Pub Date : 2023-12-19DOI: 10.1094/php-10-23-0084-dg
Christ Mane Belizaire, Lederson Gañán-Betancur, Romina Gazis
Avocado scab, caused by the fungus Elsinoe perseae, is a major disease of avocado (Persea americana). Diagnosis of avocado scab is hampered by the similarity that advanced symptoms have with fruit defects caused by other etiologies (e.g., mechanical injuries and insect feeding damage). This diagnostic guide aims to establish key aspects of the identification of symptoms and signs of avocado scab in the field and laboratory, and to provide guidance when conducting isolation, identification (i.e., based on morphological characters, molecular-based assays), maintenance, storage, and pathogenicity tests of the fungus E. perseae.
牛油果疮痂病是由真菌 Elsinoe perseae 引起的，是牛油果（Persea americana）的一种主要病害。牛油果疮痂病的晚期症状与其他病因（如机械损伤和昆虫食害）造成的果实缺陷相似，这妨碍了牛油果疮痂病的诊断。本诊断指南旨在确定在田间和实验室鉴别牛油果疮痂病症状和体征的关键方面，并为进行真菌 E. perseae 的分离、鉴别（即基于形态特征、分子检测）、养护、储藏和致病性试验提供指导。
{"title":"Avocado scab caused by Elsinoe perseae: A diagnostic guide","authors":"Christ Mane Belizaire, Lederson Gañán-Betancur, Romina Gazis","doi":"10.1094/php-10-23-0084-dg","DOIUrl":"https://doi.org/10.1094/php-10-23-0084-dg","url":null,"abstract":"Avocado scab, caused by the fungus Elsinoe perseae, is a major disease of avocado (Persea americana). Diagnosis of avocado scab is hampered by the similarity that advanced symptoms have with fruit defects caused by other etiologies (e.g., mechanical injuries and insect feeding damage). This diagnostic guide aims to establish key aspects of the identification of symptoms and signs of avocado scab in the field and laboratory, and to provide guidance when conducting isolation, identification (i.e., based on morphological characters, molecular-based assays), maintenance, storage, and pathogenicity tests of the fungus E. perseae.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":" 32","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138962363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-19DOI: 10.1094/php-08-23-0070-rs
Benjamin Waldo, Maria Mendes, William T. Crow
Subsurface seep irrigation is a common practice in Florida histosol soils to supply water to crops by utilizing high water tables. This study evaluated the effect of subsurface and overhead irrigation methods on plant-parasitic and free-living nematode densities in 46 cm soil lysimeters in a greenhouse study. Lysimeters were planted with bahiagrass in 2019 and wheat in 2020 and irrigated with subsurface or overhead irrigation for 12 weeks. Nematodes were extracted and quantified at 5 cm depth increments. Nematode counts were subjected to analysis of variance to compare treatment effects. Among nematode functional groups, omnivores were the most affected by irrigation method, their abundance being lower in subsurface irrigated lysimeters than in overhead irrigated ones. The results of this study show omnivore nematode density and depth distribution are impacted by irrigation method.
{"title":"Subsurface Seep Irrigation Effects on Omnivorous Nematode Vertical Distribution in Lysimeters","authors":"Benjamin Waldo, Maria Mendes, William T. Crow","doi":"10.1094/php-08-23-0070-rs","DOIUrl":"https://doi.org/10.1094/php-08-23-0070-rs","url":null,"abstract":"Subsurface seep irrigation is a common practice in Florida histosol soils to supply water to crops by utilizing high water tables. This study evaluated the effect of subsurface and overhead irrigation methods on plant-parasitic and free-living nematode densities in 46 cm soil lysimeters in a greenhouse study. Lysimeters were planted with bahiagrass in 2019 and wheat in 2020 and irrigated with subsurface or overhead irrigation for 12 weeks. Nematodes were extracted and quantified at 5 cm depth increments. Nematode counts were subjected to analysis of variance to compare treatment effects. Among nematode functional groups, omnivores were the most affected by irrigation method, their abundance being lower in subsurface irrigated lysimeters than in overhead irrigated ones. The results of this study show omnivore nematode density and depth distribution are impacted by irrigation method.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":" 20","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138960759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-27DOI: 10.1094/php-08-23-0073-br
K. Dey, M. Velez-Climent, Patricia Soria, John D. McVay, Scott Adkins
Over the past 24 years, virus-like symptoms have been observed on Jasminum spp. in Florida. In September 2018, symptomatic Angelwing jasmine leaves from a hedge in Alachua, Florida were tested for jasmine mosaic-associated virus (JMaV) and jasmine virus H (JaVH). Identification of expected size amplicons was confirmed by sequencing (Accession No. MN245037, MT559755). In December 2018, symptomatic samples from two Gold Coast jasmine plants from St. Lucie County, Florida were similarly tested. Only JaVH tested positive (Accession No. MN442626). In July 2019, Angelwing jasmine hedge in Orange County, Florida, exhibiting similar symptoms tested positive only for JaVH (GenBank accession MN442627). In April 2023, samples from a symptomatic Gold Coast jasmine hedge in Indian River County, Florida, also tested positive only for JaVH. In May 2023, a symptomatic Angelwing jasmine sample from Miami-Dade County tested positive for both JMaV and JaVH. This is the first report of JMaV and JaVH in single or mixed infections in jasmine in Florida, adding to the known virus species infecting jasmine in the state. Since jasmine is propagated vegetatively, it is likely that dissemination of cuttings made from infected plants is responsible for widespread distribution of these viruses.
{"title":"First report of mixed infection of jasmine mosaic associated virus (JMaV) and jasmine virus H (JaVH) in Jasmine spp. in Florida, USA","authors":"K. Dey, M. Velez-Climent, Patricia Soria, John D. McVay, Scott Adkins","doi":"10.1094/php-08-23-0073-br","DOIUrl":"https://doi.org/10.1094/php-08-23-0073-br","url":null,"abstract":"Over the past 24 years, virus-like symptoms have been observed on Jasminum spp. in Florida. In September 2018, symptomatic Angelwing jasmine leaves from a hedge in Alachua, Florida were tested for jasmine mosaic-associated virus (JMaV) and jasmine virus H (JaVH). Identification of expected size amplicons was confirmed by sequencing (Accession No. MN245037, MT559755). In December 2018, symptomatic samples from two Gold Coast jasmine plants from St. Lucie County, Florida were similarly tested. Only JaVH tested positive (Accession No. MN442626). In July 2019, Angelwing jasmine hedge in Orange County, Florida, exhibiting similar symptoms tested positive only for JaVH (GenBank accession MN442627). In April 2023, samples from a symptomatic Gold Coast jasmine hedge in Indian River County, Florida, also tested positive only for JaVH. In May 2023, a symptomatic Angelwing jasmine sample from Miami-Dade County tested positive for both JMaV and JaVH. This is the first report of JMaV and JaVH in single or mixed infections in jasmine in Florida, adding to the known virus species infecting jasmine in the state. Since jasmine is propagated vegetatively, it is likely that dissemination of cuttings made from infected plants is responsible for widespread distribution of these viruses.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":"30 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139230731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-21DOI: 10.1094/php-07-23-0064-sc
Zen McKenzie, Max Sturdivant, Jake Ueckert, Kevin L. Ong
A constant challenge experienced by plant diagnostic laboratories is having reliable and readily available controls. Often, requests must be made from colleagues to obtain materials for use as controls. This can be problematic if the pathogen is not present in the country and/or is subject to regulations. gBlocks™ are synthetic oligonucleotides that are widely used in genomic-based applications and studies. We evaluated the use of synthesized gBlocks™ as a positive control for tomato brown rugose fruit virus (ToBRFV) in a seed extraction PCR (SE-PCR) assay. ToBRFV is a highly virulent Tobamovirus that expresses symptoms of mosaic patterns, browning, and undersized wrinkled fruits in tomatoes, peppers, and other solanaceous plants. Transmission occurs in the seeds and can spread via mechanical contamination of equipment, humans, and other infected plants. Regulations with ToBRFV in the US makes it difficult to obtain a positive biological control for use in diagnostic clinics. Therefore, we wanted to assess if this synthetic oligonucleotide could serve as a process control. In our study, pepper (Capsicum annuum) seeds were “spiked” with synthesized oligonucleotides, which were then used as a point of comparison to biologically positive seeds and negative controls by way of quantifying viral titer. The stability of these synthesized oligonucleotides was evaluated over several temperatures and temporal parameters. Our results suggest that the oligonucleotides are suitable for use in the production of synthetically contaminated seeds that are to be used as a positive control in the validation of the diagnostic process for ToBRFV.
{"title":"Evaluating the utilization of synthetic oligonucleotides as a positive control in the detection of ToBRFV in pepper seeds","authors":"Zen McKenzie, Max Sturdivant, Jake Ueckert, Kevin L. Ong","doi":"10.1094/php-07-23-0064-sc","DOIUrl":"https://doi.org/10.1094/php-07-23-0064-sc","url":null,"abstract":"A constant challenge experienced by plant diagnostic laboratories is having reliable and readily available controls. Often, requests must be made from colleagues to obtain materials for use as controls. This can be problematic if the pathogen is not present in the country and/or is subject to regulations. gBlocks™ are synthetic oligonucleotides that are widely used in genomic-based applications and studies. We evaluated the use of synthesized gBlocks™ as a positive control for tomato brown rugose fruit virus (ToBRFV) in a seed extraction PCR (SE-PCR) assay. ToBRFV is a highly virulent Tobamovirus that expresses symptoms of mosaic patterns, browning, and undersized wrinkled fruits in tomatoes, peppers, and other solanaceous plants. Transmission occurs in the seeds and can spread via mechanical contamination of equipment, humans, and other infected plants. Regulations with ToBRFV in the US makes it difficult to obtain a positive biological control for use in diagnostic clinics. Therefore, we wanted to assess if this synthetic oligonucleotide could serve as a process control. In our study, pepper (Capsicum annuum) seeds were “spiked” with synthesized oligonucleotides, which were then used as a point of comparison to biologically positive seeds and negative controls by way of quantifying viral titer. The stability of these synthesized oligonucleotides was evaluated over several temperatures and temporal parameters. Our results suggest that the oligonucleotides are suitable for use in the production of synthetically contaminated seeds that are to be used as a positive control in the validation of the diagnostic process for ToBRFV.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":"1 7","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139253125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-21DOI: 10.1094/php-09-23-0077-s
Madalyn K. Shires, C. Molnar, Alice A. Wright, G. Bishop, Scott Harper
Little cherry virus 2 (LChV2) is the causal agent of little cherry disease, a recurring problem affecting cherry production the U.S. Pacific Northwest. Previous research has shown that there are two genotypes (LC5 and Rube-74) of LChV2 present in Washington. Here we used data and samples from 2017-2022 to determine the incidence of each genotype in the PNW, their distribution in cultivated vs. ornamental host systems, and for evidence of co-infection of both genotypes in individual plants. We found that there was no geographic pattern in Washington, as both genotypes are distributed throughout the state, while in Oregon LChV2 positives were concentrated on one region. In both states, the LC5 genotype was the most common and widespread of the two genotypes, suggesting the Rube-74-like isolates found are more recently introduced, but are being actively transmitted. There were no host-specific patterns found as both genotypes were found in cultivated and ornamental cultivars. Co-infection of a single plant by both genotypes was common in both states, with no evidence of superinfection-exclusion, although interestingly, LChV2 titer and frequency decreased in the presence of ‘Candidatus Phytoplasma pruni’. Cumulatively, these data will help us better understand the epidemiology of this pathogen in the Pacific Northwest.
{"title":"Distribution and frequency of little cherry virus 2 genotypes in both production and ornamental fruit trees in the Pacific Northwest","authors":"Madalyn K. Shires, C. Molnar, Alice A. Wright, G. Bishop, Scott Harper","doi":"10.1094/php-09-23-0077-s","DOIUrl":"https://doi.org/10.1094/php-09-23-0077-s","url":null,"abstract":"Little cherry virus 2 (LChV2) is the causal agent of little cherry disease, a recurring problem affecting cherry production the U.S. Pacific Northwest. Previous research has shown that there are two genotypes (LC5 and Rube-74) of LChV2 present in Washington. Here we used data and samples from 2017-2022 to determine the incidence of each genotype in the PNW, their distribution in cultivated vs. ornamental host systems, and for evidence of co-infection of both genotypes in individual plants. We found that there was no geographic pattern in Washington, as both genotypes are distributed throughout the state, while in Oregon LChV2 positives were concentrated on one region. In both states, the LC5 genotype was the most common and widespread of the two genotypes, suggesting the Rube-74-like isolates found are more recently introduced, but are being actively transmitted. There were no host-specific patterns found as both genotypes were found in cultivated and ornamental cultivars. Co-infection of a single plant by both genotypes was common in both states, with no evidence of superinfection-exclusion, although interestingly, LChV2 titer and frequency decreased in the presence of ‘Candidatus Phytoplasma pruni’. Cumulatively, these data will help us better understand the epidemiology of this pathogen in the Pacific Northwest.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":"305 5","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139253921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-16DOI: 10.1094/php-09-23-0075-rs
William P. Gura, J. Gelain, Guido Schnabel
Polyoxin-D is a microbial fermentation product registered to control multiple crop diseases. However, there is limited knowledge of the effect of polyoxin-D against peach brown rot or potential efficacy improvements through combinations with essential or mineral oils. In this study, we evaluated the efficacy of polyoxin-D with or without thyme oil or mineral oil to control brown rot on peach caused by Monilinia frucicola in a multiyear study. Treatments were applied preharvest and included OSO 5% (polyoxin-D), OSO 5% + ThymeGuard 0.25% (polyoxin-D + thyme oil), and OSO 5% + PureSpray Green 0.5% (polyoxin-D + mineral oil). Assessment of preharvest brown rot revealed that the OSO 5% treatment had less disease incidence (9.4% on average) compared to the untreated control (20.0% on average), but no significant differences were found between OSO 5% + PureSpray Green (11.8% on average) and OSO 5% + ThymeGuard (11.4% on average). All three OSO 5% treatments reduced postharvest brown rot compared to the untreated control, but there were no significant differences in disease incidence between experimental treatments. Phytotoxicity was observed in the form of premature leaf drop. The greatest leaf drop was recorded for OSO 5% + PureSpray Green with 36.5% blind nodes on average. In summary, polyoxin D (OSO 5%), when applied by handgun to runoff using 1870 L/ha water volume, significantly reduced preharvest and postharvest brown rot disease but caused some premature leaf drop. The addition of thyme oil or mineral oil did not improve its efficacy.
多抗霉素-D 是一种微生物发酵产品，已注册用于防治多种作物病害。然而，人们对多效霉素-D 防治桃褐腐病的效果，或通过与精油或矿物油的组合提高药效的潜力了解有限。在本研究中，我们通过一项多年期研究，评估了多抗霉素-D 与百里香油或矿物油混合使用或不混合使用对防治由果核菌引起的桃褐腐病的功效。处理方法是在采收前施用，包括 5%的 OSO（多氧菌素-D）、5%的 OSO + 0.25% 的 ThymeGuard（多氧菌素-D + 百里香油）和 5%的 OSO + 0.5% 的 PureSpray Green（多氧菌素-D + 矿物油）。对收获前褐腐病的评估显示，与未处理的对照组（平均 20.0%）相比，OSO 5%处理的病害发生率较低（平均 9.4%），但 OSO 5% + PureSpray Green（平均 11.8%）和 OSO 5% + ThymeGuard（平均 11.4%）之间没有发现显著差异。与未处理的对照组相比，所有三种 OSO 5% 处理都能减少收获后褐腐病的发生，但不同试验处理之间的病害发生率没有明显差异。植物毒性表现为过早落叶。OSO 5% + PureSpray Green 的落叶率最高，平均盲节率为 36.5%。总之，多抗氧化剂 D（OSO 5%）在使用 1870 升/公顷水量的径流中用手喷枪施用时，可显著减少收获前和收获后的褐腐病，但会造成一些过早落叶。添加百里香油或矿物油并不能提高其功效。
{"title":"Influence of preharvest polyoxin-D applications with or without spray oils on brown rot development and tree health of peach","authors":"William P. Gura, J. Gelain, Guido Schnabel","doi":"10.1094/php-09-23-0075-rs","DOIUrl":"https://doi.org/10.1094/php-09-23-0075-rs","url":null,"abstract":"Polyoxin-D is a microbial fermentation product registered to control multiple crop diseases. However, there is limited knowledge of the effect of polyoxin-D against peach brown rot or potential efficacy improvements through combinations with essential or mineral oils. In this study, we evaluated the efficacy of polyoxin-D with or without thyme oil or mineral oil to control brown rot on peach caused by Monilinia frucicola in a multiyear study. Treatments were applied preharvest and included OSO 5% (polyoxin-D), OSO 5% + ThymeGuard 0.25% (polyoxin-D + thyme oil), and OSO 5% + PureSpray Green 0.5% (polyoxin-D + mineral oil). Assessment of preharvest brown rot revealed that the OSO 5% treatment had less disease incidence (9.4% on average) compared to the untreated control (20.0% on average), but no significant differences were found between OSO 5% + PureSpray Green (11.8% on average) and OSO 5% + ThymeGuard (11.4% on average). All three OSO 5% treatments reduced postharvest brown rot compared to the untreated control, but there were no significant differences in disease incidence between experimental treatments. Phytotoxicity was observed in the form of premature leaf drop. The greatest leaf drop was recorded for OSO 5% + PureSpray Green with 36.5% blind nodes on average. In summary, polyoxin D (OSO 5%), when applied by handgun to runoff using 1870 L/ha water volume, significantly reduced preharvest and postharvest brown rot disease but caused some premature leaf drop. The addition of thyme oil or mineral oil did not improve its efficacy.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":"13 2","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139267376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-09DOI: 10.1094/php-07-23-0069-rs
Rachel E. Rudolph, Ed Dixon, Misbakhul Munir, Kimberly Leonberger, Kathryn Pettigrew, Martin Polo, Henry S. Smith, Victoria Bajek, Lauren Irwin, Nicole Ward Gauthier
Lettuce is a high-value crop commonly grown in high tunnels. However, lettuce drop, caused by Sclerotinia sclerotiorum, can greatly impact lettuce production and profitability. Crop loss from S. sclerotiorum can be especially severe in high tunnels because of intensive cropping and limited options for non-host rotations. A study was conducted in a Kentucky high tunnel infested with S. sclerotiorum to determine if soil moisture, planting date, and host resistance can successfully manage lettuce drop. The experiment was arranged in a split-split plot design with soil moisture (high: 60-100%, low: 40-80% plant available water), planting date (early, mid, and late spring), and lettuce cultivar (Galactic, Harmony, Pirat, and Vulcan) being the main plot, subplot, and sub-subplot factors, respectively. In year one, lettuce drop incidence was significantly lower in the low soil moisture and early planting date, and significantly higher in ‘Pirat’ lettuce. Marketable lettuce weight was significantly higher in the late planting and ‘Vulcan’ treatments. In year two, lettuce drop incidence was significantly lower in the late planting and ‘Galactic’ lettuce compared to all other treatments. There was no significant difference in lettuce drop incidence between the high and low soil moisture in year two. Harmony and Vulcan had significantly higher marketable weight compared to all cultivars. Planting date and lettuce cultivar had the strongest effect on lettuce drop incidence. Although mid-spring is considered the ideal time to plant lettuce in Kentucky, growers managing lettuce drop should consider planting earlier or later and selecting resistant cultivars appropriate for their markets.
{"title":"Potential for Cultural Management of Lettuce Drop (Sclerotinia sclerotiorum) in High Tunnels through Modification of Soil Moisture, Planting Date, and Cultivar","authors":"Rachel E. Rudolph, Ed Dixon, Misbakhul Munir, Kimberly Leonberger, Kathryn Pettigrew, Martin Polo, Henry S. Smith, Victoria Bajek, Lauren Irwin, Nicole Ward Gauthier","doi":"10.1094/php-07-23-0069-rs","DOIUrl":"https://doi.org/10.1094/php-07-23-0069-rs","url":null,"abstract":"Lettuce is a high-value crop commonly grown in high tunnels. However, lettuce drop, caused by Sclerotinia sclerotiorum, can greatly impact lettuce production and profitability. Crop loss from S. sclerotiorum can be especially severe in high tunnels because of intensive cropping and limited options for non-host rotations. A study was conducted in a Kentucky high tunnel infested with S. sclerotiorum to determine if soil moisture, planting date, and host resistance can successfully manage lettuce drop. The experiment was arranged in a split-split plot design with soil moisture (high: 60-100%, low: 40-80% plant available water), planting date (early, mid, and late spring), and lettuce cultivar (Galactic, Harmony, Pirat, and Vulcan) being the main plot, subplot, and sub-subplot factors, respectively. In year one, lettuce drop incidence was significantly lower in the low soil moisture and early planting date, and significantly higher in ‘Pirat’ lettuce. Marketable lettuce weight was significantly higher in the late planting and ‘Vulcan’ treatments. In year two, lettuce drop incidence was significantly lower in the late planting and ‘Galactic’ lettuce compared to all other treatments. There was no significant difference in lettuce drop incidence between the high and low soil moisture in year two. Harmony and Vulcan had significantly higher marketable weight compared to all cultivars. Planting date and lettuce cultivar had the strongest effect on lettuce drop incidence. Although mid-spring is considered the ideal time to plant lettuce in Kentucky, growers managing lettuce drop should consider planting earlier or later and selecting resistant cultivars appropriate for their markets.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":" 20","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135241206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-05DOI: 10.1094/php-07-23-0065-rs
Abbeah Mae Navasca, Sandesh Dangi, Suzette Arcibal Baldwin, Zhao Jin, Thomas Baldwin
Fusarium Head Blight (FHB) is a devastating disease commonly affecting North American small grains, primarily caused by Fusarium graminearum. Although the disease causes visible symptoms, the more pressing concern is the contamination of grain with trichothecene toxins, especially deoxynivalenol (DON), which can cause toxicity in humans and animals by inhibiting protein biosynthesis. The DON levels are more critical when breeding for resistance, but it does not account for pathogen infection and disease severity. To link DON and Fusarium infection, we optimized and validated a real-time multiplex quantitative PCR (qPCR) protocol for high-throughput quantification of Fusarium biomass based on the Tri5 gene, which encodes trichodiene synthase, the first enzyme involved in trichothecene toxin production. The primers and probes were designed to measure the abundance of Tri5 and normalized to the barley actin gene. The assay is repeatable, robust, and sensitive, up to 0.003 ng/ul of F. graminearum and 0.3 ng/ul of barley DNA. The method is cost-effective and has the potential to quantify Fusarium biomass, monitor disease progression, and determine DON levels in barley spikes and harvested grains.
赤霉病(Fusarium Head Blight, FHB)是一种通常影响北美小谷物的毁灭性疾病，主要由赤霉病引起。虽然该病引起明显的症状，但更紧迫的问题是粮食受到毛霉菌毒素的污染，特别是脱氧雪腐镰刀菌醇(DON)，它可以通过抑制蛋白质的生物合成而对人类和动物造成毒性。DON水平在抗性育种中更为关键，但它不能解释病原体感染和疾病严重程度。为了将DON与镰刀菌感染联系起来，我们优化并验证了一种基于Tri5基因的实时多重定量PCR (qPCR)方案，该方案用于镰刀菌生物量的高通量定量，该基因编码毛霉烯合成酶，这是第一个参与毛霉毒素产生的酶。引物和探针用于测量Tri5的丰度，并归一化为大麦肌动蛋白基因。该方法重复性好，灵敏度高，可检测到0.003 ng/ul的禾谷镰刀菌和0.3 ng/ul的大麦DNA。该方法具有成本效益，有可能量化镰刀菌生物量，监测疾病进展，并确定大麦穗和收获谷物中的DON水平。
{"title":"Development and Validation of a Taq-man Multiplex qPCR Assay for High-Throughput Quantification of <i>Fusarium graminearum</i> Biomass in Barley Spikes and Grains","authors":"Abbeah Mae Navasca, Sandesh Dangi, Suzette Arcibal Baldwin, Zhao Jin, Thomas Baldwin","doi":"10.1094/php-07-23-0065-rs","DOIUrl":"https://doi.org/10.1094/php-07-23-0065-rs","url":null,"abstract":"Fusarium Head Blight (FHB) is a devastating disease commonly affecting North American small grains, primarily caused by Fusarium graminearum. Although the disease causes visible symptoms, the more pressing concern is the contamination of grain with trichothecene toxins, especially deoxynivalenol (DON), which can cause toxicity in humans and animals by inhibiting protein biosynthesis. The DON levels are more critical when breeding for resistance, but it does not account for pathogen infection and disease severity. To link DON and Fusarium infection, we optimized and validated a real-time multiplex quantitative PCR (qPCR) protocol for high-throughput quantification of Fusarium biomass based on the Tri5 gene, which encodes trichodiene synthase, the first enzyme involved in trichothecene toxin production. The primers and probes were designed to measure the abundance of Tri5 and normalized to the barley actin gene. The assay is repeatable, robust, and sensitive, up to 0.003 ng/ul of F. graminearum and 0.3 ng/ul of barley DNA. The method is cost-effective and has the potential to quantify Fusarium biomass, monitor disease progression, and determine DON levels in barley spikes and harvested grains.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":"134 31","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135724772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-16DOI: 10.1094/php-08-23-0072-rs
Sarah Jane Pethybridge, Kellie Damann, Sean Murphy, Kaitlin Diggins, Mark L. Gleason
Organic production of cucurbits in New York (NY) is challenged by a complex of biotic stresses, including insect pests, diseases, and weeds. The recent emergence of cucurbit yellow vine disease (CYVD), caused by the bacterium Serratia marcescens and spread by squash bugs (Anasa tristis), in NY is of urgent concern due to the lack of synthetic insecticide alternatives and effective complementary organic management practices. Cucurbit productivity is also related to effective weed management in the furrow (inter-row space between the raised beds) to prevent resource competition for plant growth and ease of harvesting. Field trials were conducted in organic acorn squash (cv. Table Ace) during 2021 and 2022 to evaluate the effect of exclusion netting in a mesotunnel on pest populations, disease incidence, and weed management techniques in the furrow. Treatments were landscape fabric in the furrow with or without a mesotunnel and a mesotunnel with either a ryegrass/white clover or ryegrass cover crop in the furrow. Mesotunnels significantly reduced squash bug populations and CYVD but did not affect the incidence of the predominant foliar diseases, powdery mildew, downy mildew, or Alternaria leaf spot. The ryegrass/white clover and ryegrass cover crops produced equivalent biomass and weed suppression in the furrow. Treatments had no significant effect on fruit number or weight, or the number of marketable fruit, but mesotunnels reduced the incidence of soft and sunburned fruit. The trade-offs and benefits of mesotunnels and furrow management for organic acorn squash production are discussed.
{"title":"Optimizing Integrated Pest Management in Mesotunnels for Organic Acorn Squash in New York","authors":"Sarah Jane Pethybridge, Kellie Damann, Sean Murphy, Kaitlin Diggins, Mark L. Gleason","doi":"10.1094/php-08-23-0072-rs","DOIUrl":"https://doi.org/10.1094/php-08-23-0072-rs","url":null,"abstract":"Organic production of cucurbits in New York (NY) is challenged by a complex of biotic stresses, including insect pests, diseases, and weeds. The recent emergence of cucurbit yellow vine disease (CYVD), caused by the bacterium Serratia marcescens and spread by squash bugs (Anasa tristis), in NY is of urgent concern due to the lack of synthetic insecticide alternatives and effective complementary organic management practices. Cucurbit productivity is also related to effective weed management in the furrow (inter-row space between the raised beds) to prevent resource competition for plant growth and ease of harvesting. Field trials were conducted in organic acorn squash (cv. Table Ace) during 2021 and 2022 to evaluate the effect of exclusion netting in a mesotunnel on pest populations, disease incidence, and weed management techniques in the furrow. Treatments were landscape fabric in the furrow with or without a mesotunnel and a mesotunnel with either a ryegrass/white clover or ryegrass cover crop in the furrow. Mesotunnels significantly reduced squash bug populations and CYVD but did not affect the incidence of the predominant foliar diseases, powdery mildew, downy mildew, or Alternaria leaf spot. The ryegrass/white clover and ryegrass cover crops produced equivalent biomass and weed suppression in the furrow. Treatments had no significant effect on fruit number or weight, or the number of marketable fruit, but mesotunnels reduced the incidence of soft and sunburned fruit. The trade-offs and benefits of mesotunnels and furrow management for organic acorn squash production are discussed.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136079740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-10DOI: 10.1094/php-07-23-0066-rs
Matthew Ray Uebbing, Zachary D. Hayden, Mary K. Hausbeck
Cucumber production is important to Michigan’s economy and was valued at more than $45 million in 2019. Cucurbit downy mildew (CDM), caused by Pseudoperonospora cubensis, is an annual threat to Michigan’s cucumber production and fungicides must be applied frequently to prevent major yield losses. Our objective was to evaluate the disease forecasting models, TOM-CAST, BLITE-CAST, and DM-CAST, for their application in scheduling fungicide applications for CDM control. Field trials were conducted in 2021 and 2022 to evaluate each disease forecaster at different spray thresholds compared to 7- and 10-day programs, and an untreated control. In 2021, all treatments received applications of cyazofamid alternated with oxathiapiprolin/chlorothalonil alternated with ametoctradin/dimethomorph plus chlorothalonil. The 2022 fungicide program was similar to 2021 except that cyazofamid was tank-mixed with chlorothalonil. Treatment plots were visually assessed for the foliar area (%) with CDM symptoms and relative area under the disease progress curve (rAUDPC) was determined at the end of each season. Results indicate that using DM-CAST or BLITE-CAST to schedule fungicide applications limited CDM and was similar to the 7-day program. The 7-day program received 7 (2021) and 6 (2022) applications whereas DM-CAST and BLITE-CAST required 4 to 8 or 5 to 6 applications, respectively, depending on the threshold and year. This is the first study to evaluate these disease forecasters for scheduling fungicide application intervals for CDM.
{"title":"Scheduling Fungicide Applications for Cucurbit Downy Mildew Control on Pickling Cucumber in Michigan using Disease Forecasters","authors":"Matthew Ray Uebbing, Zachary D. Hayden, Mary K. Hausbeck","doi":"10.1094/php-07-23-0066-rs","DOIUrl":"https://doi.org/10.1094/php-07-23-0066-rs","url":null,"abstract":"Cucumber production is important to Michigan’s economy and was valued at more than $45 million in 2019. Cucurbit downy mildew (CDM), caused by Pseudoperonospora cubensis, is an annual threat to Michigan’s cucumber production and fungicides must be applied frequently to prevent major yield losses. Our objective was to evaluate the disease forecasting models, TOM-CAST, BLITE-CAST, and DM-CAST, for their application in scheduling fungicide applications for CDM control. Field trials were conducted in 2021 and 2022 to evaluate each disease forecaster at different spray thresholds compared to 7- and 10-day programs, and an untreated control. In 2021, all treatments received applications of cyazofamid alternated with oxathiapiprolin/chlorothalonil alternated with ametoctradin/dimethomorph plus chlorothalonil. The 2022 fungicide program was similar to 2021 except that cyazofamid was tank-mixed with chlorothalonil. Treatment plots were visually assessed for the foliar area (%) with CDM symptoms and relative area under the disease progress curve (rAUDPC) was determined at the end of each season. Results indicate that using DM-CAST or BLITE-CAST to schedule fungicide applications limited CDM and was similar to the 7-day program. The 7-day program received 7 (2021) and 6 (2022) applications whereas DM-CAST and BLITE-CAST required 4 to 8 or 5 to 6 applications, respectively, depending on the threshold and year. This is the first study to evaluate these disease forecasters for scheduling fungicide application intervals for CDM.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136357847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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