Crop Science Research Laboratory

This paper provides the first nationally representative estimates for use of four emerging products. Addressing the issue of land-line substitution with cell phones, we used a mixed-mode survey to obtain two representative samples of US adults. Of 3,240 eligible respondents contacted, 74% completed surveys. In the weighted analysis, 13.6% have tried at least one emerging tobacco product; 5.1% snus; 8.8% waterpipe; 0.6% dissolvable tobacco products; 1.8% electronic nicotine delivery systems (ENDS) products. Daily smokers (25.1%) and nondaily smokers (34.9%) were the most likely to have tried at least one of these products, compared to former smokers (17.2%) and never smokers (7.7%), P<.001. 18.2% of young adults 18-24 and 12.8% of those >24 have tried one of these products, P<.01. In multivariable analysis, current daily (5.5, 4.3-7.6), nondaily (6.1, 4.0-9.3), and former smoking status (2.7, 2.1-3.6) remained significant, as did young adults (2.2, 1.6-3.0); males (3.5, 2.8-4.5); higher educational attainment; some college (2.7, 1.7-4.2); college degree (2.0, 1.3-3.3). Use of these products raises concerns about nonsmokers being at risk for nicotine dependence and current smokers maintaining their dependence. Greater awareness of emerging tobacco product prevalence and the high risk demographic user groups might inform efforts to determine appropriate public health policy and regulatory action.

The cost of healthcare procedures is continuously rising and more emphasis is being placed on increasing the quality and effectiveness of healthcare services. A combined total of 711,000 hip and knee arthroplasties are performed yearly. This figure is expected to increase to 4 million by the year 2030. The American Joint Replacement Registry has been developed to monitor the performance of devices, determine the cost-effectiveness of procedures, and increase patient safety for individuals in need of hip and knee replacement procedures.

The National Turfgrass Evaluation Program (NTEP) is a not‐for‐profit organization that facilitates the assessment of experimental and commercial turfgrasses for the turfgrass seed and sod industries in cooperation with university turfgrass scientists. The objective of this survey was to identify and compare common protocol and standards used by NTEP‐sponsored university scientists to aid NTEP staff in writing a document entitled Protocol and Standards for the Visual Field Assessment of Turfgrasses . Twelve NTEP‐sponsored university scientists were asked seven questions to ascertain the protocol and standards they used for the visual field assessment (VFA) of turfgrass quality. Collectively, scientists listed seven protocol categories and two or three options within each category. All scientists were aware of the definition of turfgrass quality, yet their ability to articulate all components of quality varied. The majority of scientists listed uniformity and density as the most important components of quality and one scientist each listed density and texture, density and color, or color as the most important. The majority of scientists used the 6 score as minimally acceptable quality and one scientist each listed 7, 5, or 4 as their minimally acceptable score. There were three methods used among scientist to determine a turfgrass quality score (1 to 9). Two methods used reference standards based on an idealized image and the other approach assigned a score based on a relative ranking without regard to a standard. All scientists stated that hosting NTEP trials was very important to their universities’ turfgrass research / teaching / extension programs.

OBJECTIVES: The vast majority of tobacco users began before the age of 21. Raising the tobacco sales age to 21 has the potential to reduce tobacco use initiation and progression to regular smoking. Our objective was to assess the level of public support nationally for 'Tobacco 21' initiatives in the USA. METHODS: The Social Climate Survey of Tobacco Control, a cross-sectional dual-frame survey representing national probability samples of adults was administered in 2013. Respondents were asked to state their agreement level with, 'The age to buy tobacco should be raised to 21.' RESULTS: Of 3245 respondents, 70.5% support raising the age to buy tobacco to 21. The majority of adults in every demographic and smoking status category supported raising the tobacco sales age to 21. In multivariable analyses, support was highest among never smokers, females, African-Americans and older adults. CONCLUSIONS: This national study demonstrates broad public support for raising the sales age of tobacco to 21 and will help facilitate wide dissemination of initiatives to increase the legal purchase age at national, state and local levels. Increasing public awareness about the susceptibility and rapid addiction of youth to nicotine may further increase public support for raising the tobacco sale age to 21.

RNA interference (RNAi), is a powerful new technology in the discovery of genetic sequence functions, and has become a valuable tool for functional genomics of cotton (Gossypium sp.). The rapid adoption of RNAi has replaced previous antisense technology. RNAi has aided in the discovery of function and biological roles of many key cotton genes involved in fiber development, fertility and somatic embryogenesis, resistance to important biotic and abiotic stresses, and oil and seed quality improvements as well as the key agronomic traits including yield and maturity. Here, we have comparatively reviewed seminal research efforts in previously used antisense approaches and currently applied breakthrough RNAi studies in cotton, analyzing developed RNAi methodologies, achievements, limitations, and future needs in functional characterizations of cotton genes. We also highlighted needed efforts in the development of RNAi-based cotton cultivars, and their safety and risk assessment, small and large-scale field trials, and commercialization.

Climate change is expected to alter the statistics of extreme events including rainfall storms, floods, droughts, and heatwaves. Climate-adaptive geotechnical structures warrant a quantitative assessment of the impacts of emerging and projected extreme patterns on the short and long-term behaviors of earthen structures. Furthermore, long-term changes to soil carbon and moisture due to non-extreme climate events should also be considered. While several large-scale studies have been conducted to evaluate various aspects of climate change, there is a clear gap in the state of knowledge in terms of assessing the resilience of geotechnical structures to changes in climatic trends (e.g., warmer climate, protracted droughts, intensified extreme precipitations, and sea level rise). The majority of the aforementioned climatic trends pose multi-physics problems involving thermo-hydro-mechanical (THM) processes in partially saturated soils and earthen structures. This review paper discusses how soil-atmospheric interactions and extreme event patterns in a changing climate can alter soil properties and loading conditions, affecting the performance of partially saturated geotechnical structures. We speculate how changes in climatic trends may weaken partially saturated earthen structures through strength reduction, drying, soil desiccation cracking, shrinkage, microbial oxidation of soil organic matter, fluctuation in the ground water table, land and surface erosion, and highly dynamic pore pressure changes. Each of these weakening processes is primarily induced by variations in the soil moisture and temperature. Finally, we discuss potential modes of failure imposed on partially saturated earthen structures by climatic trends.

A field experiment was conducted from 1986 to 1988 on a highly erodible soil in north Mississippi to study the effects of seven cotton ( Gossypium hirsutum L.) cropping systems on soil erosion, stand establishment, fruiting, earliness, and yield. Stand counts for no‐till cotton following hairy vetch ( Vicia villosa Roth ) averaged 30% less than for conventional tillage cotton. No significant difference in yield between cropping systems occurred in 1986. Yields in 1987 decreased as tillage intensity increased, but this trend was reversed in 1988. Rainfall distribution within each growing season contributed to the variability in yield and fruiting response to tillage and cover crops. In 1986, no‐till cotton following wheat ( Triticum aestivum L.) had 16 fruiting sites per plant as compared with 32 sites with conventional‐till cotton. Lower rates of abscision in cotton planted no‐till into wheat offset the reduced fruiting site production. Averaged over years, the number of fruiting sites on the four lower reproductive branchs (Nodes 5/2‐8) were 11% less with no‐till cotton following wheat than conventional‐till cotton. Cotton fruiting for no‐till with vetch or native winter cover was similar to reduced and conventional‐till cotton.

The phytohormones ethylene and auxin regulate many important processes in plants, including cell differentiation, cell expansion, and responses to abiotic stresses. These hormones also play important roles in many plant-pathogen interactions, including regulation of plant defense responses and symptom development. Sedentary plant-parasitic nematodes, which require the formation of a complex feeding site within the host root, are among the world’s most destructive plant pathogens. Nematode-induced feeding sites show dramatic changes in host cell morphology and gene expression. These changes are likely mediated, at least in part, by phytohormones. In the present review, current knowledge of the roles of ethylene and auxin will be explored in two main areas: the specific role of phytohormones in mediating feeding site development by plant-parasitic nematodes and the general role of phytohormones in affecting the ability of parasitic nematodes to cause disease.

The unique wide bandgap properties of SiC allow the creation of high performance normally-off vertical JFET power device. Due to the vertical nature of the device, it can easily be designed with blocking capability exceeding 2kV with R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS(ON), sp</sub> > 3mΩ-cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , resulting in the lowest specific on-resistance for enhancement mode SiC devices with V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">BR</sub> <; 1200V. The low R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS(ON), sp</sub> yields a small die size that translates into switching losses that are 5-10X smaller than similarly rated Si IGBTs. When used as an IGBT replacement, a significant reduction in losses can be achieved, greatly increasing the overall system efficiency of solar inverters and other renewable power systems.

Most wild and semi-wild species of the genus Gossypium are exhibit photoperiod-sensitive flowering. The wild germplasm cotton is a valuable source of genes for genetic improvement of modern cotton cultivars. A bi-parental cotton population segregating for photoperiodic flowering was developed by crossing a photoperiod insensitive irradiation mutant line with its pre-mutagenesis photoperiodic wild-type G. darwinii Watt genotype. Individuals from the F2 and F3 generations were grown with their parental lines and F1 hybrid progeny in the long day and short night summer condition (natural day-length) of Uzbekistan to evaluate photoperiod sensitivity, i.e., flowering-time during the seasons 2008-2009. Through genotyping the individuals of this bi-parental population segregating for flowering-time, linkage maps were constructed using 212 simple-sequence repeat (SSR) and three cleaved amplified polymorphic sequence (CAPS) markers. Six QTLs directly associated with flowering-time and photoperiodic flowering were discovered in the F2 population, whereas eight QTLs were identified in the F3 population. Two QTLs controlling photoperiodic flowering and duration of flowering were common in both populations. In silico annotations of the flanking DNA sequences of mapped SSRs from sequenced cotton (G. hirsutum L.) genome database has identified several potential 'candidate' genes that are known to be associated with regulation of flowering characteristics of plants. The outcome of this research will expand our understanding of the genetic and molecular mechanisms of photoperiodic flowering. Identified markers should be useful for marker-assisted selection in cotton breeding to improve early flowering characteristics.

productivity and the future of cotton breeding efforts tightly depend on 1) the level of the genetic diversity of cotton gene pools and 2) its effective exploitation in cotton breeding programs. Elucidating the details of genetic diversity is also very important to determine timeframe of cotton agronomy, develop a strategy for genetic gains in breeding, and conserve existing gene pools of cotton.

This research was conducted to develop relationships among evapotranspiration (ET), percolation (PERC), groundwater discharge to the stream (GWQ), and water table fluctuations through a modeling approach. The Soil and Water Assessment Tool (SWAT) hydrologic and crop models were applied in the Big Sunflower River watershed (BSRW; 7660 km(2) ) within the Yazoo River Basin of the Lower Mississippi River alluvial plain. Results of this study showed good to very good model performances with the coefficient of determination (R(2) ) and Nash-Sutcliffe efficiency (NSE) index from 0.4 to 0.9, respectively, during both hydrologic and crop model calibration and validation. An empirical relationship between ET, PERC, GWQ, and water table fluctuations was able to predict 64% of the water table variation of the alluvial plain in this study. Thematic maps were developed to identify areas with overuse of groundwater, which can help watershed managers to develop water resource programs.

This study proposes a low-cost and &#x201C;proof-of-concept&#x201D; methodology to obtain high spatial resolution soil moisture (SM) via processing reflected Global Positioning System (GPS) and a multispectral camera data acquired by small Unmanned Aircraft System (UAS) platforms. An SM estimation model is developed using a random forest (RF) machine-learning (ML) algorithm by combining features obtained from reflected GPS signals (collected by smartphones and commercial off the shelf receivers) in conjunction with ancillary vegetation indices from the multispectral camera data. The proposed ML algorithm uses <i>in-situ</i> SM measurements acquired via SM probes as labels. A preliminary field experiment was conducted on 210&#x00A0;m by 110&#x00A0;m (2.31 ha) crop fields (corn and cotton) in 2020 (from January to November, including crop planting through senescence time period) at Mississippi State University (MSU)&#x0027;s the heavily instrumented North Farm to acquire data needed for the ML model to train and test. Our results showed that both fields could be covered by GPS reflectometry measurements with about 13 minutes of flight time at a 15-m altitude, and SM can be mapped with 5m&#x00A0;&#x00D7;&#x00A0;5m spatial resolution (corresponding to the elongated first Fresnel zone). The model is trained with and validated against eight <i>in-situ</i> SM station datasets via 10-fold and leave-one-probe-out cross-validation techniques. Overall root-mean-square errors (RMSE) of 0.013 m <inline-formula><tex-math notation="LaTeX">$^{3}$</tex-math></inline-formula> m<inline-formula><tex-math notation="LaTeX">$^{-3}$</tex-math></inline-formula> volumetric SM and R-value of 0.95 [-] are obtained for 10-fold cross-validation. The proposed model reached an RMSE of 0.033 m <inline-formula><tex-math notation="LaTeX">$^{3}$</tex-math></inline-formula> m<inline-formula><tex-math notation="LaTeX">$^{-3}$</tex-math></inline-formula> and an R-value of 0.5 [-] in leave-one-probe-out cross-validation. While having limited data, the results indicate that high resolution SM measurement can be achieved with a low-cost GPS reflectometry system onboard a small UAS platform for use in precision agriculture (PA) applications.

OBJECTIVE: Paraspinal surface electromyographic (SEMG) scanning, utilizing post-style hand-held electrodes, was conducted to determine the usefulness of the technique as an assessment for myoelectric indicators of low back pain (LBP). A secondary objective was to correlate myoelectric abnormalities with other known outcome measures of the manipulable lesion. DESIGN: Blinded SEMG assessments with the patients standing upright, fully flexed and extended at the trunk, and measures of pressure pain thresholds (PPT) were made after four tests administered by another examiner. SETTING: The research was conducted on patients in a private chiropractic practice. PATIENTS: A convenience sample of 10 of the practitioner's most acute LBP patients without neurological deficit were asked to participate and none refused. Six patients without recent LBP volunteered as controls. MAIN OUTCOME MEASURES: Preset myoelectric indicators included: thoracolumbar asymmetry (T-L/A: first seen in an earlier pilot study), loss of flexion/relaxation (F/R) at L3, contralateral responsivity (increased myoelectric activity opposite the side of leg pain) and right/left asymmetry (R-L/A) at L3. RESULTS: Significant differences between groups were seen in T-L/A (p = .04) and R-L/A [data averaged from three postures (p = .04)], and robust group differences were seen in F/R (p = .011 right; p = .026 left). Contralateral responsivity was not significant. Loss of F/R was the only indicator that correlated with diminished PPT (r = .52 right; r = .46 left) and with Oswestry disability (r = .42), and that negatively correlated, as expected, with straight leg raising (r = -.50 right; r = -.74 left). CONCLUSIONS: Results support use of the technique to detect muscle dysfunction related to LBP. Further research of SEMG correlations with measures of the manipulable lesion is warranted.

Excellent performance and record inverter efficiency have been reported for 1200 V normally-off silicon carbide (SiC) vertical channel junction field effect transistors (VJFETs) with uniform channel doping. Optimally designed normally-off SiC VJFETs typically have a threshold voltage of approximately +1 V and pentode-like output characteristics with clear saturation. Some applications require significant surge or pulsed current capability thus it is desirable to increase saturation current density while maintaining normally-off operation. This paper reports the use of non-uniform channel doping in a normally-off SiC power VJFET to achieve a 28–48 % increase in saturation current and 13 % decrease in on-resistance compared to the uniform channel case. This results in a specific on-resistance of 2.5 mfl·cm2 and saturation current density of 1275 A·cm-2 at 25 °C. Forward drain leakage at V gs = 0 V and V ds = 1100 V (measurement setup limit) is very similar for both channel doping profiles and remains less than 55 uA (1.75 mA·cm−2) at 150 °C for the non-uniform channel SiC VJFET. The total switching energy for non-uniform channel devices was 194 (µ compared to 190 (jJ for uniform channel devices.

Although more on-farm storage ponds have been constructed in recent years to mitigate groundwater resources depletion in Mississippi, little effort has been devoted to estimating the ratio of on-farm water storage pond size to irrigated crop land based on pond metrics and its hydrogeological conditions. In this study, two simulation scenarios were chosen to determine such a ratio as well as to investigate pond hydrological processes using a Structural Thinking, Experimental Learning Laboratory with Animation (STELLA) model, one scenario with and the other without using pond water for irrigation for a typical pond that represented the average conditions in East Mississippi. Simulation results showed that pond water level changed moderately for conditions without using its water for irrigation, whereas pond water level changed dramatically for conditions with using its water for irrigation. A reasonable ratio of pond size to irrigated soybeans land was 1:18 if the irrigation rate was 2.54 cm/d (or 1 inch/d) and the low limit of the pond water level was drawn to near zero (0.08 m). For the ratio of 1:18, our simulations further revealed that a 1-ha soybeans land could save about 542 m3 groundwater each year. This study suggests that the STELLA model is a useful tool for estimating the ratio of pond size to irrigated crop land.

Abstract The reniform nematode ( Rotylenchulus reniformis ) is a sedentary semi-endoparasitic species that is pathogenic on many row crops, fruits, and vegetables. Here, the authors present a draft genome assembly of R . reniformis using small- and large-insert libraries sequenced on the Illumina GAIIx and MiSeq platforms.

The number of cotton (Gossypium hirsutum L.) plants being grown per unit of land area has gained attention due to the technology fees associated with seed containing value added traits. We investigated boll retention, yield, and yield components of cotton grown with reduced stands of 20% to 40% from the uniform planting pattern of four seeds per 30.5 cm of row. Five field experiments were conducted from 2012-2014 using eight treatments arranged in a randomized complete design with six replications. Yield and yield component data were collected. The plant one-row skip one-row treatment resulted in significant yield losses across all five experiments compared to the uniform planting pattern. Treatments with 20% stand reductions did not result in lower total yields; however, each plant in these treatments had to produce two additional bolls to maintain yield. Treatments which had at least 61 cm skips, 40% stand reduction, resulted in lower yields. Treatments had minor affects on boll weight, and lint percentage. The uniform planting pattern produced 67% of its yield from position one bolls compared to about 50% for treatments with reduced stands. Reduced stand treatments produced about 20% of their yield on monopodial branches compared to 10% for the uniform treatment. With modern precision planting equipments, opportunities exist to reduce seed rate and maintain yield; however, many production risk factors must also be considered before a reduced seeding rate is adopted.

Obesity is a growing public health concern that increases the risk of inflammatory and metabolic disorders. While the mechanisms linking obesity and metabolic disorders remain unknown, several studies suggest that alterations in lipid‐mediated metabolism play a significant role. The growing literature demonstrating the complexity of the plasma lipidome and its dysregulation within the context of several diseases has led to studies aimed at identifying lipid markers of obesity and/or type 2 diabetes. We assessed the effects of dietary fat and aging at the level of the lipidome using shotgun lipidomics with electrospray ionization‐mass spectrometry (ESI‐MS) and did so in females. Blood lipid profiles of female C57BL/6 mice following high‐fat diet (HFD) and low‐fat diet (LFD) consumption for short (6 weeks), long (22 weeks), and prolonged (36 weeks) periods were analyzed to evaluate the effects of HFD feeding. To compare lipid alterations with metabolic and liver regulation, we also examined glucose tolerance, insulin sensitivity, endocannabinoid levels, plasma esterase activity, and liver homeostasis. Multivariate analysis of blood lipidomic data indicated differences in the lipid profiles between HFD‐ and LFD‐fed mice with the most notable differences following 6 weeks of consumption. Age‐related alterations demonstrated the most striking effect on the lipidome where the most variation was observed between 6 week and 22–36 week treatment groups, irrespective of dietary treatment. Both HFD‐consumption and age altered the relative abundances of lipid species belonging to phospholipid, fatty acyl, and glycerolipid classes. Interestingly, HFD feeding also affected endocannabinoid levels in an age‐dependent manner. Plasma esterase activity was increased by HFD feeding at all time points, with the most pronounced effect following 6 weeks of consumption. Liver mRNA levels of three important metabolic regulators, PPARα, PPARγ, and CD36, were all affected by HFD consumption. These findings indicate an interaction between dietary fat consumption and aging with widespread effects on the blood lipidome, which may provide a basis for identification of female‐specific obesity‐ and age‐related lipid biomarkers. Support or Funding Information This project was supported in part with funds from the University of Georgia's Obesity Initiative ( http://obesity.ovpr.uga.edu/ ).

Allele specific (AS) SNP primers were developed for rapid detection of Fusarium oxysporum f.sp. vasinfectum (FOV) race 3. These primers were designed based on single nucleotide polymorphisms of partial sequence alignment of the β-tubulin (BT) gene from several FOV races. The primers showed high specificity for FOV race 3, and exclusively amplified PCR products from FOV race 3 DNAs and total genomic DNAs of FOV race 3-infected plant tissues. These primers did not produce any amplification products for races 1, 2, 4, 6, 7 and 8 of FOV or other FOV and Fusarium species from infected plant tissues. The assay is useful for specific and rapid detection of Fusarium oxysporum f. sp. vasinfectum race 3.