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Evaluations of Ft. Collins sugar beet germplasm for rhizomania and storage rot resistance in Idaho, 2016
Get PDFFifty sugar beet (Beta vulgaris L.) lines from the USDA-ARS Fort Collins sugar beet program and four check cultivars were screened for resistance to Beet necrotic yellow vein virus (BNYVV), the causal agent of rhizomania, and to fungal growth in storage, which is related to storage rot. The rhizomania (RZ) evaluation was conducted at the USDA-ARS North Farm in Kimberly, ID, which had been in barley in 2015. The field was fall plowed, fertilized and roller harrowed before plant to a density of 142,560 seed/A. The plots were single row 10-ft long with 22-in. row spacing and arranged in a randomized complete block design with 6 replications. The crop was managed according to standard cultural practices for southern Idaho and plants were thinned to 47,500 plants/A . The trial relied on endemic field inoculum for rhizomania and storage rot development. The plots were rated for foliar symptom (percentage of plants with yellow, stunted, upright leaves) development on August 18th, were mechanically topped and hand harvested on October 13th. At harvest, ten roots per plot were rated for rhizomania symptom development using a scale of 0 to 9 (0 = healthy and 9 = dead), with disease index (DI) treated as a continuous variable. At harvest, eight of the evaluated roots per plot also were placed in a mesh-onion bag and put on top of the pile in an indoor commercial storage facility (temperature set point 34°F) in Paul, ID. On February 9, 2017, after 118 days in storage, the roots were evaluated for the percentage of root surface area covered by any fungal growth. Data were analyzed in SAS using the general linear models procedure (Proc GLM), and Fisher’s protected least significant difference (a = 0.05) was used for mean comparisons. The foliar data were square root transformed prior to analysis. Rhizomania symptom development was uniform and no other disease symptoms were evident in the plot area. The BNYVV susceptible check plots (Check 1) had 81% foliar symptoms and a high root disease severity rating of 46. The three resistant checks (2, 3, and 4) had 0 to 7% foliar symptoms and low root disease severity ratings (18 to 24). Based on root ratings, all but three entries had some resistance, because these were the only entries not different from the susceptible check. Four entries (20141007, 20141009, 20131010H11, and 20131010H10) had good rhizomania resistance based on both root symptoms and foliar ratings because these did not significantly differ from more of the resistant checks. A number of entries performed well in storage, four entries only had single digit fungal growth and 20 others were not significantly different from these four, although these were not always the same entries that showed resistance to BNYVV. Some of these entries may serve as a starting point for identifying additional sources of resistance to BNYVV and storage rots
Beet curly top resistance in USDA-ARS plant introduction lines, 2016
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, twenty-nine Plant Introduction (PI) Lines were screened in a disease nursery in 2016. The lines were arranged in a randomized complete block design with four replications. A curly top epiphytotic was created by releasing approximately six viruliferous beet leafhoppers per plant at the four- to six-leaf growth stage on 20 Jun. Foliar symptoms were evaluated on 13 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. Three of the PIs were not significantly different from the resistant checks based on the visual rating. These promising lines have been incorporated into the USDA-ARS sugar beet germplasm improvement program as potentially novel sources of resistance to BCTV
Effects of diet and manure storage method on carbon and nitrogen dynamics during storage and plant nitrogen uptake
Get PDFAltering dairy cattle diets to reduce both enteric methane (CH4) production and nitrogen (N) excretion are valuable tools for mitigating the environmental impact of dairy production. We examined the impact of altering diets on changes in physicochemical properties of manure during storage, short term plant N availability, and overall system N use efficiency. Manure collected from cattle fed diets with differing forage and crude protein (CP) content were stored via three methods (slurry, static pile, turned pile) for 29 weeks and sampled at week 0, 1, 2, 3, 4, 9, 14, 19, 24, and 29. Mass losses of total carbon (C) ranged from 28 to 50% and followed the trend static pile > slurry > turned pile (P < 0.01). Total N losses ranged from 20 to 47% with the slurry and static pile treatments having larger (but similar) losses than the turned pile treatment (P < 0.01). The soil 2-week plant available N was similar in the static pile and turned pile treatments and were 67% less than the slurry treatment. The short-term plant N use efficiency was similar for both the static pile and slurry treatments (22-24%), which were greater than that of the turned pile treatment (16%). Overall estimated system N use efficiencies were 5% greater for lower CP diets compared to high CP diets. While rapidly drying manure may conserve C and N, there may be a tradeoff with plant N utilization which could affect overall system efficiencies
Irrigated sugarbeet sucrose content in relation to growing season climatic conditions in the northwest U.S.
Get PDFThe potential effects of changing climate on world food production have become a political and scientific focus. This study was conducted to investigate linkages between seasonal climatic conditions and sugarbeet sucrose content in southern Idaho and eastern Oregon. Sucrose content of irrigated sugarbeets delivered to 74 receiving stations in southern Idaho and eastern Oregon from 1997 through 2014, and daily climate data (growing degree days [GDD] and accumulated alfalfa reference crop evapotranspiration, maximum air temperature, minimum air temperature and mean air temperature, global solar radiation, accumulated growing degree days, and mean relative humidity) from regional weather stations were collected and analyzed using various regression techniques to investigate linkages between climate variables and sugarbeet sucrose content. Ninety-nine climatic parameters were analyzed with 34 having correlations with sugarbeet sucrose content > |0.3|. The most important climatic parameter related to mean sucrose content was early stage sugarbeet growth (late April to mid-May). In general, as temperature and GDD increased sucrose content decreased. Results indicate increases in both early season and mid-season temperatures will lead to decreases in sugarbeet sucrose concentrations. However, if sugarbeet root yields increase due to increasing temperatures and GDD accumulation, the sucrose yield changes would be buffered
A novel penicillium sp. causes rot in stored sugar beet roots in Idaho
Get PDFPenicillium vulpinum along with a number of other fungi can lead to the rot of stored sugar beet roots. However, Penicillium isolates associated with necrotic lesions on roots from a recent sugar beet storage study were determined to be different from P. vulpinum and other recognized Penicillium species. Phylogenies based on sequencing of the internal transcribed spacer (ITS)-5.8S, beta-tubulin (BenA), and RNA polymerase II second largest subunit (RPB2) DNA regions indicate that these isolates are novel, but most closely related to the following Penicillium spp. in the section Fasiculata: P. aurantiogriseum, P. camemberti, and P. freii. Macro- and micromorphological data also support designating these isolates as a new species for which we propose the name, Penicillium cellarum sp. nov. Inoculation studies with the P. cellarum isolates on roots of the commercial sugar beet cultivar B-7, led to the formation of necrotic lesions 23 to 25 mm in diameter after 86 days in storage. These lesions were similar to those observed on sugar beet roots in commercial storage piles. These data indicate that P. cellarum is a pathogen which can lead to root rot in stored sugar beet roots
Occurrence of antibiotics in an agricultural watershed in south-central Idaho
Get PDFThe polar organic compound integrative sampler (POCIS) is a tool that has been effectively used to passively sample organic pollutants in water. In this study, POCIS were used to investigate the occurrence of 21 veterinary and human antibiotics and a beta agonist (ractopamine) in irrigation return flows of an intensively managed agricultural watershed in south-central Idaho. Erythromycin-H2O, monensin, oxytetracycline, ractopamine, sulfadimethoxine, sulfamethazine, sulfamethoxazole, trimethoprim, and tylosin were detected at frequencies ranging from 3.1 to 62.5%, with monensin having the highest rate of detection. Based on uptake rates from published literature, aqueous concentrations were estimated to range from 0.003 ng L-1 for tylosin to 249 ng L-1 for oxytetracycline. While monensin had the lowest time-weighted average concentration (0.24 ng L-1), the fact that it was the most frequently detected compound suggests that a portion of the pharmaceuticals were entering the return flows as runoff from animal manure-treated fields during the irrigation season. The same pharmaceuticals (except oxytetracycline, sulfamethazine, and tylosin) were also detected at a background site that consisted of diverted Snake River water that is the source of irrigation water for the watershed. Therefore, antibiotics, as well as ractopamine, are likely being applied to soils and transported with runoff to irrigation return flows. This study provides additional evidence that surface waters within agricultural watersheds contain low-level pharmaceuticals associated with veterinary and human uses
Effect of rainfall timing and tillage on the transport of steroid hormones in runoff from manure amended row crop fields
Get PDFManure generated from concentrated animal feeding operations (CAFOs) represents one of the major sources of steroid hormones found in surface water. This paper presents results of a study conducted near Concord, NE to determine the effects of manure handling (compost vs. stockpile), tillage (no-till, plow plus disk and disk), and rainfall timing (24 h and 30 d after manure application (DAT)) on the transport of steroids from row crop fields via surface runoff. Manure was collected following a feedlot study where one set of female cattle were administered growth promoting steroids and mycotoxins and one set received no treatments. Manure was either stockpiled for 9 months or composted prior to application. Twelve of 17 steroids or their metabolites were identified in the manure that was applied at agronomic rates to cropland in a no-till production system for more than 5 years. Chemical analysis of runoff samples detected steroids in less than 50% of the runoff samples and less than 10% of the samples contained more than one individual steroid or mycotoxin. The median concentration of androgens, and progestagens in surface runoff samples decreased by more than 50% between the 1 DAT to 30 DAT sampling dates. The percentage of detections increased between 24-h and 30-d after manure application largely due to increased levels of mycotoxins produced by the Fusarium genus of fungi common to corn fields. In addition, the physical and chemical properties of the steroids result appear to contribute to their long term degradation once applied to the soil. Based on this study, the combination of stockpiling manure prior to application and incorporation into the soil would likely result in the least potential for steroid transport to surface waters
Pathogenicity, vegetative compatibility, and genetic diversity of verticillium dahliae isolates from sugar beet
Get PDFVerticillium wilt of sugar beet is a disease problem that has received very little attention in the literature, but has been reported to reduce sucrose production and purity. To improve our understanding of the disease, a survey of sugar beet plants with wilt symptoms in Idaho was conducted in 2007 (5 roots from each of 40 fields; 200 roots total) and 2008 (5 roots from each of 45 fields; 225 roots total). Verticillium dahliae was isolated from all plants, while Fusarium oxysporum was isolated from 19 and 21% of the plants in 2007 and 2008, respectively. From a collection of 106 V. dahliae sugar beet isolates, all isolates had the MAT1-2 mating type and 95% evaluated for vegetative compatibility group (VCG) were 4A, while 1, 1, and 3% were non-compatible, VCG 4B, and VCG 2B, respectively. All the 4A isolates had the same mitochondrial haplotype based on sequencing of the cox3 to nad6 and cox1 to rnl loci. In greenhouse pathogenicity tests on sugar beet cultivar ‘Monohikari', the VCG 4A isolates produced more foliar symptoms (P < 0.0001) than VCG 1, 1A, 2A, 2B, 3, and 4B isolates, but none of the VCGs consistently reduced root and top weight. Since V. dahliae VCG 4A strains have also been documented to be the primary cause of Verticillium wilt in potato in North America, rotating sugar beet with potato could be a concern, but unlike potatoes, sugar beet plants do not seem to die from infection
Improving nitrogen management in pacific northwest sugarbeet production
Get PDFNitrogen management is critical in sugarbeet production to optimize yield and quality. Although, past research has been critical to improving sugarbeet nitrogen nutrition, continued research is needed to evaluate evolving varieties and management practices. From 2005 to 2010, studies from 14 locations were conducted by agronomists from The Amalgamated Sugar Company and scientists at the USDA-ARS Northwest Irrigation and Soils Research Laboratory to evaluate the effect of N supply (fertilizer N + N in soil) on sugarbeet production in the Pacific Northwest. At each location, the effect of various levels of N supply on estimated recoverable sucrose yield, root yield, sucrose concentration, brei nitrate concentration, and nitrogen use efficiency were assessed. Nitrogen supply significantly affected estimated recoverable sucrose yield for 6 of the 14 locations. For the 8 non responsive sites, the maximum estimated recoverable sucrose yield was assumed to be the lowest N supply. The average nitrogen requirement at maximum estimated recoverable sucrose yield across all site-years was 2.25 kilogram nitrogen per megagram of beet yield and ranged from 1.4 to 3.7. Thirteen of the 14 locations had a nitrogen requirement at or below 2.8 kilogram nitrogen per megagram of beet yield, substantially less than current recommendations of 3.5 to 4.0. Nitrogen requirements can be reduced in the Pacific Northwest sugarbeet production area compared to past recommendations resulting in reduced N fertilizer applications and significant cost savings
Moving spray-plate center-pivot sprinkler rating index for assessing runoff potential
Get PDFNumerous moving spray-plate center-pivot sprinklers are commercially available providing a range of drop size distributions and wetted diameters. A means to quantitatively compare sprinkler choices in regards to maximizing infiltration and minimizing runoff is currently lacking. The objective of this study was to develop a soil independent quantitative runoff potential index to facilitate selection of sprinklers for center-pivot sprinkler irrigation systems. Drop sizes, velocities and water application rates of numerous moving spray-plate sprinklers were measured in the laboratory over a range of flow rates and operating pressures. The proposed sprinkler runoff index is based on application rates of kinetic energy and water computed by overlapping specific power and water application profiles of sprinklers equally spaced 3 m along a center-pivot lateral. Results show that substantial differences in runoff potential exist between sprinkler choices and several sprinklers can have similar runoff potential index values. In some cases, equivalent potential runoff index values were obtained with compensating differences in specific power and application rate. The proposed sprinkler runoff index provides a new and unique approach for evaluating moving spray-plate sprinklers in regards to runoff potential and provides an effective means for comparing sprinkler choices by identifying sprinklers with large drops and relatively small wetted diameters