Regional analysis of planting date and cultivar maturity recommendations that improve soybean oil yield and meal protein concentration.

Planting date and cultivar maturity group (MG) are major management factors affecting soybean [Glycine max (L.) Merr.] yield, but their effect on seed oil and protein concentration, and in particular meal protein concentration, is less understood. We quantified changes in seed oil and protein, and estimated meal protein concentration, and total oil and protein yield in response to planting date and cultivar MG ranging from 3 to 6 and across locations comprising a 8.3° range in latitude in the U.S. Midsouth. Our results show that delayed planting date and later cultivar maturity reduced oil concentration, and this was partially associated with a decrease in temperature during the seed fill phase. Thus, optimum cultivar MG recommendations to maximize total oil yield (in kg ha-1) for planting dates in May and June required relatively earlier cultivar MGs than those recommended to maximize seed yield. For planting dates in April, short-season MG 3 cultivars did not increase oil yield compared to full-season MG 4 or 5 cultivars due to a quadratic yield response to planting date at most locations. Planting date and cultivar maturity effects on seed protein concentration were not always consistent with the effects on estimated meal protein concentration after oil extraction. Meal protein concentration decreased with lower temperatures during seed fill, and when the start of seed fill occurred after August 15, but relatively short-season cultivar MGs reduced the risk of low meal protein concentration. Meal protein concentration is a trait of interest for the feed industry that would be beneficial to report in future studies evaluating genetic, management, and environmental effects on seed protein concentration.

The Short-Term Effect of Whey Compared with Pea Protein on Appetite, Food Intake, and Energy Expenditure in Young and Older Men.

BACKGROUND: Diets higher in protein have been reported to improve age-related changes in body composition via increased energy expenditure, shifts in substrate oxidation (SO), and decreased appetite. However, how protein source (e.g., animal compared with plant protein) affects energy expenditure, appetite, and food intake as we age is unknown. OBJECTIVES: The objective of this study was to evaluate the effect of protein source as part of a high-protein breakfast on appetite, food intake, energy expenditure, and fat oxidation in young men (YM) compared with older men (OM). METHODS: This study used a randomized, single-blinded crossover design, with a 1-wk washout period between testing days. Fifteen YM (mean ± SD age: 25.2 ± 2.8 y) and 15 OM (67.7 ± 4.5 y), healthy adults, participated in the study. Participants arrived fasted and consumed an isocaloric, volume-matched, high-protein (40-g) test beverage made with either an animal [whey protein isolate (WPI)] or plant [pea protein isolate (PPI)] protein isolate source. Markers of appetite and energy expenditure were determined at baseline and over 4 h postprandial. RESULTS: There was a significant effect of time, age, and protein source on appetite (P < 0.05). There was no effect of protein source on plasma markers of appetite, food intake, energy expenditure, and SO. After controlling for body weight, OM had decreased energy expenditure (P < 0.05) and lower fat oxidation (P < 0.001) compared with YM. CONCLUSIONS: This study indicates that a high-protein breakfast containing WPI or PPI exerts comparable effects on appetite, energy expenditure, and 24-h energy intake in both young and older healthy adult men.This trial was registered at clinicaltrials.gov as NCT03399812.

Effectiveness of a Seed Plate Assay for Evaluating Charcoal Rot Resistance in Soybean and the Relationship to Field Performance.

Charcoal rot of soybean, caused by Macrophomina phaseolina, is a disease of economic significance in the United States. Although there are soybean cultivars with moderate resistance, identifying and quantifying resistance is challenging. Existing assays are time consuming, and results are often highly variable. The objectives of this research were to (i) create a reproducible seed plate assay (SPA) for charcoal rot resistance and (ii) correlate field-based disease assessments with SPA results on diverse soybean accessions. To develop the SPA, surface-disinfected seeds from eight soybean genotypes (representing three susceptible and five resistant cultivars) were placed on water agar plates inoculated with M. phaseolina. After incubation at room temperature in darkness for 7 days, percent germination was determined for each cultivar relative to the germination on noninoculated plates. Results from SPA were in general agreement with published responses. None of the soybean genotypes showed complete resistance to M. phaseolina. For the second objective, charcoal rot resistance in 18 soybean accessions was assayed with SPA, and results were analyzed for correlation with field disease assessments from Stuttgart, AR, from 2011 to 2014 and from Rohwer, AR, in 2011 and 2012. SPA consistently categorized soybean genotype resistance compared with field disease assessment averages, and results were consistent with previously published resistance determinations. SPA was significantly correlated with percent height of internal stem discoloration (PHSD) at Stuttgart from 2011 to 2013 and in 2012 at Rohwer, with root and stem severity (RSS) at Rohwer in 2012, and with tap root colonization (CFU) at Stuttgart in 2012. SPA was significantly correlated to yield at Stuttgart in 2011, 2013, and 2014, and in 2011 and 2012 at Rohwer. Yield was not correlated to RSS, PHSD, or CFU at either location or in any year. Therefore, SPA is a reproducible and rapid assay for charcoal rot resistance in soybean and is significantly associated to field performance.

Transmissible Plasmids and Integrons Shift Escherichia coli Population Toward Larger Multiple Drug Resistance Numbers.

Transmissible plasmids and integrons may play important roles in the persistence and spread of antibiotic-resistant bacteria throughout aquatic environment by accumulating antibiotic resistance genes (ARG). Class 1 and class 2 integron (intI), mobilization (mob), sulfamethoxazole resistance (sul), and trimethoprim resistance (dfr) genes were PCR-amplified and confirmed through DNA sequencing following plasmid extraction from 139 antibiotic-resistant Escherichia coli. E. coli had previously been recovered from wastewater treatment plant effluent and receiving stream water in Northwest Arkansas and isolates had expressed resistance to one to six antibiotics. Almost half of the total isolates (47%) carried putatively transmissible plasmids with mobF12 gene as the most frequently detected mobilization gene. When two or three mob genes were detected per isolate, there was a significant shift in the population toward larger multiple drug resistance (MDR) number. Class 1 and/or 2 integrons were prevalent (46%), and the presence of integron significantly shifted the isolate population toward larger MDR number. More isolates carried single or coexistence of two or three sul genes (99.3%), and single or a combination up to five dfr genes (89.3%) than had exhibited in vitro resistance to the respective antibiotics. These findings indicate not only the role of the wastewater treatment effluent and the stream environment in coaccumulation of ARG with transmissible plasmids and integrons in multiple antibiotic-resistant E. coli populations but also suggest that density of sul and dfr resistance genes within an isolate may serve as a biomarker for mobile MDR in general.

Impact of volunteer rice infestation on yield and grain quality of rice.

BACKGROUND: Volunteer rice (Oryza sativa L.) grains may differ in physicochemical traits from cultivated rice, which may reduce the quality of harvested rice grain. To evaluate the effect of volunteer rice on cultivated rice, fields were surveyed in Arkansas in 2012. RESULTS: Cropping history that included hybrid cultivars in the previous two years (2010 and 2011) had higher volunteer rice infestation (20%) compared with fields planted previously with inbred rice (5.5%). The total grain yield of rice was reduced by 0.4% for every 1% increase in volunteer rice density. The grain quality did not change in fields planted with the same cultivar for three years. Volunteer rice density of at least 7.6% negatively impacted the head rice and when infestation reached 17.7%, it also reduced the rice grain yield. The protein and amylose contents of rice were not affected until volunteer rice infestation exceeded 30%. CONCLUSION: Crop rotation systems that include hybrid rice are expected to have higher volunteer rice infestation than systems without hybrid rice. It is predicted that, at 8% infestation, volunteer rice will start to impact head rice yield and will reduce total yield at 18% infestation. It could alter the chemical quality of rice grain at >30% infestation. © 2016 Society of Chemical Industry.

Short communication: On recognizing the proper experimental unit in animal studies in the dairy sciences.

Sound design of experiments combined with proper implementation of appropriate statistical methods for data analysis are critical for producing meaningful scientific results that are both replicable and reproducible. This communication addresses specific aspects of design and analysis of experiments relevant to the dairy sciences and, in so doing, responds to recent concerns raised in a letter to the editor of the Journal of Dairy Science regarding journal policy for research publications on pen-based animal studies. We further elaborate on points raised, rectify interpretation of important concepts, and show how aspects of statistical inference and elicitation of research conclusions are affected.

Genetic redundancy and persistence of plasmid-mediated trimethoprim/sulfamethoxazole resistant effluent and stream water Escherichia coli.

Antibiotic resistant bacteria may persist in effluent receiving surface water in the presence of low (sub-inhibitory) antibiotic concentrations if the bacteria possess multiple genes encoding resistance to the same antibiotic. This redundancy of antibiotic resistance genes may occur in plasmids harboring conjugation and mobilization (mob) and integrase (intI) genes. Plasmids extracted from 76 sulfamethoxazole-trimethoprim resistant Escherichia coli originally isolated from effluent and an effluent-receiving stream were used as DNA template to identify sulfamethoxazole (sul) and trimethoprim (dfr) resistances genes plus detect the presence of intI and mob genes using PCR. Sulfamethoxazole and trimethoprim resistance was plasmid-mediated with three sul (sul1, sul2 and sul3 genes) and four dfr genes (dfrA12, dfrA8, dfrA17, and dfrA1 gene) the most prevalently detected. Approximately half of the plasmids carried class 1 and/or 2 integron and, although unrelated, half were also transmissible. Sampling site in relationship to effluent input significantly affected the number of intI and mob but not the number of sul and dfr genes. In the presence of low (sub-inhibitory) sulfamethoxazole concentration, isolates persisted regardless of integron and mobilization gene designation, whereas in the presence of trimethoprim, the presence of both integron and mobilization genes made isolates less persistent than in the absence of both or the presence of a gene from either group individually. Regardless, isolates persisted in large concentrations throughout the experiment. Treated effluent containing antibiotic resistant bacteria may be an important source of integrase and mobilization genes into the stream environment. Sulfamethoxazole-trimethoprim resistant bacteria may have a high degree of genetic redundancy and diversity carrying resistance to each antibiotic, although the role of integrase and mobilization genes towards persistence is unclear.

Fermentation of Soybean Meal Hydrolyzates with Saccharomyces cerevisiae and Zymomonas mobilis for Ethanol Production.

Most of the ethanol currently produced by fermentation is derived from sugar cane, corn, or beets. However, it makes good ecological and economic sense to use the carbohydrates contained in by-products and coproducts of the food processing industry for ethanol production. Soybean meal, a co-product of the production of soybean oil, has a relatively high carbohydrate content that could be a reasonable substrate for ethanol production after fermentable sugars are released via hydrolysis. In this research, the capability of Saccharomyces cerevisiae NRRL Y-2233 and Zymomonas mobilis subsp. mobilis NRRL B-4286 to produce ethanol was evaluated using soybean meal hydrolyzates as substrates for the fermentation. These substrates were produced from the dilute-acid hydrolysis of soybean meal at 135 °C for 45 min with 0, 0.5%, 1.25%, and 2% H2 SO4 and at 120 °C for 30 min with 1.25% H2 SO4 . Kinetic parameters of the fermentation were estimated using the logistic model. Ethanol production using S. cerevisiae was highest with the substrates obtained at 135 °C, 45 min, and 0.5% H2 SO4 and fermented for 8 h, 8 g/L (4 g ethanol/100 g fresh SBM), while Z. mobilis reached its maximum ethanol production, 9.2 g/L (4.6 g ethanol/100 g fresh SBM) in the first 20 h of fermentation with the same hydrolyzate.

Soil respiration as affected by long-term broiler litter application to a udult in the ozark highlands.

The United States produced 8.4 billion broiler chickens () and an estimated 10.1 to 14.3 million Mg of broiler litter (BL) in 2012. Arkansas' production of 1 billion broilers in 2012 produced an estimated 1.2 to 1.7 million Mg of BL, most of which was concentrated in the Ozark Highlands region of northwest Arkansas. Increased CO release from soils associated with agricultural practices has generated concerns regarding the contribution of certain agricultural management practices to global warming. The objectives of this study were to evaluate the effects of long-term (>6 yr) BL application to a Udult on soil respiration and annual C emissions and to determine the predictability of soil respiration based on soil temperature and moisture in the Ozark Highlands region of northwest Arkansas. Soil respiration was measured routinely between May 2009 and May 2012 in response to annual BL application rates of 0, 5.6, and 11.2 Mg dry litter ha that began in 2003. Soil respiration varied ( < 0.01) with BL rate, measurement date, and year. Additions of BL stimulated respiration after application, and rainfall events after dry-soil conditions stimulated respiration in all years. Soil temperature at the 10-cm depth, 0- to 6-cm soil volumetric water content (VWC), and annual CO-C emissions were unaffected ( > 0.05) by BL application rate but differed ( < 0.01) among study years. Multiple regression indicated that soil respiration could be reasonably predicted using 2-cm-depth soil temperature (T) and the product of T and VWC as predictors ( = 0.52; < 0.01). Results indicate that organic amendments, such as BL, can stimulate release of CO from the soil to the atmosphere, potentially negatively affecting atmospheric greenhouse gas concentrations; thus, there may be application rates above which the benefits of organic amendments may be diminished by adverse environmental effects. Improved BL management strategies are needed to lessen the loss of CO from BL-amended soils.

Nematodes as bioindicators of ecosystem recovery during phytoremediation of crude oil contaminated soil.

Restoration of a weathered crude oil contaminated site undergoing phytoremediation was evaluated using nematodes as bioindicators. Samples were collected twice per year equating to spring and fall/winter. Mean annual total abundances ranged from 18-130 in the non-fertilized non-vegetated control (CTR) to 69-728 in tall fescue-ryegrass (FES) to 147-749 (100 g(-1)) in the fertilized bermudagrass-fescue (BER) treatment. Proportions of plant-parasitic (PP) and free-living (FL) nematodes were significantly impacted by treatment, but not year, with PP nematodes accounting for 27, 59, and 68% of CTR, FES, and BER communities, respectively. There was no significant year by season by treatment or treatment by year effect for total, PP, or FL nematode abundances. Diversity did not increase over time. The BER and FES treatments had more mature communities as indicated by higher plant-parasitic index (PPI) values. Phytoremediation accelerates petroleum degradation and alters the soil habitat which is reflected in the nematode community. However, low numbers and inconsistent presence of persister strategist omnivores and predators, and the lack in improvement over time in treatment effects for total and PP nematode abundances, PP and FL proportions, or PPI indicate the system is being rehabilitated but has not been restored after 69 months of phytoremediation.

Methane emissions from drill-seeded, delayed-flood rice production on a silt-loam soil in arkansas.

Rice ( L.) production is unique among staple food crops because the majority of the growing season typically occurs under flooded-soil conditions. Flooding the soil leads to anaerobic conditions, which are a precursor to methane (CH) production. However, no known research has investigated CH emissions from the drill-seeded, delayed-flood rice production system common in Arkansas, the leading rice-producing state in the United States. Therefore, research was conducted in 2011 to determine the effects of vegetation (rice and bare soil), chamber location (in- and between-rice rows), and nitrogen (N) fertilization (optimal and no N) on CH emissions from a silt-loam soil. Methane fluxes measured weekly from flooding until flood release were affected by vegetation, chamber location, and sample date ( < 0.05). In-row CH fluxes were <0.7 mg CH-C m h until 20 d after flooding (DAF) and <1.0 mg CH-C m h from between-row and bare soil until 41 DAF and were unaffected by fertilization over time. The largest weekly measured CH flux (31.9 mg CH-C m h) was observed from in-row rice at 41 DAF. Post-flood-release CH fluxes were affected by vegetation, fertilization, chamber placement, and sample date ( < 0.05) and accounted for approximately 3 to 7% of the season-long CH emissions. Methane emissions averaged 195 kg CH-C ha per growing season and were unaffected by fertilization. Direct measurement of CH emissions from drill-seeded, delayed-flood rice grown on a silt-loam soil will improve the accuracy of assessments of the carbon footprint and long-term sustainability of rice.

Characterization of Resistance to Stripe Rust in Contemporary Cultivars and Lines of Winter Wheat from the Eastern United States.

Stripe rust, caused by Puccinia striiformis f. sp. tritici, has been an important disease of winter wheat (Triticum aestivum) in the eastern United States since 2000, when a new strain of the pathogen emerged. The new strain overcame the widely used resistance gene, Yr9, and was more aggressive and better adapted to warmer temperatures than the old strain. Host resistance is the most effective approach to manage stripe rust. Winter wheat lines with resistance to the new strain in the field are common, but the genes conferring this resistance are mostly unknown. The objectives of this research were to characterize the all-stage resistance and adult-plant resistance (APR) to stripe rust in a representative group of contemporary winter wheat cultivars and breeding lines and to identify the resistance genes when possible. Of the 50 lines evaluated for all-stage resistance at the seedling stage, nearly all were susceptible to the new strain. Based on a linked molecular marker, seven lines had resistance gene Yr17 that confers resistance to both old and new strains; however, this resistance was difficult to identify in the seedling stage. Of the 19 lines evaluated for APR, all expressed APR compared with a very susceptible check. Nine had race-specific APR to the new strain and nine had APR to both old and new strains. The remaining line, 26R61, had all-stage resistance to the old strain (conferred by resistance gene Yr9) and a high level of APR to the new strain. APR was expressed as low infection type, low percent leaf area diseased, and long latent period at heading stage under both low and high temperature regimes and could be identified as early as jointing stage. Based on tests for linked molecular markers, the most widely used slow-rusting APR genes, Yr18 and Yr29, were not present in any of the lines. The results of this research indicate that effective all-stage resistance was conferred only by Yr17 and that APR was common and likely conferred by unknown race-specific genes rather than genes conferring slow rusting that are more likely to be durable.

Extraction, fractionation and characterization of bitter melon seed proteins.

Protein fractions (water-soluble/albumin, salt-soluble/globulin, alkali-soluble/glutelin, and alcohol-soluble/prolamin) were extracted from defatted ripe bitter melon seed (Momordica charantia) using water, 1 M sodium chloride solution, alkali/pH 11.0, and 70% ethanol, sequentially. The main protein fraction was albumin (49.3%), followed by globulin (29.3%) and glutelin (3.1%). No prolamin was detected, and 18.3% of the protein was nonextractable. The surface hydrophobicities of albumin, globulin, and glutelin were 757, 1,034, and 292, respectively. The molecular sizes of all the fractions were mostly about 45 and 55 kDa. The denaturation temperatures of albumin, globulin, and glutelin were 111.9, 117.3, and 133.6 degrees C, respectively. The levels of all essential amino acids in the bitter melon protein fractions met the minimum requirements for preschool children (FAO/WHO/UNU) with the exception of Thr. Bitter melon protein fractions with unique protein profiles and higher denaturation temperatures could impart novel characteristics when used as food ingredients.

Pesticide extraction efficiency of two solid phase disk types after shipping.

An interlaboratory study was conducted to compare pesticide recovery from Empore C(18) and Speedisks C(18)XF solid phase extraction disks after shipping. Four pesticides were used for the comparison of the two disk extraction materials: atrazine, diazinon, metolachlor, and tebuconazole. These pesticides were chosen to provide a range of physiochemical properties. Water samples were extracted onto the disk types and shipped to a cooperating laboratory for elution and analysis. The mean recoveries from Empore disks were atrazine, 95%; diazinon, 91%; metolachlor, 92%; and tebuconazole, 83%. The recoveries from Speedisks C(18)XF were atrazine, 89%; diazinon, 87%; metolachlor, 86%; and tebuconazole, 79%. Means for each of the pesticides using the different disk types were not statistically different (alpha = 0.05), but results were more variable when using Speedisks C(18)XF as compared to Empore disks. Reasons for the increased variability are discussed, but overall results indicate that Speedisks C(18)XF could be used as an alternative to Empore disks. Speedisks C(18)XF are enclosed in a plastic housing, so they can be used more easily in remote sampling sites without the possibility of glassware breakage, no prefiltration of samples is needed, and there are realignment problems that can be associated with the Empore disks.