Scholarly Works, School of Plant and Environmental Sciences
Permanent URI for this collection
Browse
Browsing Scholarly Works, School of Plant and Environmental Sciences by Content Type "Conference proceeding"
Now showing 1 - 12 of 12
Results Per Page
Sort Options
- Application of Fourier Transform Infrared Spectroscopy for Detection of Bacterial Fruit Blotch DiseaseMargenot, Andrew J.; Parikh, Sanjai J.; Zhao, Bingyu Y.; Walcott, Ronald R.; Welbaum, Gregory E. (2017-09-13)Bacterial fruit blotch (BFB), caused by Acidovorax citrulli affects the production of cucurbits worldwide, and causes substantial economic losses. Since cucurbit seeds are the most important source of inoculum for BFB outbreaks, seed health testing is an important component of disease management. Currently, there are no nondestructive assays that are sensitive enough to reliably detect A. citrulli-infected seeds. Fourier transform infrared spectroscopy (FTIR) may provide the sensitivity necessary to detect A. citrulli-infected seeds. Attenuated total reflectance (ATR) FTIR was evaluated for the detection of watermelon seeds infected with A. citrulli by pistil inoculation. A. citrulli cells produced a unique signature at a detection limit of approximately 105 cfu/mL. Infected, dry watermelon seeds whose embryos were infected with A. citrulli produced a different spectral profile compared to non-infected seeds. Spectral subtractions between infected and non-infected seeds suggest the potential for indirect detection of A. citrulli by altered ester C-O absorbance bands. Principal component analysis (PCA) of seeds infected with bacterial concentrations ranging from 0.001 – 0.1 OD demonstrated potential for multivariate detection of infected seeds at intermediate contamination levels (0.01 OD) relative to non-infected seeds. This separation was driven by high loading of ester C-O absorbance at frequencies ranging from 1120 - 1000 cm-1, though absorbances identified in pure A. citrulli culture were not observed. These results suggest that FTIR can be used to nondestructively detect seeds infected with moderate levels (105 cfu/mL) of A. citrulli infection.
- Changes in Fluvial Erosion of Cohesive Streambank Soils with Stream ChemistryThompson, Theresa M.; Akinola, Akinrotimi I.; Hoomehr, Siavash; Eick, Matthew J. (2018-06-01)The goal of this study was to quantify changes in fluvial erosion rates with changes in stream chemistry.
- A comparison of gradient table, field, and paper towel germination tests of melon (Cucumis melo L.) seedsWelbaum, Gregory E. (2021-11-16)
- Does NDVI consistently assess plant response to herbicides?Koo, Daewon; Vahidi, Milad; Gonçalves, Clebson G.; Peppers, John M.; Shafian, Sanaz; Askew, Shawn D. (2022-11-08)
- Effects of Boron Fertilization on Peanut Seed Germination Tested in a Lab Field (TM) TableBenton, Anna; Balota, Maria; Welbaum, Gregory E. (2017-09-11)EFFECTS OF BORON FERTILIZATION ON PEANUT SEED GERMINATION TESTED IN A LAB FIELD TABLE Benton A.1, Balota M.1, Welbaum G. E.2 1 Department of Plant Pathology, Physiology, and Weed Science, 2 Department of Horticulture, Virginia Tech, Blacksburg, VA, USA Contact: Greg Welbaum, welbaum@vt.edu Peanut (Arachis hypogaea L.) is an important crop for eastern Virginia (VA) and North Carolina (NC) where it thrives in sandy soils. Boron (B) is not retained in these soils, and seeds with <13mg kg-1 B may have hollow heart and reduced seed quality. Therefore, B is routinely applied as fertilizer regardless of soil test results to prevent deficiencies in peanut seed crops but may contribute to water pollution. A mixture of two market types and newer and older cultivars of peanuts were fertilized with 0, 0.6, 1.1kg ha-1 B at the Tidewater Agriculture Research and Extension Center. Seeds were germinated in sand on a Lab Field table to simulate soil conditions in Eastern VA and NC fields. The peanuts were hand planted on the Lab Field table maintained at a constant sand temperature of 25°C. Mean time to germination (MTG) and germination percentage were recorded to compare treatments. There were no differences in MTG or germination percentage between fertilized and unfertilized plants, market types, or newer and older commercial cultivars on the Lab Field table. Based on this research, B fertilization in the VA and NC production region is not necessary to produce a high quality vigorous peanut seed. The Lab Field table was an effective tool for testing germination under simulated field conditions.
- Innovative Cover Cropping Systems for Sandy Loam Soils in the Mid-Atlantic Region, USAReiter, Mark S.; Wolters, B. R.; Lawrence, C. E. (2018-09-25)
- LabField™ as a Tool for Predicting Field Emergence of Diverse Melon GenotypesWelbaum, Gregory E. (2021-04-22)Many vegetables have specific climatic requirements with relatively narrow temperature and moisture optima for best establishment and production. Global climate change threatens food crop production in some areas because of shifts in temperature and moisture distribution. Identifying germplasm with greater environmental adaptability will help sustain global vegetable production. LabFieldTM tables were developed to test seed germination and plant growth in soil maintained at constant temperature or along a gradient of temperatures in a laboratory. The LabFieldTM eliminates using multiple growth chambers to test the same broad range of environments. In this study, we compared field emergence of five melon (Cucumis melo L.) with emergence of the same genotypes on a LabFieldTM table and using standardized Association of Official Seed Analysts germination tests on paper towels. The objectives were to identify genetic variation in germination performance and to test LabFieldTM as a tool for accurately predicting field emergence.
- The Production and Function of Mucilage by Sweet Basil (Ocimum basilicum L.) SeedWelbaum, Gregory E.; Barney, Jacob; Zhou, Dongfang (2017-09-12)Sweet basil (Ocimum basilicumL.) seeds produce a thick layer of mucilage around the testa within minutes after hydration. Mucilage is most prevalent among plant species adapted to surviving in arid sandy soils, though its significance in determining the ecological fitness is unclear. The mucilage produced by these seeds is reported to be composed of cell-wall polysaccharides that are deposited in testa cells during development. In this study, sweet basil seeds were examined using light and environmental scanning electron microscopy. The mucilage of basil seeds is held together by columnar structures that unfolded from the pericarp and helped hold and stabilize the mucilage to the seed surface. The mucilage was removedusing diluted hydrochloric acid to compare performance of seeds with and without mucilage. Mucilage removal inhibited laboratory seed germination under ideal conditions and significantly reduced the seed water content four fold. The mucilage anchored seeds and increased their resistance to movement in the environment. Osmometry showed the water potential of fully hydrated seeds to be near zero suggesting that the mucilage provides a pool of loosely bound water to germinating seeds and seedlings in arid environments. Testing in soil with various levels of hydration confirmed intact basil seeds with mucilage germinated to higher percentages and survived longer than seed with mucilage removed.
- Response of Retail Lawn Seed Products during Acute Drought and RecoveryBreuillin-Sessoms, Florence; Petrella, Dominic P.; Sandor, Daniel; Bauer, Samuel J.; Horgan, Brian P. (American Society for Horticultural Science, 2021-08-01)Consumers often have multiple choices when purchasing retail lawn products in stores. In this study, we evaluated the acute drought performance of locally available retail lawn seed products (mixtures or blends) at two mowing heights of 2.5 and 3 inches. We hypothesized that the species present in the products and the height-of-cut differentially influence the drought resistance and recovery of the mixtures and blends. In Fall 2016 and 2017, 28 different products consisting of 25 mixtures and 3 blends of turfgrass seeds were established under a fully automated rainout shelter at the St. Paul campus of the University of Minnesota. The drought treatments lasted for 67 days in 2017, and 52 days in 2018; both the 2017 and 2018 treatments were followed by a recovery period. Data were obtained during acute drought treatments and recovery periods for visual turfgrass quality and green turfgrass cover using digital images of the plots. During the first year, several products displayed higher green stability (or the ability to remain green) at the 3-inch height-of-cut compared with the 2.5-inch height-of-cut. Products with tall fescue (Schedonorus arundinaceus) and fine fescue (Festuca sp.) as dominant species generally performed better during the drought treatments, whereas an increasing presence of perennial ryegrass (Lolium perenne) and kentucky bluegrass (Poa pratensis) decreased the visual drought performance of the products. During the recovery period, an effect of the interaction between mowing height and the date of data collection on the percentage of green cover was observed: the lower mowing height improved the early recovery of green cover after acute drought. These findings suggest that consumers in the upper midwestern United States and areas with a climate similar climate to that of St. Paul, MN, who are challenged with multiple choices of lawn seed products should choose products containing a higher tall fescue content and adjust their mowing heights to optimize recovery.
- Silvopastures: SVAREC update, Kentland results, and SPAREC studiesPent, Gabriel J.; Fike, John H.; Downing, Adam K. (2017-08-02)Silvopasture is the purposeful and managed integration of trees, forages, and livestock. With appropriate management, these intensive, integrated management systems create beneficial interactions among the system components that result in more efficient resource use and greater economic output over the life of the system. Benefits of silvopastures can include increased forage yield or quality, reduced animal stress, improved tree growth and quality, greater farm product and ecosystem diversity and a number of conservation gains (Fike et al. 2004)
- Understanding Data Science Instruction in Multiple STEM DisciplinesSnyder, Caitlin; Asamen, Dawit M.; Naseri, Mohammad Y.; Aryal, Niroj; Biswas, Gautam; Dubey, Abhishek; Henrick, Erin; Hotchkiss, Erin R.; Jha, Manoj K.; Jiang, Steven X.; Kern, Emily C.; Lohani, Vinod K.; Marston, Landon T.; Vanags, Christopher P.; Xia, Kang (2021-07)As technology advances, data driven work is becoming increasingly important across all disciplines. Data science is an emerging field that encompasses a large array of topics including data collection, data preprocessing, data visualization, and data analysis using statistical and machine learning methods. As undergraduates enter the workforce in the future, they will need to “benefit from a fundamental awareness of and competence in data science”[9]. This project has formed a research practice partnership that brings together STEM+C instructors and researchers from three universities and an education research and consulting group. We aim to use high frequency monitoring data collected from real-world systems to develop and implement an interdisciplinary approach to enable undergraduate students to develop an understanding of data science concepts through individual STEM disciplines that include engineering, computer science, environmental science, and biology. In this paper, we perform an initial exploratory analysis on how data science topics are introduced into the different courses, with the ultimate goal of understanding how instructional modules and accompanying assessments can be developed for multidisciplinary use. We analyze information collected from instructor interviews and surveys, student surveys, and assessments from five undergraduate courses (243 students) at the three universities to understand aspects of data science curricula that are common across disciplines. Using a qualitative approach, we find commonalities in data science instruction and assessment components across the disciplines. This includes topical content, data sources, pedagogical approaches, and assessment design. Preliminary analyses of instructor interviews also suggest factors that affect the content taught and the assessment material across the five courses. These factors include class size, students’ year of study, students’ reasons for taking class, and students’ background expertise and knowledge. These findings indicate the challenges in developing data modules for multidisciplinary use. We hope that the analysis and reflections on our initial offerings has improved our understanding of these challenges, and how we may address them when designing future data science teaching modules. These are the first steps in a design-based approach to developing data science modules that may be offered across multiple courses.
- Virginia Report: Seed Research Activities in Virginia for 2021Welbaum, Gregory E. (2021-10-15)