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Strausbaugh, C.A., Panella, L.W. 2016. Beet curly top resistance in USDA-ARS plant introduction lines, 2015
Get PDFCurly top caused by Beet curly top virus (BCTV) is a widespread disease problem vectored by the beet leafhopper in semiarid sugar beet production areas. Host resistance is the primary defense against this problem, but resistance in commercial cultivars is only low to intermediate. In order to identify novel sources of curly top resistance, thirty-one Plant Introduction (PI) Lines were screened in a disease nursery in 2015. The lines were arranged in a randomized complete block design with three replications. A curly top epiphytotic was created by releasing approximately 6 viruliferous beet leafhoppers per plant at the four- to six-leaf growth stage on 24 Jun. Foliar symptoms were evaluated on 13 and 20 Jul using a scale of 0-9 (0 = healthy and 9 = dead) in a continuous manner. Curly top symptom development was uniform and no other disease problems were evident in the plot area. The disease pressure in the test was moderately severe with good symptom development in the susceptible check. Seven of the PIs were not significantly different from the resistant checks based on the overall visual symptom rating. These promising lines will be retested and, if resistance is confirmed, they will be incorporated into the USDA-ARS sugar beet germplasm improvement program as potentially novel sources of resistance to BCTV
Registration of sugar beet doubled haploid line KDH13 with resistance to beet curly top
Get PDFKDH13 is a sugar beet (Beta vulgaris L. ssp vulgaris) doubled haploid line (PI 663862) released as a genetic stock by USDA-ARS in cooperation with the Beet Sugar Development Foundation, Denver, CO. KDH13 is resistant to beet curly top (BCT) caused by Beet curly top virus which is transmitted by the beet leafhopper (Circulifer tenellus Baker). KDH13 was extracted from the BCT resistant C762-17 (PI 560130) parental line that segregates for BCT resistance and genetic male sterility. Intensive phenotypic screening was used for selecting plants from C762-17 that showed no symptoms under fully controlled infection conditions in the greenhouse. Seed from a single plant was used as a donor of floral buds for isolation of unfertilized ovaries to regenerate KDH13 via gynogenesis, and was confirmed a diploid by flow cytometry. The whole genome for this line was sequenced via next generation sequencing and its assembly was designated BvvSeq-1. The assembly was used to identify a large set of single nucleotide polymorphic markers (SNP) aligned to a BCT susceptible line (KWS2320) genome assembly. Homozygosity of KHD13 was confirmed using SNPs. It is a monogerm, self- fertile, and requires at least 90 days of vernalization for bolting. KDH13 outperformed BCT resistant commercial checks in greenhouse and field screening experiments. This line was used in crosses with susceptible parents and proved to be suitable as a donor parent for curly top resistance genes
Fall and spring tillage effects on sugarbeet production
Get PDFThe ability to vary primary tillage timing between fall and spring for sugarbeet production could benefit producers by providing flexibility for when field work occurs and may allow earlier planting in the spring. This study was conducted to evaluate the effects of strip and conventional tillage conducted in the spring and fall under various N supply levels on sugarbeet production in the northwest U.S. The treatments included tillage time (fall and spring), tillage system (moldboard plow, chisel plow and strip tillage), and N supply (5 levels including a control). The study was conducted in Kimberly, ID in 2008 and 2009 on a Portneuf silt loam. Within each year and tillage type, estimated recoverable sucrose and root yields were not different between fall and spring tillage timings. These data suggest that sugarbeet growers in the northwest U.S. have flexibility in timing their tillage practices across various tillage systems
Effect of phosphorus placement methods and rates on sugarbeet production under strip tillage in southern Idaho
Get PDFStrip tillage usage is increasing in the sugarbeet production systems of the Pacific Northwest and research data to guide phosphorus placement options and application rate for those options need to be acquired. The effects of phosphorus application method (surface and subsurface band) and phosphorus application rate (0 to 230 kg P2O5 per ha) were evaluated in 2009 and 2010 on sugarbeet grown under strip tillage at the USDA-ARS Northwest Irrigation & Soils Research Laboratory at Kimberly, ID. The soil at the study sites was a Portneuf silt loam (coarse-silty mixed superactive, mesic Durixerollic Xeric Haplocalcids) that had low bicarbonate extractable phosphorus concentrations of 3.7 and 6.0 mg per kg in 2009 and 2010, respectively. In general, yields did not differ between phosphorus fertilizer application methods. Yields increased as phosphorus rate increased and were not maximized at the highest application rate applied in this study (greater than 230 kg P2O5 per ha). The harvested roots removed an equivalent of 14.3 percent of the applied fertilizer P and the entire plant extracted an equivalent of 22.7 percent of the applied fertilizer phosphorus. Research does not provide evidence that the current University of Idaho and Amalgamated Sugar Company phosphorus fertilizer recommendations should be changed for strip tillage regardless of the application methods used in this study
Path analyses of grain P, Zn, Cu, Fe, and Ni in a biosolids-amended dryland wheat agroecosystem
Get PDFBiosolids land application is an effective means of recycling plant nutrients and is the preferred method of biosolids reuse by the US Environmental Protection Agency. One issue concerning biosolids application is the extent of the contribution of biosolids-borne plant nutrients to the overall crop concentration and uptake or removal of these nutrients. We hypothesized that the nutrients associated with the biosolids would have the greatest impact on wheat (Triticum aestivum, L.) grain phosphorus, zinc, copper, iron, and nickel concentrations and uptake at two dryland agroecosystem sites from 1993-2014. We employed path analyses in combination with multiple linear regressions to differentiate the direct and indirect effects of soil ammonium biocarbonate-diethylenetriaminepentaacetic acid, cumulative biosolids nutrient additions, soil pH, and organic carbon. Biosolids rates applied in a wheat-fallow rotation were 0, 2.24, 4.48, 6.72, 8.96, and 11.2 Mg/ha from 1993-2014. Biosolids additions had the greatest positive direct impact on grain iron concentrations and on grain phosphorus, zinc, iron, and nickel uptake (removal). Soil ammonium biocarbonate-diethylenetriaminepentaacetic acid and pH directly and indirectly affected some grain concentrations and cumulative uptake, but no consistent trends were noted. Soil organic carbon did not have any direct or indirect impacts. This approach allowed differentiation between causation and simple correlation effects for the effects of biosolids-borne nutrients on wheat phosphorus, zinc, copper, iron, and nickel concentrations and cumulative uptake
Commercial sugar beet cultivars evaluated for rhizomania resistance and storability in Idaho, 2015
Get PDFRhizomania caused by Beet necrotic yellow vein virus (BNYVV) and storage losses are serious sugar beet production problems. To identify sugar beet cultivars with resistance to BNYVV and evaluate storability, 28 commercial cultivars were screened by growing them in a sugar beet field infested with BNYVV in Kimberly, ID during the 2015 growing season in a randomized complete block design with 6 replications. At harvest on 28-29 September 2015, roots were dug and evaluated for symptoms of rhizomania and also placed in an indoor commercial sugar beet storage building. After 136 days in storage, samples were evaluated for surface rot, weight loss, and sucrose loss. Surface root rot ranged from 13 to 81%, weight loss ranged from 9.2 to 21.0%, sucrose losses ranged from 24 to 89%, and estimated recoverable sucrose ranged from 439 to 8,057 lb/A. Given these response ranges, selecting cultivars for rhizomania resistance and combining this resistance with storability will lead to considerable economic benefit for the sugar beet industry
Recovery of culturable of Escherichia coli O157:H7 during operation of a liquid-based bioaerosol sampler
Get PDFCollection fluids used in liquid-based bioaerosol samplers can influence the viability of microorganisms. In this study we determined the recovery efficiency of vegetative E. coli O157:H7 cells that were spiked into low viscosity evaporating collection fluids during operation of a BioSampler™ for up to 90 min at room temperature. The collection fluids tested were distilled (DI) water, phosphate-buffered saline (PBS) and osmoprotectants consisting of peptone and/or antifoam or betaine at 0.1% (w/w) in DI water. Using DI water, there was a rapid decline in the recovery of culturable E. coli, with only 11, 3, and 0% being recovered after 30, 60, and 90 min, respectively. Recoveries were substantially greater with use of PBS (53, 25, and 16%, respectively) but not as high as with use of the osmoprotectants. Peptone solutions, which are commonly used in liquid-based bioaerosol samplers, allowed for the recovery of 87% of the E. coli after 90 min. However, the control data indicate that some cellular growth did occur, which could be offsetting the recovery of culturable E. coli towards slightly higher values. When an antifoaming agent was added to the peptone solution there was little overall change in the amount of E. coli recovered. Betaine was also determined to be an effective osmoprotectant, with 101, 77, and 41% of E. coli recovered from the impingers at 30, 60, and 90 min, respectively. The results from this study support the incorporation of osmoprotectants in collection fluids, but not use of DI water and PBS, when BioSampler runtimes up to 90 min will be utilized. Runtimes longer than 30 min are sometimes necessary when the airborne concentration of a target organism is low and one is trying to increase the probability of detection
Soil health, crop productivity, microbial transport, and mine spoil response to biochars
Get PDFBiochar is being evaluated by scientists from the United States Department of Agriculture (USDA) Agricultural Research Service (ARS) for its potential to sequester soil C, to improve soil health, and to increase crop yields. ARS scientists from multiple locations such as Florence, SC, Kimberly, ID, Bowling Green, KY, Corvallis, OR, and St. Paul, MN, are conducting investigations with agronomic experiments at the laboratory, greenhouse, and field plot scales. To further expand biochars utility, ARS scientists have collaborated with United States Environmental Protection Agency (US EPA) investigators to reclaim mine-impacted soils. In the agronomic investigations, both positive and negative aspects of biochar application were revealed. In some experiments, biochars were reported to have no effect on crop yields, and minimal impact on movement of microbial pathogens through soil. In other experiments, biochars were reported to improve soil fertility, increase water retention, and bind with heavy metals in solutions and in mine spoil soils. This variation in biochars influence, substantiates and encourages further work on the designer biochar concept, which states that the biochars can be crafted for targeted agronomic and environmental purposes. There is a need to broadcast the successes and failures of biochar research reported by scientists from both agencies. Consequently, the objectives of this review are: to report on biochar effectiveness as a soil amendment; to ascertain its ability to modify soil properties, to evaluate its impact on soil leaching of microbes; and its potential capacity to help reclaim mine spoil sites
Impacts of dietary forage and crude protein levels on the shedding of Escherichia coli O157:H7 and Listeria in dairy cattle feces
Get PDFShedding of Escherichia coli O157:H7 and Listeria monocytogenes in ruminant manure is well reported. However, the influence of dietary manipulation on the shedding of the pathogens is not well understood. This study was conducted to improve the understanding of the relationship between dietary feed composition and pathogen shedding in dairy feces, particularly E. coli O157:H7 and L. monocytogenes. Twelve cows were randomly assigned to a 2 × 2 factorial arrangement of 2 dietary forage levels: low forage (37.4% of dry matter [DM]) vs. high forage (HF, 53.3% of DM) and two dietary crude protein (CP) levels: low protein (LP, 15.2% of DM) vs. high protein (HP, 18.5% of DM) in a 4 × 4 replicated Latin square design with four periods each including 15 d adaptation and 3 d sample collection. In CP treatments, significantly low concentrations of L. monocytogenes were observed from cows fed the HP (0.9-1.6 log10 cfu/g) compared to the LP diet (1.3–2.1 log10 cfu/g). Significant interaction effect was observed between dietary forage and crude protein on the presence of E. coli O157:H7 (P < 0.05) but not on L. monocytogenes. On average, the highest E. coli O157:H7 concentration (6.5 log10 cfu/g of feces) was observed from the HF and HP diet and the lowest concentration was 6.2 log10cfu/g from the HF and LP diet. The average L. monocytogenes shedding was within the range of 1.8 to 2.4 log 10cfu/g among the treatments. The study showed that diet has an influence on the shedding of pathogenic bacteria in dairy excreta
Resistance to Beet curly top in USDA-ARS Ft. Collins germplasm, 2015
Get PDFFifty sugar beet (Beta vulgaris L.) germplasm lines produced by the USDA-ARS Ft. Collins sugar beet program and two commercial check cultivars [SV2012RR (susceptible) and HM PM90 (resistant)] were screened for resistance to Beet curly top virus (BCTV). The curly top evaluation was conducted at the USDA-ARS North Farm in Kimberly, ID, which had been in barley in 2014. The germplasm was planted (density of 142,560 seeds/A) on May 27. The plots were two rows 10 ft long with 22-in row spacing and arranged in a randomized complete block design with three replications. The fields were sprinkler irrigated, cultivated, and hand weeded as necessary. Plant populations were thinned on June 20 Plants were inoculated at the four- to six-leaf growth stage on June 24 Jun with approximately six viruliferous beet leafhoppers per plant. The beet leafhoppers were redistributed by dragging a tarp through the field. The plants were sprayed with Lorsban 4E (1.5 pints/A) on July 7 to kill the beet leafhoppers. Plots were rated for foliar symptom development on 13 and 20 Jul using a disease index scale (DI) of 0 to 9 (0 = healthy and 9 = dead). Data were analyzed in SAS using the general linear models procedure (Proc GLM), and Fisher’s protected least significant difference (LSD; a = 0.05) was used for mean comparisons. We are reporting the second and most severe disease rating scores. There were significant differences among entries. Additionally, an analysis of variance (PROC MIXED) was performed on DI, and Dunnett’s one-tailed t-test (p = 0.05), adjusted for sample size, was used to compare all entries to the resistant control (HM PM90) and the most susceptible germplasm (20121034) for DI. Curly top symptom development was uniform and no other disease problems were evident in the plot area. The resistant and susceptible checks performed as expected for both visual ratings. The DI was 4.0 in the resistant control and 7.9 in the most susceptible entry. Those entries, for which DI 6.2, were not significantly different than the most susceptible entry (20121034) (Dunnett’s one tailed t-test, p = 0.05). Those entries for which DI > 5.4 and DI < 6.4 showed a moderate resistance, significantly more resistant than the most susceptible entry but significantly more susceptible than the resistant control. Based on their performance, entries will be released for resistance to BCTV or re-selected to improve their resistance to BCTV. All germplasms developed by the USDA-ARS pre-breeding program at Fort Collins are screened for BCTV before release; even if they have not been selected primarily for BCTV-resistance, because this is useful information for other plant breeders wishing to incorporate released germplasm into their breeding programs