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Sydney E Everhart - One of the best experts on this subject based on the ideXlab platform.
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differential aggressiveness of sclerotinia sclerotiorum isolates from north and south america and partial host resistance in brazilian soyBean and Dry Bean cultivars
Tropical Plant Pathology, 2019Co-Authors: James R. Steadman, Thomas J J Miorini, Zhian N Kamvar, Rebecca Higgins, Carlos Gilberto Raetano, Sydney E EverhartAbstract:White mold (or Sclerotinia stem rot), caused by Sclerotinia sclerotiorum, is a yield-reducing disease of great importance to both Dry Bean and soyBean crops in the Americas. Characterization of both the physiological resistance in commercial cultivars to white mold disease and the range of aggressiveness among S. sclerotiorum isolates collected from locations where these cultivars are to be deployed provides useful information for breeding and management. In this study, aggressiveness was characterized for a collection of 82 isolates originating North and South America and the reaction of 23 Dry Bean and 11 soyBean cultivars from Brazil was evaluated. The detached leaf bioassay (DLB) was used to assess aggressiveness of 63 isolates on U.S. soyBean cultivar Dassel and 25 isolates on Brazilian Dry Bean cultivar IAC Alvorada. The straw test (ST) was used to evaluate the aggressiveness of 32 isolates on U.S. Dry Bean cultivar G122 and 26 isolates on Brazilian cultivar IAC Alvorada. Results of the DLB test showed that the isolates were in general more aggressive towards Bean IAC Alvorada (\( \overline{x} \) = 14.26 cm2) than on soyBean Dassel (\( \overline{x} \) = 9.20 cm2). ST ratings classified 24 26 isolates inoculated on Dry Bean IAC Alvorada as highly aggressive (\( \overline{x} \) = 8.0), whereas no isolates were classified as highly aggressive on Dry Bean G122 (\( \overline{x} \) = 5.1). When the isolates were compared for aggressiveness, some of them were consistently rated in the top 10, regardless of the evaluation method or plant host used. Based on results of both inoculation methods, IAC Diplomata and IPR Tangara were the most resistant to S. sclerotiorum among 23 Brazilian Dry Bean cultivars. In soyBean, M5410 and M6410 were classified as the most resistant. Collectively, results of this study contribute new knowledge of variation in aggressiveness in the pathogen population and of cultivars that may have partial resistance, warranting further investigation.
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population structure and phenotypic variation of sclerotinia sclerotiorum from Dry Bean phaseolus vulgaris in the united states
PeerJ, 2017Co-Authors: Zhian N Kamvar, James R. Steadman, Sajeewa B Amaradasa, Rachana Jhala, Serena Mccoy, Sydney E EverhartAbstract:The ascomycete pathogen Sclerotinia sclerotiorum is a necrotrophic pathogen on over 400 known host plants, and is the causal agent of white mold on Dry Bean. Currently, there are no known cultivars of Dry Bean with complete resistance to white mold. For more than 20 years, Bean breeders have been using white mold screening nurseries (wmn) with natural populations of S. sclerotiorum to screen new cultivars for resistance. It is thus important to know if the genetic diversity in populations of S. sclerotiorum within these nurseries (a) reflect the genetic diversity of the populations in the surrounding region and (b) are stable over time. Furthermore, previous studies have investigated the correlation between mycelial compatibility groups (MCG) and multilocus haplotypes (MLH), but none have formally tested these patterns. We genotyped 366 isolates of S. sclerotiorum from producer fields and wmn surveyed over 10 years in 2003-2012 representing 11 states in the United States of America, Australia, France, and Mexico at 11 microsatellite loci resulting in 165 MLHs. Populations were loosely structured over space and time based on analysis of molecular variance and discriminant analysis of principal components, but not by cultivar, aggressiveness, or field source. Of all the regions tested, only Mexico (n = 18) shared no MLHs with any other region. Using a bipartite network-based approach, we found no evidence that the MCGs accurately represent MLHs. Our study suggests that breeders should continue to test Dry Bean lines in several wmn across the United States to account for both the phenotypic and genotypic variation that exists across regions.
James R. Steadman - One of the best experts on this subject based on the ideXlab platform.
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differential aggressiveness of sclerotinia sclerotiorum isolates from north and south america and partial host resistance in brazilian soyBean and Dry Bean cultivars
Tropical Plant Pathology, 2019Co-Authors: James R. Steadman, Thomas J J Miorini, Zhian N Kamvar, Rebecca Higgins, Carlos Gilberto Raetano, Sydney E EverhartAbstract:White mold (or Sclerotinia stem rot), caused by Sclerotinia sclerotiorum, is a yield-reducing disease of great importance to both Dry Bean and soyBean crops in the Americas. Characterization of both the physiological resistance in commercial cultivars to white mold disease and the range of aggressiveness among S. sclerotiorum isolates collected from locations where these cultivars are to be deployed provides useful information for breeding and management. In this study, aggressiveness was characterized for a collection of 82 isolates originating North and South America and the reaction of 23 Dry Bean and 11 soyBean cultivars from Brazil was evaluated. The detached leaf bioassay (DLB) was used to assess aggressiveness of 63 isolates on U.S. soyBean cultivar Dassel and 25 isolates on Brazilian Dry Bean cultivar IAC Alvorada. The straw test (ST) was used to evaluate the aggressiveness of 32 isolates on U.S. Dry Bean cultivar G122 and 26 isolates on Brazilian cultivar IAC Alvorada. Results of the DLB test showed that the isolates were in general more aggressive towards Bean IAC Alvorada (\( \overline{x} \) = 14.26 cm2) than on soyBean Dassel (\( \overline{x} \) = 9.20 cm2). ST ratings classified 24 26 isolates inoculated on Dry Bean IAC Alvorada as highly aggressive (\( \overline{x} \) = 8.0), whereas no isolates were classified as highly aggressive on Dry Bean G122 (\( \overline{x} \) = 5.1). When the isolates were compared for aggressiveness, some of them were consistently rated in the top 10, regardless of the evaluation method or plant host used. Based on results of both inoculation methods, IAC Diplomata and IPR Tangara were the most resistant to S. sclerotiorum among 23 Brazilian Dry Bean cultivars. In soyBean, M5410 and M6410 were classified as the most resistant. Collectively, results of this study contribute new knowledge of variation in aggressiveness in the pathogen population and of cultivars that may have partial resistance, warranting further investigation.
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population structure and phenotypic variation of sclerotinia sclerotiorum from Dry Bean phaseolus vulgaris in the united states
PeerJ, 2017Co-Authors: Zhian N Kamvar, James R. Steadman, Sajeewa B Amaradasa, Rachana Jhala, Serena Mccoy, Sydney E EverhartAbstract:The ascomycete pathogen Sclerotinia sclerotiorum is a necrotrophic pathogen on over 400 known host plants, and is the causal agent of white mold on Dry Bean. Currently, there are no known cultivars of Dry Bean with complete resistance to white mold. For more than 20 years, Bean breeders have been using white mold screening nurseries (wmn) with natural populations of S. sclerotiorum to screen new cultivars for resistance. It is thus important to know if the genetic diversity in populations of S. sclerotiorum within these nurseries (a) reflect the genetic diversity of the populations in the surrounding region and (b) are stable over time. Furthermore, previous studies have investigated the correlation between mycelial compatibility groups (MCG) and multilocus haplotypes (MLH), but none have formally tested these patterns. We genotyped 366 isolates of S. sclerotiorum from producer fields and wmn surveyed over 10 years in 2003-2012 representing 11 states in the United States of America, Australia, France, and Mexico at 11 microsatellite loci resulting in 165 MLHs. Populations were loosely structured over space and time based on analysis of molecular variance and discriminant analysis of principal components, but not by cultivar, aggressiveness, or field source. Of all the regions tested, only Mexico (n = 18) shared no MLHs with any other region. Using a bipartite network-based approach, we found no evidence that the MCGs accurately represent MLHs. Our study suggests that breeders should continue to test Dry Bean lines in several wmn across the United States to account for both the phenotypic and genotypic variation that exists across regions.
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Evaluation of soyBean, Dry Bean, and sunflower for resistance to Sclerotinia sclerotiorum
Crop Science, 2004Co-Authors: Tri D. Vuong, James R. Steadman, D. D. Hoffman, Brian W. Diers, Jerry F. Miller, Glen L. HartmanAbstract:Many inoculation methods have been used to evaluate resistance of different crops to Sclerotinia sclerotiorum (Lib.) de Bary. Only a few of these methods have been used to evaluate more than one crop. This study compared disease evaluations of soyBean [Glycine max (L.) Merr.], Dry Bean (Phaseolus vulgaris L.), and sunflower (Helianthus annuus L.) inoculated in the greenhouse (cut stem inoculation method) to field evaluations. In one experiment, stems of two soyBean cultivars, Williams 82 (susceptible) and NKS19-90 (partially resistant), were severed and inoculated with a colonized mycelial plug of S. sclerotiorum placed on top of the plant at the cut point of the stem. Stem lesion lengths on these two cultivars were used to determine what effect plant age and post-infection temperature had on disease development. There was a significant (P < 0.05) difference in lesion lengths between inoculated 5-wk-old plants compared with 6- or 7-wk-old plants within each cultivar. At different post-infection temperatures, lesions developed at 25 degrees C but not at 30 degrees C. In another experiment, disease rating of 15 soyBean cultivars evaluated in the greenhouse and field had significant (P < 0.05) correlation coefficients from 0.53 to 0.79. In addition to soyBean, two experiments were completed on Dry Bean and sunflower. There were significant (P < 0.05) differences in lesion lengths among 14 genotypes within Dry Bean and sunflower. The correlation between greenhouse and field evaluations of Dry Bean and sunflower were 0.74 and 0.50 (P < 0.05), respectively. In summary, disease assessments from the cut stem inoculation compared favorably with disease assessments in the field for soyBean, Dry Bean, and sunflower.
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Evaluation of Resistance Screening Methods for Sclerotinia Stem Rot of SoyBean and Dry Bean
Plant disease, 2003Co-Authors: Linda S. Kull, James R. Steadman, Tri D. Vuong, Kris S. Powers, Kent M. Eskridge, Glen L. HartmanAbstract:Three methods to identify levels of resistance to Sclerotinia sclerotiorum in soyBean (Glycine max) and Dry Bean (Phaseolus vulgaris) were compared using multiple data analyses. The three methods were mycelial plug inoculations of cotyledons, cut stems, and detached leaves. Six S. sclerotiorum isolates of known relative aggressiveness were inoculated on each of three soyBean and Dry Bean cultivars with varied response to S. sclerotiorum. For soyBean, all three inoculation methods accurately identified isolate aggressiveness irrespective of cultivar, but identification of susceptible and partially resistant soyBean cultivars was influenced by isolate. For Dry Bean, the cotyledon and cut stem methods accurately identified isolate aggressiveness, but identification of susceptible and partially resistant Dry Bean cultivars was influenced by isolate and inoculation method. The cut stem method had the smallest coefficient of variation and was more precise for detecting interactions. When considering root mean square residual error combined over species and experiments, coefficient of variation based on residual error, significance of isolate-by-cultivar interaction from ANOVA, rank correlation between pairs of methods, and sensitivity ratio for the three resistance screening methods under controlled environmental conditions, the cut stem method was statistically better than the cotyledon and detached leaf methods for evaluating resistance in soyBean and Dry Bean cultivars.
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`Weihing' Great Northern Disease-resistant Dry Bean
HortScience, 2000Co-Authors: Dermot P. Coyne, D. S. Nuland, Dale T. Lindgren, James R. Steadman, D.w. Smith, J.w. Gonzales, J. Schild, J. Reiser, Lisa Sutton, Clay CarlsonAbstract:Received for publication 14 June 1999. Accepted for publication 1 Aug. 1999. Published as Paper No. 12639, Journal Series, Nebraska Agricultural Research Division. The research was conducted under Projects 20-036 and 20-042. We acknowledge financial support for the development of this cultivar from the Nebraska Dry Bean Commission, Nebraska Dry Bean Growers Association, and the Title XII Bean/Cowpea (AID Contract No. DAN-1310G-SS-6008-00). We also appreciate technical advice and help from Dr. Anne Vidaver, Dr. Eric Kerr, Patricia Lambrecht, and Don Schaaf, Univ. of Nebraska Extension Center, Scottsbluff. This variety was named in recognition of Dr. John Weihing, former director of the Panhandle Research and Extension Center, Scottsbluff, Nebr. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact. Dept. of Horticulture. To whom reprint requests should be addressed (e-mail: dcoyne1@unl.edu). Panhandle Research and Extension Center, Scottsbluff. West Central Research and Extension Center, North Platte. Dept. of Plant Pathology. Dept. of Food Science and Technology. Cooperative Extension Division, Gering. ‘Weihing’ Great Northern Diseaseresistant Dry Bean
Sajeewa B Amaradasa - One of the best experts on this subject based on the ideXlab platform.
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population structure and phenotypic variation of sclerotinia sclerotiorum from Dry Bean phaseolus vulgaris in the united states
PeerJ, 2017Co-Authors: Zhian N Kamvar, James R. Steadman, Sajeewa B Amaradasa, Rachana Jhala, Serena Mccoy, Sydney E EverhartAbstract:The ascomycete pathogen Sclerotinia sclerotiorum is a necrotrophic pathogen on over 400 known host plants, and is the causal agent of white mold on Dry Bean. Currently, there are no known cultivars of Dry Bean with complete resistance to white mold. For more than 20 years, Bean breeders have been using white mold screening nurseries (wmn) with natural populations of S. sclerotiorum to screen new cultivars for resistance. It is thus important to know if the genetic diversity in populations of S. sclerotiorum within these nurseries (a) reflect the genetic diversity of the populations in the surrounding region and (b) are stable over time. Furthermore, previous studies have investigated the correlation between mycelial compatibility groups (MCG) and multilocus haplotypes (MLH), but none have formally tested these patterns. We genotyped 366 isolates of S. sclerotiorum from producer fields and wmn surveyed over 10 years in 2003-2012 representing 11 states in the United States of America, Australia, France, and Mexico at 11 microsatellite loci resulting in 165 MLHs. Populations were loosely structured over space and time based on analysis of molecular variance and discriminant analysis of principal components, but not by cultivar, aggressiveness, or field source. Of all the regions tested, only Mexico (n = 18) shared no MLHs with any other region. Using a bipartite network-based approach, we found no evidence that the MCGs accurately represent MLHs. Our study suggests that breeders should continue to test Dry Bean lines in several wmn across the United States to account for both the phenotypic and genotypic variation that exists across regions.
Suat Irmak - One of the best experts on this subject based on the ideXlab platform.
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deficit irrigation and surface residue cover effects on Dry Bean yield in season soil water content and irrigation water use efficiency in western nebraska high plains
Agricultural Water Management, 2018Co-Authors: Dean C Yonts, Amir Haghverdi, David L Reichert, Suat IrmakAbstract:Abstract Considering ground water pumping restrictions and unpredictable amount of water available for irrigation from year to year, Nebraska Panhandle producers are facing a challenge to reduce their irrigation water usage and practice deficit irrigation. Among irrigated crops in the region, Dry Bean (a major cash crop and critical to crop rotation systems) has relatively low water use and is capable to withstand periods of stress. Consequently, two experiments within six consecutive growing seasons (2010–2015) were conducted to determine the impacts of multiple irrigation scenarios (full irrigation, deficit irrigation, and rainfed) and two soil surface conditions (bare soil versus crop residue) on Dry Bean production, irrigation water use efficiency, and temporal soil water dynamic within the crop root zone. Dry Bean yield ranged from 0.41 to 4.07 Mg ha−1 during the six years of the study (2010–2015). The results (2012–2015) indicated that reducing irrigation water by 25% on average increased irrigation water use efficiency (IWUE) by 26% and only caused 6% yield reduction in relative to the full irrigation treatment scenario. However, applying only 50% crop evapotranspiration requirement (ETc) resulted in significant yield reduction (30% reduction on average) in 5 out of 6 years compared to the full irrigation treatment (p
Robert E Blackshaw - One of the best experts on this subject based on the ideXlab platform.
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Agronomic merits of cereal cover crops in Dry Bean production systems in western Canada
Crop Protection, 2008Co-Authors: Robert E BlackshawAbstract:Abstract Cover crops may have a valuable role to play in developing improved Dry Bean production systems. A field experiment was conducted to determine the agronomic benefits of including various fall-seeded and spring-seeded cereal cover crops with and without in-crop herbicides in Dry Bean. Main plot treatments included fall-seeded winter rye, barley, oat, and spring rye; spring-seeded barley, oat, and spring rye; and a no-cover crop control. Subplot treatments consisted of in-crop sethoxydim/bentazon and an untreated control. Fall-seeded cover crops were often superior to spring-seeded cover crops in terms of providing sufficient ground cover to reduce the risk of soil erosion and reducing weed emergence and growth. Among the fall-seeded cover crops, winter rye provided the greatest ground cover and often resulted in the greatest weed suppression. Dry Bean density was not affected by any of the cover crops, but fall-seeded cover crops delayed emergence by up to 5 days and delayed maturity by up to 4 days. Cover crop effects on Dry Bean yield were most evident in the absence of in-crop herbicides, where fall-seeded cover crops increased Dry Bean yield by 20–90%. Cover crops also increased Dry Bean yield in 2 of 3 years when in-crop herbicides were used but yield increases were much smaller, ranging from 5% to 13%. These yield increases occurred with fall-seed cover crops that aided in weed management but also with spring-seeded cover crops where weed suppression was not evident, suggesting that cover crops provided additional benefits beyond weed management. Information gained in this study will be utilized to advise farmers on the most suitable use of cover crops in sustainable Dry Bean production systems.
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Integration of Conservation Tillage and Herbicides for Sustainable Dry Bean Production
Weed Technology, 2008Co-Authors: Robert E Blackshaw, Louis J MolnarAbstract:Development of conservation tillage practices for Dry Bean has lagged behind that of many other crops. A field study was conducted to determine the effects of various crop residues and herbicide treatments on weed management and Dry Bean yield within a zero-tillage system. Main plot treatments included wheat stubble, canola stubble, fall-seeded winter rye, fall-seeded spring rye, and a no-cover control. Subplot treatments included various preplant and POST herbicides. Wheat stubble, canola stubble, and winter rye residue provided sufficient ground cover to prevent soil erosion, and they effectively reduced weed density compared with the no-cover control in all years. Fall-seeded spring rye provided only partial soil-erosion protection and reduced weed density in only 1 of 3 yr. Dry Bean emergence was 3 to 5 d slower in the crop residue treatments compared with the no-cover control, but crop density was not adversely affected. However, winter rye residue delayed Dry Bean maturity by 2 to 6 d. Fall-applied ...
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Dry Bean production in zero and conventional tillage
Agronomy Journal, 2007Co-Authors: Robert E Blackshaw, Louis J Molnar, G W Clayton, Neil K Harker, T EntzAbstract:Adoption of zero tillage production practices for Dry Bean (Phaseolus vulgaris L.) has lagged behind that of many other crops. A field experiment was conducted at two locations on the Canadian prairies to determine the response of Dry Bean planted into various crop stubbles in conventional and zero tillage. Dry Bean emergence was delayed in one of six site years with zero tillage (ZT) compared with conventional tillage (CT) but maturity date was not affected. Dry Bean density was never lower with ZT compared with CT and was higher in a few instances. There were no differences in insect or disease infestations between the two tillage treatments. Weed densities were slightly greater with ZT compared with CT but were well controlled with in-crop applications of sethoxydim and bentazon. Flax (Linum usitatissimum L.) was the only previous crop to negatively affect Dry Bean yield as volunteer flax was not adequately controlled with bentazon. Over all previous crop stubbles and years, Dry Bean yield was similar in both tillage systems. Dry Bean yielded 2060 and 2110 kg ha -1 , and 1600 and 1710 kg ha -1 with CT and ZT at Lethbridge and Lacombe, Alberta, respectively. These results indicate that there is potential for successful production of Dry Bean within ZT cropping systems.
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integration of cropping practices and herbicides improves weed management in Dry Bean phaseolus vulgaris 1
Weed Technology, 2000Co-Authors: Robert E Blackshaw, Louis J Molnar, Henning H Muendel, Gilles SaindonAbstract:Abstract: A field study was conducted to determine the combined effects of row spacing, plant density, and herbicides on weed management and Dry Bean (Phaseolus vulgaris) yield. In weed-free Dry Bean, a reduction in row spacing from 69 to 23 cm increased yield by 19% and an increase in density from 20 to 50 plants/m2 increased yield by 17%. In the presence of weeds, narrow rows and high plant densities increased Dry Bean yield, but without herbicides, yields remained low. However, when combined with herbicides, narrow-row and high-density production practices resulted in better weed control and higher Dry Bean yield than that attained in a wide-row and low-density production system. Herbicide combinations, often at reduced rates, controlled weeds as well or better than the full rate of any individual herbicide. Ethalfluralin applied preplant incorporated followed by reduced rates of imazethapyr or bentazon postemergence (POST) consistently controlled weeds. Imazamox exhibited the potential to provide a to...
