resistant to fenhexamid, and 66 and 55% were resistant to pyraclostrobin. All isolates from California were sensitive to fludioxonil, whereas 70% of the isolates from Washington showed reduced sensitivity to fludioxonil. In California, 26 and 30% of the isolates were resistant to two and three classes of fungicides, respectively. In Washington, 31, 14, 16, and 9% of the isolates were resistant to two, three, four, and five classes of fungicides, respectively. Inherent risk of the development of resistance to quinone outside inhibitor (QoI) fungicides was assessed by detecting the presence of the Bcbi-143/144 intron in gene cytb. The intron was detected in 11.8 and 40% of the isolates in California and Washington, respectively, suggesting that the risk of QoI resistance is higher in California than in Washington. On detached blueberry fruit inoculated with 11 isolates exhibiting different fungicide-resistant phenotypes, most fungicides failed to control gray mold on fruit inoculated with the respective resistant phenotypes but the mixture of cyprodinil and fludioxonil was effective against all fungicide-resistant phenotypes tested. Our findings would be useful in designing and implementing fungicide resistance management spray programs for control of gray mold in blueberry.

scholarly journals Within-Season Shift in Fungicide Resistance Profiles of Botrytis cinerea in California Strawberry Fields

Plant Disease ◽  
2019 ◽  
Vol 103 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Scott D. Cosseboom ◽  
Kelly L. Ivors ◽  
Guido Schnabel ◽  
Patricia K. Bryson ◽  
Gerald J. Holmes
Keyword(s):  
Botrytis Cinerea ◽  
Fungicide Resistance ◽  
Mycelial Growth ◽  
Target Genes ◽  
Resistance Management ◽  
Gray Mold ◽  
Field Resistance ◽  
Early Season ◽  
Late Season ◽  
Growth Assay

Sensitivity of Botrytis cinerea to seven fungicide chemical classes was determined for 888 isolates collected in 2016 from 47 California strawberry fields. Isolates were collected early season (minimum fungicide exposure) and late season (maximum fungicide exposure) from the same planting block in each field. Resistance was determined using a mycelial growth assay, and variable frequencies of resistance were observed to each fungicide at both sampling times (early season %, late season %): boscalid (12, 35), cyprodinil (12, 46), fenhexamid (53, 91), fludioxonil (1, 4), fluopyram (2, 7), iprodione (25, 8), isofetamid (0, 1), penthiopyrad (8, 25), pyraclostrobin (77, 98), and thiophanate-methyl (81, 96). Analysis of number of chemical class resistances (CCRs) revealed an increasing shift in CCR from the early to late season. Phenotypes of 40 isolates that were resistant or sensitive to different chemical classes were associated with presence or absence of mutations in target genes. Fungicide-resistance phenotypes determined in the mycelial growth assay closely matched (93.8%) the genotype observed. Previously described resistance-conferring mutations were found for each gene. A survey of fungicide use from 32 of the sampled fields revealed an average of 15 applications of gray mold–labeled fungicides per season at an average interval of 12 days. The most frequently applied fungicides (average number of applications during the 2016 season) were captan (7.3), pyraclostrobin (2.5), cyprodinil (2.3), fludioxonil (2.3), boscalid (1.8), and fenhexamid (1.4). Multifungicide resistance is widespread in California. Resistance management tactics that reduce selection pressure by limiting fungicide use, rotating among Fungicide Resistance Action Committee codes, and mixing/rotating site-specific fungicides with multisite fungicides need to be improved and implemented.

scholarly journals Characterization of Resistance to Six Chemical Classes of Site-Specific Fungicides Registered for Gray Mold Control on Strawberry in Spain

Plant Disease ◽  
2016 ◽  
Vol 100 (11) ◽  
pp. 2234-2239 ◽  
Author(s):  
Dolores Fernández-Ortuño ◽  
Juan Antonio Torés ◽  
Manuel Chamorro ◽  
Alejandro Pérez-García ◽  
Antonio de Vicente
Keyword(s):  
Fungicide Resistance ◽  
Fungal Pathogens ◽  
Management Practices ◽  
Resistance Management ◽  
Gray Mold ◽  
Amino Acid Substitutions ◽  
Site Specific ◽  
Resistance Profile ◽  
The World

Botrytis cinerea, causal agent of the gray mold disease, is one of the most economically important fungal pathogens of strawberry worldwide. In Spain, as in other parts of the world, management of gray mold control primarily involves the application of fungicides. To determine the fungicide resistance of the Spanish strawberry field population, 367 B. cinerea isolates were examined from one organic and 13 conventional strawberry fields in Huelva (Spain) in 2014 and 2015. The sensitivities of these isolates to six fungicides used for gray mold management in Spain were examined using a spore germination assay based on previously published discriminatory doses. The frequency of resistance to pyraclostrobin, boscalid, cyprodinil, fenhexamid, iprodione, and fludioxonil was 74.6, 64.8, 37.0, 23.7, 14.7, and 0.8%, respectively. The majority of isolates (35.1%) were resistant to three different fungicides classes. Within these isolates, the most prevalent resistance profile (55.8%) was resistance to pyraclostrobin, boscalid, and cyprodinil, followed by the resistance profile (30.2%) of resistance to pyraclostrobin, boscalid, and fenhexamid. One isolate collected in 2015 was resistant to all six fungicide classes. Resistance to boscalid, fenhexamid, iprodione, and pyraclostrobin was found to be caused by amino acid substitutions on target proteins, including H272R/Y in SdhB, F412I/S/V in Erg27, I365 N/S in Bos1, and G143A in Cytb, respectively. The presence of multifungicide resistance phenotypes in B. cinerea isolates from strawberry fields in Spain must be considered in the development of future resistance management practices.

Fauna habitat modelling and mapping: A review and case study in the Lower Hunter Central Coast region of NSW

2005 ◽  
Vol 30 (7) ◽  
pp. 719-738 ◽  
Author(s):  
BRENDAN A. WINTLE ◽  
JANE ELITH ◽  
JOANNE M. POTTS
Keyword(s):  
Habitat Modelling ◽  
Central Coast ◽  
Coast Region

Prevention and Detection of Fungicide Resistance Development in Rhizoctonia zeae from Soybean and Corn in Nebraska

2021 ◽  
Author(s):  
Nikita Gambhir ◽  
Srikanth Kodati ◽  
Matthew Huff ◽  
Flávio Silva ◽  
Olutoyosi Ajayi-Oyetunde ◽  
...  
Keyword(s):  
Fungicide Resistance ◽  
Resistance Management ◽  
Dry Weight ◽  
Geographic Region ◽  
Population Characteristics ◽  
Current Status ◽  
In Planta ◽  
Resistance Development ◽  
Rhizoctonia Zeae

The goal of this research was to advance the foundational knowledge required to quantify and mitigate fungicide resistance in Rhizoctonia zeae, the seedling disease pathogen of soybean and corn. In vitro sensitivity to azoxystrobin, fludioxonil, sedaxane, and/or prothioconazole was determined for 91 R. zeae isolates obtained mostly from soybean and corn fields in Nebraska. Isolates were sensitive to fludioxonil, sedaxane, and prothioconazole (EC50 < 3 µg/ml) and had a positively skewed EC50 distribution. Isolates were not sensitive to azoxystrobin in vitro (EC50 > 100 µg/ml) or in planta. Application of azoxystrobin did not significantly decrease disease severity or improve total dry weight of the soybean plants (P > 0.05). The risk of resistance development in R. zeae was estimated by characterizing its population structure. Eighty-one R. zeae isolates were genotyped using six microsatellite markers. Results showed that the population has a mixed mode of reproduction and is structured according to geographic region, suggesting limited dispersal. These population characteristics suggest that R. zeae has an intermediate risk of resistance development. Overall, this research established the current status of fungicide sensitivity in R. zeae in Nebraska and estimated its risk of resistance development, which can inform fungicide resistance management for R. zeae.

scholarly journals Fungicide Resistance Management Guidelines for the Control of Tomato Diseases in the Mid-Atlantic and Northeast Regions of the United States

2010 ◽  
Vol 11 (1) ◽  
pp. 32 ◽  
Author(s):  
Christian A. Wyenandt ◽  
Steven L. Rideout ◽  
Beth K. Gugino ◽  
Margaret T. McGrath ◽  
Kathryne L. Everts ◽  
...  
Keyword(s):  
United States ◽  
Fungicide Resistance ◽  
Resistance Management ◽  
The United States ◽  
Management Tool ◽  
Fresh Market ◽  
Management Guidelines ◽  
Control Programs ◽  
Action Committee ◽  
Tomato Diseases

Foliar diseases and fruit rots occur routinely on tomato, an important crop grown throughout the Mid-Atlantic and Northeast regions of the United States where it is produced for both fresh-market and processing. To enable these tomato growers to more effectively manage economically important diseases, a fungicide resistance management table has been developed which promotes the importance of understanding FRAC (Fungicide Resistance Action Committee) codes and provides an integrated pest management tool for tomato growers which will allow them to develop season-long disease control programs with an emphasis on fungicide resistance management. Accepted for publication 19 July 2010. Published 27 August 2010.

scholarly journals Succinate dehydrogenase inhibitor (SDHI) fungicide resistance prevention strategy

2011 ◽  
Vol 64 ◽  
pp. 119-124 ◽  
Author(s):  
A.H. McKay ◽  
G.C. Hagerty ◽  
G.B. Follas ◽  
M.S. Moore ◽  
M.S. Christie ◽  
...  
Keyword(s):  
New Zealand ◽  
High Risk ◽  
Succinate Dehydrogenase ◽  
Fungicide Resistance ◽  
Fungal Pathogens ◽  
Resistance Management ◽  
Resistance Development ◽  
Development Of Resistance ◽  
Action Committee ◽  
Succinate Dehydrogenase Inhibitor

Succinate dehydrogenase inhibitor (SDHI) fungicides are currently represented in New Zealand by eight active ingredients bixafen boscalid carboxin fluaxapyroxad fluopyram isopyrazam penthiopyrad and sedaxane They are either currently registered or undergoing development in New Zealand for use against a range of ascomycete and basiodiomycete pathogens in crops including cereals ryegrass seed apples pears grapes stonefruit cucurbits and kiwifruit These fungicides are considered to have medium to high risk of resistance development and resistance management is recommended by the Fungicide Resistance Action Committee (FRAC) in Europe Guidelines are presented for use of SDHI fungicides in New Zealand to help avoid or delay the development of resistance in the fungal pathogens that they target

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