Plant Health Progress最新文献

{"title":"Soil Census of Kentucky High Tunnels Reveals Statewide Distribution of Two Meloidogyne Species","authors":"Victoria Bajek, M. Munir, R. Rudolph","doi":"10.1094/php-05-23-0052-s","DOIUrl":"https://doi.org/10.1094/php-05-23-0052-s","url":null,"abstract":"High tunnels are passively heated and cooled structures used for specialty crop production that can increase marketable yields, extend the growing season, and protect crops from harsh weather. Kentucky has more than 1,500 high tunnels and although there are many benefits, production still has several challenges. High soil temperatures, lack of rotation and sanitation, and intensive and continuous cropping make high tunnels hospitable environments for root-knot nematode (RKN; Meloidogyne spp.). This plant-parasite infects roots, causing chlorosis, wilting, stunting, and yield loss. Determining the presence, population density, and species of RKN is important to inform management strategies. To our knowledge, this is the first research aimed at determining the presence and distribution of RKN across Kentucky. From 2019 to 2022, we sampled the soil in 175 high tunnels in 62 counties. The characteristics of production system, soil type, crop rotation, and high tunnel age were collected to analyze with RKN presence, species, and soil population density. Of the soil samples collected, 45% had no presence of RKN. Out of 55% of total samples that had RKN identified, 55% were identified as M. incognita, 39% M. hapla, and 4% M. arenaria. Root-knot nematode presence was dependent on production system and crop rotation, whereas, RKN species was dependent on production system and soil type. With over half of the sampled high tunnels infested with RKN, this project justifies further research for management strategies for RKN, especially those that are sustainable species-specific options and appropriate for commercial high tunnels.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48647031","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}

{"title":"Variation in isolate virulence and accession resistance associated with Diaporthe aspalathi, D. caulivora, and D. longicolla in soybean","authors":"K. Mohan, B. Kontz, Paul N. Okello, T. Allen, G. Bergstrom, Kaitlyn M. Bissonnette, J. Bonkowski, C. Bradley, J. Buck, M. Chilvers, A. Dorrance, L. Giesler, H. Kelly, A. Koehler, H. Lopez-Nicora, D. Mangel, S. Markell, D. Mueller, P. Price, III, A. Rojas, Madalyn K. Shires, Damon L. Smith, T. Spurlock, R. Webster, K. Wise, D. Yabwalo, F. Mathew","doi":"10.1094/php-04-23-0041-rs","DOIUrl":"https://doi.org/10.1094/php-04-23-0041-rs","url":null,"abstract":"Important stem and grain diseases of soybean [Glycine max (L.) Merr.] caused by Diaporthe aspalathi, D. caulivora and D. longicolla reduce yield in the United States. Sources of resistance to these pathogens have previously been reported; however, there is limited information regarding their resistance when exposed to geographically distinct isolates of the same species. In this study, four accessions from the USDA Soybean Germplasm collection with reported resistance to either D. aspalathi, D. caulivora or D. longicolla were evaluated using geographically representative isolates within each species from the U.S. For each fungus, a greenhouse experiment was conducted as a completely randomized design with a factorial arrangement (isolate × accession). Plants were inoculated at the second to third trifoliate growth stage using toothpicks infested with isolates of each Diaporthe species. Pathogenicity was assessed 21 days post-inoculation as 0=no lesion, 0.5=lesion length>1 cm, and 1=dead plant. A significant isolate by accession interaction (P<0.05) was observed to affect pathogenicity as analyzed using non-parametric statistics (relative treatment effects, RTE) indicating that accessions responded differently to the isolates. Correlation analyses suggested that the RTEs on ‘Tracy-M’, ‘Dowling’ and ‘Crockett’ were weakly to moderately correlated with that of the D. aspalathi-susceptible ‘Bragg’, as well as for ‘PI567473B’, and ‘Century’ (D. caulivora), and ‘PI417507’ (D. longicolla) with the RTEs on ‘Hawkeye’ (P>0.05) indicating possible genetic variation for resistance within these accessions. Our results provide information related to the resistance of previously identified accessions to develop commercial cultivars with resistance to important pathogens within the genus Diaporthe.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45389987","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}

{"title":"Impact of soil type and placement of Xyway LFR fungicide on germination and growth of corn seedlings under a controlled setting.","authors":"N. Kleczewski","doi":"10.1094/php-05-23-0045-br","DOIUrl":"https://doi.org/10.1094/php-05-23-0045-br","url":null,"abstract":"Xyway LFR was released for use in corn as an in-furrow fungicide during 2020. Producers have raised concerns of reduced emergence and growth in corn plantings. Here we assessed the impact of Xyway LFR placement in relation to the seed for impacts on seedling emergence and growth in two contrasting soil types (sand vs topsoil) under controlled conditions. Soil was added to containers and five corn seeds were placed in a row in a furrow within each container. Xyway LFR was applied in a band at labelled rates at either 0 (directly on seed) 1.27, cm, 2.54 cm, or 5.08 cm away from the seed. Containers were maintained under a light bank and germination over time, as well as seedling biomass, was assessed. Statistical analysis indicated that plants in topsoil had greater germination rates and dry masses than plants in sand. Total plant dry masses were reduced relative to controls when Xyway LFR was placed 0 cm from the seed. However, when placed 2.54 or 5.08 cm from the seed, this impact was not evident. Potential phytotoxic effects may be mitigated by placing the product in a band at least 2.54 cm from the seed furrow.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48299234","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}

{"title":"First report of Stemphylium solani associated with leaf spot of cotton in New South Wales, Australia","authors":"C. P. Nguyen, D. Le","doi":"10.1094/php-05-23-0043-br","DOIUrl":"https://doi.org/10.1094/php-05-23-0043-br","url":null,"abstract":"Leaf spot of cotton caused by Alternaria species has been long considered a minor disease in Australia, especially when only highly resistant Upland cotton (Gossypium hirsutum) are grown in commercial fields lately. However, leaf spot outbreaks were reported when crop was grown under favourable conditions for the disease development. In this study, we for the first time fully characterised the association of Stemphylium solani with leaf spot of cotton in New South Wales, Australia. A total of 32 isolates were recovered from leaf-spot-diseased leaves collected in the 2021/22 growing season. Leaf spot symptoms often occur in small circular to irregular necrotic lesions, often surrounded with purple halo, and were indistinguishable to those caused by Alternaria species. Sequences of the ITS, GAPDH and calmodulin genes of the three representative isolates revealed 99.86 to 100% sequence identity to the type isolate of Stemphylium solani CBS 116586. In a Neighbor-Joining analysis of the concatenated sequences of the ITS, GAPDH and calmodulin loci, the three cotton isolates were well clustered within the S. solani with a bootstrap support of 100%, thus, confirming the identification. On two-true-leaf cotton seedlings, the three S. solani isolates were able to incite spot symptoms that were similar to those observed in the field. The same fungal pathogen was recovered from inoculated diseased leaves, thus, confirming Koch’s postulations.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":"1 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61309918","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}

{"title":"First Report of Alfalfa Mosaic Virus on Cowpea in the United States","authors":"R. Harveson, L. Porter","doi":"10.1094/php-03-23-0021-br","DOIUrl":"https://doi.org/10.1094/php-03-23-0021-br","url":null,"abstract":"Cowpea ( Vigna unguiculata) is grown on approximately 5,220 ha across California and several Midwestern and southern states. In August of 2020, a viral disease was observed infecting cowpea in commercial fields and research trials in Nebraska, United States. Based on RNA sequencing and serology, the virus species was identified as Alfalfa mosaic virus. To our knowledge, this is the first report of this virus on cowpea in the United States.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49587346","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}

{"title":"First report of Phytophthora citrophthora causing leaf necrosis and terminal shoot dieback on Asimina triloba (pawpaw) in a Virginia floodplain forest","authors":"Devin Bily, Tashi Gyatso","doi":"10.1094/php-05-23-0047-br","DOIUrl":"https://doi.org/10.1094/php-05-23-0047-br","url":null,"abstract":"Asimina triloba (pawpaw) is a shade-tolerant, understory, deciduous tree in the family Annonaceae that is native to 26 states in the eastern U.S. with a range from the Florida panhandle to New York, west to Iowa and Nebraska, and south to Texas. On 12 June 2022, in a floodplain forest along the James River near Richmond, Virginia, a group of three A. triloba saplings about 1.0 to 1.5 m tall were observed with leaf necrosis, terminal shoot dieback, and leaf drop. Symptomatic tissue was cultured on selective media and isolate DB22-4 was identified as Phytophthora citrophthora using morphological and molecular methods. A segment of the ITS and COX1 loci were deposited in the Genbank database under accession numbers OQ703042 and OQ834750, respectively. Koch’s postulates were fulfilled in a non-wounded, attached-leaf assay by inoculating 20 leaves on five healthy saplings. To the authors knowledge, this is the first report of P. citrophthora causing terminal necrosis and leaf drop on A. triloba in a nursery or a natural ecosystem. Additional studies are needed to understand the environmental and physiological factors that favor infection of A. triloba by P. citrophthora in the forest under natural conditions.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45115882","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}

{"title":"Conventional and Biopesticide Fungicides for Cucurbit Downy Mildew Control on Cucumber in Michigan","authors":"Matthew Ray Uebbing, Z. Hayden, M. Hausbeck","doi":"10.1094/php-03-23-0024-rs","DOIUrl":"https://doi.org/10.1094/php-03-23-0024-rs","url":null,"abstract":"Michigan ranks first in the nation in cucumber production for processing (pickling), contributing over $45 million to the state’s economy in 2019. Cucurbit downy mildew, caused by the oomycete Pseudoperonospora cubensis, is the most important disease of cucumber and an annual threat to yields. Fungicides are the most important means to control P. cubensis. Our goal was to monitor currently labelled conventional fungicides and biopesticides for efficacy over the course of an entire cropping period under high pathogen pressure. Field trials were conducted at the Michigan State University Plant Pathology Research Farm in 2021 and 2022. Fungicides were applied weekly and disease severity was evaluated by visually assessing the percentage of foliar area showing downy mildew symptoms. At the end of the season, relative area under the disease progress curve (rAUDPC) was calculated using the disease severity data. Based on rAUDPC results, oxathiapiprolin (OXTP) premixed with chlorothalonil was the most effective fungicide at controlling P. cubensis and was significantly better than all other conventional fungicides in both years tested. In both years, all conventional treatments had significantly lower rAUDPC than the untreated control except pyraclostrobin, dimethomorph, and fluopicolide. No biopesticide fungicide reduced rAUDPC compared to the untreated control in either year evaluated.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43859190","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}

{"title":"Fine fescue species vary in their susceptibility to snow molds","authors":"P. Koch, M. Chou, James Murphy, Kyle Genova, James W. Hempfling, B. Clarke","doi":"10.1094/php-06-23-0056-rs","DOIUrl":"https://doi.org/10.1094/php-06-23-0056-rs","url":null,"abstract":"Fine fescues are a group of turfgrass species that are often planted when low-input maintenance is desired. The five species most commonly associated with the fine fescues are strong creeping red fescue, slender creeping red fescue, Chewings fescue, sheep fescue, and hard fescue. Little is known about the resistance of fine fescues to snow mold diseases despite the widespread adoption of fine fescues across temperate climates with harsh winters. Field and controlled environment trials were conducted in Wisconsin and New Jersey between 2014 and 2017 to assess snow mold resistance among the fine fescues. In both the field and controlled environment, hard and sheep fescue were among the most resistant to snow molds and Chewings fescue was the most susceptible. However, significant variation existed among the cultivars within each species, suggesting that opportunities exist for breeding to improve resistance to snow mold in the fine fescues.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43263452","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}

{"title":"Prevalence, spatial distribution, and population density of plant-parasitic nematodes in vegetable fields of North Carolina, South Carolina, and Tennessee counties","authors":"Adrienne M. Gorny, E. Reeves, Andrew Scruggs, I. Meadows","doi":"10.1094/php-05-23-0044-s","DOIUrl":"https://doi.org/10.1094/php-05-23-0044-s","url":null,"abstract":"Plant-parasitic nematodes are a diverse group of soilborne plant pathogens that limit the yield of numerous vegetable crops globally. Few studies have investigated nematode populations affecting vegetable crops in Tennessee and North and South Carolinas. Between December 2020 and October 2022, vegetable fields in selected counties of these states were sampled for plant-parasitic nematodes. Data on the prevalence, spatial distribution, and population density of seven genera of plant-parasitic nematodes, identified via morphology, were collected. Root-knot nematodes were identified in 60% of the total fields sampled, with population densities ranging from 10 to 10,400 nematodes per 500 cc soil. Detection rates of other genera as percentage of total fields sampled were as follows: spiral (42%), stubby root (32%), stunt (21%), ring (13%), and lesion (8%) nematodes. Out of eight crops sampled, fields either currently or formerly planted to tomato or pepper were the most frequently sampled in the survey (77% of total fields). This is the first survey to collect data on populations of plant-parasitic nematodes in this region, and results highlight the need for continued surveillance and study of their impact in vegetable production.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46334294","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}

{"title":"Diet and injection, important recommendations to characterize Clavibacter michiganensis-tomato interactions","authors":"Annie Brochu, Jeanne Durivage, Dagoberto Torres Garcia, E. Pérez-López","doi":"10.1094/php-04-23-0040-rs","DOIUrl":"https://doi.org/10.1094/php-04-23-0040-rs","url":null,"abstract":"Tomato (Solanum lycopersicum L.) is one of the most important vegetables in the world. Its extensive cultivation has made this plant the target of many viral, fungal, and bacterial diseases. Among them, the bacterial canker of tomato caused by Clavibacter michiganensis (Cm) has been named one of the most devastating diseases affecting the tomato industry worldwide. It can significantly reduce the yields and profitability of this crop. One of the big challenges we found when working with Cm and trying to characterize the virulence of different isolates was the lack of a consensus methodology to inoculate tomato plants, how to fertilize them and characterize Cm virulence. This research aimed to identify an artificial inoculation method to induce bacterial canker on tomato plants in greenhouse conditions to homogenize the results of different studies with Cm. We compared two inoculation methods, including the scalpel and syringe method with two levels of fertilization, low and high fertilization. After evaluating several variables like the percentage of necrotic leaves and the height of the plants, the results showed that the syringe inoculation with low fertilization was the most effective inoculation method allowing the development of a multilevel scale that can be used to study the interaction between tomato plants and Cm isolates.","PeriodicalId":20251,"journal":{"name":"Plant Health Progress","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44793576","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}