An overview of pathogens associated with biotic stresses in hemp crops in Oregon, 2019-2020

Plant Disease ◽  
2021 ◽  
Author(s):  
Hannah M. Rivedal ◽  
Cassandra Funke ◽  
Kenneth Frost

Hemp (Cannabis sativa) acreage in Oregon has increased by approximately 240 times in the last five years and a greater number of hemp diseases have been observed. This special report documents pathogens, particularly those causing virus and virus-like diseases, that have been detected from field and greenhouse-grown hemp crops in Oregon, based on plant samples submitted to the Hermiston Agricultural Research and Extension Center Plant Clinic of Oregon State University in 2019 and 2020. Symptoms and signs were used to evaluate disease types and determine diagnostic assays used on each submission. Plants with signs or symptoms of fungal or oomycete infection were cultured to isolate pathogenic organisms and plants with symptoms suspected to be caused by virus infection were assayed for the presence of Beet curly top virus (BCTV), viroids, and phytoplasmas using polymerase chain reaction (PCR), or reverse transcription (RT)-PCR. Diseases with fungal or oomycete, and virus causes accounted for 26.5%, and 42.9% of submissions, respectively; co-infection of viral and fungal or oomycete pathogens were detected from 6.1% of submissions between 2019 and 2020. BCTV, a curtovirus, and hop latent viroid (HLVd) were the predominant pathogens detected from field and indoor grown hemp. Worland-like strains of BCTV represented 93% of all curtovirus detections. Eighty percent of HLVd detections occurred from plants that originated from indoor growing facilities. Based on BCTV vector, beet leafhopper, prevalence, field-grown hemp in western production regions may be affected by curly top and increasing hemp acreage in the landscape may have potential implications on other crops affected by curtoviruses. Virus and virus-like diseases could be a limiting factor for hemp production in some regions of the United States.

Plant Disease ◽  
2010 ◽  
Vol 94 (3) ◽  
pp. 381-381 ◽  
Author(s):  
R. L. Hirsch ◽  
D. O. TeBeest ◽  
B. H. Bluhm ◽  
C. P. West

In May 2007, switchgrass (Panicum virgatum L.) cv. Alamo and a breeding line, OSU-NSL 2001-1, were planted at the Arkansas Agricultural Research and Extension Center, Fayetteville. In August 2008, a high incidence of dark brown-to-black rectangular foliar lesions delineated by major veins was observed throughout plots of both lines. Lesions covered 25% to nearly 100% of total leaf tissue. Similar symptoms were also observed on unknown switchgrass cultivars in Benton County in northwest Arkansas and in St. Francis County in east-central Arkansas, suggesting that the disease was widely distributed throughout the state. The pathogen produced epiphyllous and adaxial masses of dark brown-to-black telia from erumpent fissures on leaf surfaces. Dark brown teliospores were observed under magnification and were two-celled, oblong to ellipsoid, and 33 ± 3.5 μm long with an apical cell width of 17.5 ± 2.7 μm and basal cell width of 16.2 ± 2.8 μm (reported as mean ± standard deviation, n = 25). Pedicles were colorless to light brown and measured 25.4 ± 9.2 μm (n = 25). In June 2009, at the Fayetteville Research and Extension Center, several second-year stands of switchgrass developed amphigenous and adaxial foliar lesions containing urediniospores. The uredia were globose and finely echinulate, measuring 23.1 ± 2.2 μm (n = 25) with brown cell walls. Teliospore and urediniospore morphology from all collections was consistent with Puccinia emaculata Schw. (2). Genomic DNA was extracted from a representative infected leaf of cv. Alamo, collected in Fayetteville, AR in June 2009, and amplified by PCR with primer sets PRITS1F (3) and ITS4B (1), which amplified an 803-bp fragment of rDNA encoding the first internal transcribed spacer (ITS1), 5.8S subunit, and second internal transcribed spacer (ITS2). The fragment was cloned into pGEM T Easy (Promega Corp, Madison, WI) and sequenced. A BLAST search of GenBank revealed that the fragment was most similar to the rDNA of P. emaculata (GenBank Accession No. EU915294.1; 755 of 758 bases matching; 99% identity) previously reported as a pathogen on switchgrass in Tennessee (3). The incidence and severity of rust on the widely planted switchgrass cv. Alamo is considerable cause for concern as efforts are made to increase acreage and production. Climatic conditions in St. Francis County are generally consistent with locations in Tennessee where switchgrass rust was previously reported (3). However, northwest Arkansas represents the eastern edge of the southwestern United States, suggesting that P. emaculata may affect switchgrass in geographically diverse areas of the United States. To our knowledge, this study represents the first report of rust on switchgrass in Arkansas. Managing this disease will be an important consideration for large-scale switchgrass cultivation in the state. References: (1) M. Gardes and T. D. Bruns. Mol. Ecol. 2:113, 1993. (2) P. Ramachar and G. Cummins. Mycopathol. Mycol. Appl. 25:7, 1965. (3) J. Zale et al. Plant. Dis. 92:1710, 2008.


Plant Disease ◽  
2003 ◽  
Vol 87 (3) ◽  
pp. 313-313 ◽  
Author(s):  
C. X. Hong ◽  
T. J. Banko

Disease samples of Gaillardia × grandiflora cvs. Goblin and Baby Cole were received at the Hampton Roads Agricultural Research and Extension Center in Virginia Beach in early April 2002. Samples were from a nursery in eastern Virginia, and most diseased plants had several to more than a dozen, round, flat, white to tan spots with indistinct margins up to 1 cm in diameter on their leaves. The spots later turned brown and necrotic, followed by necrosis of the entire leaf. Leaves of ‘Baby Cole’ were beginning to wilt and were more spotted than those of ‘Goblin’. Fungal fruiting bodies were not observed on the surface of diseased leaves. However, microscopic examination of internal leaf tissues revealed masses of round, double-walled, pale green-to-yellow spores approximately 12 μm in diameter and typical of the ustilospores of Entyloma polysporum (2,3). Inoculum for pathogenicity tests was prepared by blending 10 diseased leaves in 200 ml of sterile distilled water (SDW) for 2 min in a blender at low speed. The spore suspension was adjusted to 5 × 105 spores per ml with SDW. Healthy ‘Goblin’ gaillardia plants were obtained from a nursery where smut symptoms had never been seen. Four plants in one-gallon containers were inoculated by spraying them to runoff with the spore suspension. Four control plants were sprayed with SDW only. All plants were maintained in a greenhouse (15 to 35°C) and covered with a clean polyethylene plastic sheet overnight (14 h) to maintain high humidity and separated to avoid potential cross contamination. Inoculated and uninoculated plants were hand-watered separately, with application of water to the foliage to enhance spread of the disease. Typical white smut symptoms were observed on inoculated plants 2 weeks after inoculation, and numerous spores of E. polysporum were observed in the diseased tissues. No disease symptoms were seen on control plants. White smut has been reported on gaillardia in a few other states (1), but to our knowledge, this is the first report of the disease on gaillardia in Virginia. Growers at the affected nursery reported observing white smut symptoms on gaillardia in previous years, but in the spring of 2002, almost the entire gaillardia crop was destroyed. The disease has not been seen on gaillardia in any other nurseries, but it could have significant impact on production if it spreads. References: (1) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989. (2) W. Fischer. Manual of the North American Smut Fungi. Ronald Press, New York, 1953. (3) D. B. O. Savile. Can. J. Res. 25(C):109,1947.


2001 ◽  
Vol 11 (3) ◽  
pp. 392-396
Author(s):  
H. Brent Pemberton ◽  
William E. Roberson

The East Texas Bedding Plant Pack and Garden Performance Trials began several years ago at the Texas A&M University Agricultural Research and Extension Center at Overton (Overton Center) with the goal of providing information on greenhouse and field performance of bedding plant varieties to the local bedding plant industry and consumers of these products. The program began with local trials that have now expanded in scope with the Smith County Master Gardeners Association playing an integral role in performing the trials. Entries are received from most of the major ornamental seed companies doing business in the United States giving the regional industry access to the only comprehensive greenhouse performance trials in this part of the country. Performance evaluation data is important to this industry since it has a wholesale value of over $500 million in the northeast Texas region, of which over $100 million is bedding plant production. The field performance trials are now replicated at the Overton Center, the Dallas Arboretum and Botanical Garden (Dallas Arboretum) and the Texas A&M University Agricultural Research and Extension Center at Dallas (Dallas Center), giving over 5 million consumers in the northeast Texas region the opportunity to see how promising new plants from all over the world perform in the local climate. Plants that grow well in this climate have the potential to reduce inputs needed for production and use in the home or commercial landscape. Many of the top performing varieties from the bedding plant trials are also chosen to be part of the Coordinated Education and Marketing Assistance Program (CEMAP), a statewide testing program headquartered at the Dallas Center in which entries vie for designation as Texas Superstar plants. The comprehensive benefit of the East Texas Bedding Plant Pack and Garden Performance Trials is the link between the rural bedding plant producers and the urban consumers which serves as a basis for improving the quality of life for the citizens of Texas.


HortScience ◽  
2021 ◽  
pp. 1-11
Author(s):  
Bao-Zhong Yuan ◽  
Zhi-Long Bie ◽  
Jie Sun

Cucumber (Cucumis sativus L.) is an economically important vegetable crop that is cultivated worldwide. The current study aimed to identify and analyze the 2030 articles and review article about cucumber research from the horticulture category of the VOS viewer Web of Science. Bibliometric data were analyzed by bibliometric science mapping and visualization tools. Articles mainly written in English (1884; 92.81%) were from 5630 authors, 80 countries or territories, and 1094 organizations; they were published in 46 journals and book series. The top five core journals are Scientia Horticulturae (337; 16.60%), HortScience (265; 13.05%), Journal of the American Society for Horticultural Science (239; 11.77%), European Journal of Plant Pathology (195; 9.61%), and Horticulture Journal (Journal of the Japanese Society for Horticultural Science) (157; 7.73%). These journals each published more than 157 articles. The top five countries and regions were the United States, People’s Republic of China, Japan, South Korea, and India. The top five organizations were the University of Wisconsin, North Carolina State University, U.S. Department of Agriculture–Agricultural Research Service, Michigan State University, and Nanjing Agricultural University. The top five authors are Todd C. Wehner (Wehner, TC), Jack E. Staub (Staub, JE), Yiqun Weng, R.L. Lower, and S. Tachibana; each published more than 24 articles. All keywords used for cucumber research in the horticulture category were separated into eight clusters for different research topics. Visualizations offer exploratory information regarding the current state in a scientific field or discipline as well as indicate possible developments in the future. This review could be a valuable guide for designing future studies.


Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 91
Author(s):  
R. Dan Seale ◽  
Rubin Shmulsky ◽  
Frederico Jose Nistal Franca

This review primarily describes nondestructive evaluation (NDE) work at Mississippi State University during the 2005–2020 time interval. Overall, NDE is becoming increasingly important as a means of maximizing and optimizing the value (economic, engineering, utilitarian, etc.) of every tree that comes from the forest. For the most part, it focuses on southern pine structural lumber, but other species such as red pine, spruce, Douglas fir, red oak, and white oak and other products such as engineered composites, mass timber, non-structural lumber, and others are included where appropriate. Much of the work has been completed in conjunction with the U.S. Department of Agriculture, Forest Service, Forest Products Laboratory as well as the Agricultural Research Service with the overall intent of improving lumber and wood products standards and valuation. To increase the future impacts and adoption of this NDE-related work, wherever possible graduate students have contributed to the research. As such, a stream of trained professionals is a secondary output of these works though it is not specifically detailed herein.


2021 ◽  
Vol 22 (8) ◽  
pp. 4224
Author(s):  
Urban Kunej ◽  
Jernej Jakše ◽  
Sebastjan Radišek ◽  
Nataša Štajner

RNA interference is an evolutionary conserved mechanism by which organisms regulate the expression of genes in a sequence-specific manner to modulate defense responses against various abiotic or biotic stresses. Hops are grown for their use in brewing and, in recent years, for the pharmaceutical industry. Hop production is threatened by many phytopathogens, of which Verticillium, the causal agent of Verticillium wilt, is a major contributor to yield losses. In the present study, we performed identification, characterization, phylogenetic, and expression analyses of three Argonaute, two Dicer-like, and two RNA-dependent RNA polymerase genes in the susceptible hop cultivar Celeia and the resistant cultivar Wye Target after infection with Verticillium nonalfalfae. Phylogeny results showed clustering of hop RNAi proteins with their orthologues from the closely related species Cannabis sativa, Morus notabilis and Ziziphus jujuba which form a common cluster with species of the Rosaceae family. Expression analysis revealed downregulation of argonaute 2 in both cultivars on the third day post-inoculation, which may result in reduced AGO2-siRNA-mediated posttranscriptional gene silencing. Both cultivars may also repress ta-siRNA biogenesis at different dpi, as we observed downregulation of argonaute 7 in the susceptible cultivar on day 1 and downregulation of RDR6 in the resistant cultivar on day 3 after inoculation.


1993 ◽  
Vol 67 (1) ◽  
pp. 151-151
Author(s):  
R. William Orr ◽  
Richard H. Fluegeman

In 1990 (Fluegeman and Orr) the writers published a short study on known North American cyclocystoids. This enigmatic group is best represented in the United States Devonian by only two specimens, both illustrated in the 1990 report. Previously, the Cortland, New York, specimen initially described by Heaslip (1969) was housed at State University College at Cortland, New York, and the Logansport, Indiana, specimen was housed at Ball State University, Muncie, Indiana. Both institutions recognize the importance of permanently placing these rare specimens in a proper paleontologic repository with other cyclocystoids. Therefore, these two specimens have been transferred to the curated paleontologic collection at the University of Cincinnati Geological Museum where they can be readily studied by future workers in association with a good assemblage of Ordovician specimens of the Cyclocystoidea.


2021 ◽  
Vol 37 (2) ◽  
pp. 119-136
Author(s):  
Rick Mitchell

As today’s catastrophic Covid-19 pandemic exacerbates ongoing crises, including systemic racism, rising ethno-nationalism, and fossil-fuelled climate change, the neoliberal world that we inhabit is becoming increasingly hostile, particularly for the most vulnerable. Even in the United States, as armed white-supremacist, pro-Trump forces face off against protesters seeking justice for African Americans, the hostility is increasingly palpable, and often frightening. Yet as millions of Black Lives Matter protesters demonstrated after the brutal police killing of George Floyd, the current, intersecting crises – worsened by Trump’s criminalization of anti-racism protesters and his dismissal of science – demand a serious, engaged, response from activists as well as artists. The title of this article is meant to evoke not only the state of the unusually cruel moment through which we are living, but also the very different approaches to performance of both Brecht and Artaud, whose ideas, along with those of others – including Benjamin, Butler, Latour, Mbembe, and Césaire – inform the radical, open-ended, post-pandemic theatre practice proposed in this essay. A critically acclaimed dramatist as well as Professor of English and Playwriting at California State University, Northridge, Mitchell’s published volumes of plays include Disaster Capitalism; or Money Can’t Buy You Love: Three Plays; Brecht in L.A.; and Ventriloquist: Two Plays and Ventriloquial Miscellany. He is the editor of Experimental O’Neill, and is currently at work on a series of post-pandemic plays.


2016 ◽  
Vol 26 (6) ◽  
pp. 862-868 ◽  
Author(s):  
Kimberly A. Williams ◽  
Chad T. Miller ◽  
Ward Upham

In recent years, many horticulture departments around the United States have been concerned with recruiting and retaining an adequate number of students. One potential recruitment opportunity is the horticulture Future Farmers of America (FFA) Career Development Events (CDEs). For the time period of 1999 to 2012 (14 years), 1462 students participated in the annual state-level horticulture contests, comprising floriculture and nursery/landscape CDEs, held at Kansas State University (KSU). Using the rosters from these two CDEs, we referenced the university’s student information database to determine whether the high school students who participated as FFA horticulture CDE contestants ultimately matriculated to KSU. Fifty-two percent of former FFA horticulture CDE participants were accepted to KSU and 32% matriculated. Of these, 58% enrolled in the College of Agriculture and 19% majored in horticulture. Therefore, 3.5% of total horticulture CDE participants majored in horticulture at KSU. Students who participated in more than one horticulture CDE over time were more likely to major in horticulture at KSU compared with students who competed only once. Thirty-nine percent of students who participated in both horticulture CDEs pursued a baccalaureate program in horticulture. These two student characteristics could be used as indicator data points to target recruitment of future horticulture students. Data about the high school programs that generated contest participants were also summarized. Exceling in the CDE contests was not an indicator CDE participants would pursue a baccalaureate degree in horticulture. These analyses suggest FFA CDEs have some potential to optimize student recruitment efforts.


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