Online Master of Agricultural and Life Sciences

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https://hdl.handle.net/10919/51287

The Online Master of Agricultural and Life Sciences (OMALS), http://www.cals.vt.edu/online/, is uniquely positioned to meet the evolving and dynamic needs of today’s agricultural professionals. The program offers concentrations in the areas of agribusiness, applied animal behavior and welfare, applied nutrition and physical activity, education, environmental science, food safety and biosecurity, and leadership studies, as well as plant science and pest management. In addition to engaging classes, students benefit from the opportunity to work on-on-one with well-respected faculty in Virginia Tech's College of Agriculture and Life Sciences to complete a rigorous final project, using what they've learned and developing real-world research and communication skills. This collection showcases final projects completed by current and former OMALS students.

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Now showing 1 - 16 of 16

Biological watermelon (Citrullus lanatus L.) seed treatments for control of Acidovorax citrulli
Klein, Rachel (Virginia Tech, 2020-06-03)
Acidovorax citrulli is a seedborne pathogen responsible for bacterial fruit blotch (BFB), an economically important disease in melon and watermelon throughout the world. BFB is highly virulent and in affected fields can cause yield reduction of up to 95%, which has resulted in over $100,000 in losses to melon growers in some cases. The efficacy of green tea as an antimicrobial seed treatment against A. citrulli was tested. Watermelon seeds were treated with green tea after inoculation with transgenic A. citrulli expressing green fluorescent protein (GFP). Forty five percent of watermelon seedlings inoculated with a high level (OD600:1.0, ~8 x 108 cells/ml) of A. citrulli displayed GFP in their cotyledons. When these seeds were treated with green tea, only 11.2% displayed GFP in their cotyledons. None of the treated watermelon seedlings inoculated with a low level (OD600:0.001, ~8 x 105 cells/ml) of A. citrulli displayed GFP in their cotyledons. Green tea treatments effectively controlled the disease when administered as a liquid to infected watermelon seeds. Green tea has potential as an effective commercial treatment for pericarp infected seeds that could also be used by growers participating in the National Organic Program.
Bridging the CGMP Gap Between the U.S. Government, Academia, and the Food Industry
West, Joey (Virginia Tech, 2012-12)
In communication theory, one of the most important aspects is to always remember who the audience is at all times. In this case, the audience are members of the food industry who are expected to translate the knowledge of the CGMPs into practice. The goal of this research is twofold; to effectively communicate the need and nature of the CGMPs and to simply reconnect the regulations to the audience they were developed to assist. Further, a definition of perception is an individual’s capacity for comprehension. We find that in the real world, an individual’s comprehension does not always neatly fit inside the perimeters that the CGMPs provide. In some cases compliance with regulations does not allow for continuation of traditional processing methods, short-cuts, and individual bias when it comes to how firms may prepare, process, hold, and ship food products. That leaves it up to the government to find a means to bridge the gaps that exist between comprehension, perception, and reality. The main focus is to present information so that the ordinary person can understand and act upon the regulation on a consistent basis. The answer may lay not in the regulation itself, but Food Industry members’ ability to relate to and understand the need for compliance.
A Business Plan for a Norton Vineyard to be Established in Virginia
Sheldon, David R. (Virginia Tech, 2016-06-27)
This report specifically addresses the work and moneys required to set up from ground zero a vineyard totally devoted to raising Norton grapes to meet market need. It provides the thought process to determining a financially feasible vineyard, exhibits a year-to-year cash flow and income analysis as the vineyard reaches maximum revenue potential, and offers the information in a Business Plan format so that outside viewers can make their own objective conclusion regarding the profit potential of such a venture.
The effects of endophyte-infected tall fescue on production and reproductive performance parameters of beef cattle and calves
Anderson, Amber A. (Virginia Tech, 2019-12)
Beef cattle production records from two Virginia Department of Corrections herds from 2012- 2019 were analyzed to determine how the cultivar of tall fescue – toxic endophyte-infected or novel endophyte-infected – impacted cattle productivity metrics. Parameters compared were artificial insemination pregnancy rates, calving rates, body weights, and body condition scores of cows and birth weights and weaning weights of calves. The experimental design was a randomized completed block design with year as the replication. Samples of tall fescue were collected from the farm locations and tested for total ergot alkaloid concentrations. The samples from the farm with toxic endophyte-infected tall fescue all contained toxic levels of ergot alkaloids while the samples from the farm with novel endophyte-infected tall fescue indicated that half of the pastures at this location did not have toxic levels of total ergot alkaloids. Artificial insemination pregnancy rates were greater (P = 0.0011) for cows on novel endophyte-infected tall fescue (52 ± 1%) than for cows on toxic endophyte-infected tall fescue (43 ± 1%). Cows on novel endophyte-infected tall fescue had greater calving rates (94 ± 1%) than cows on toxic endophyte-infected tall fescue (89 ± 1%; P = 0.0243). Body condition scores and body weights at pre-breeding were greater for the cows on novel endophyte-infected tall fescue (P=0.0153 and P=0.0456, respectively). Birthweights were reduced for calves on toxic endophyte-infected tall fescue (34 ± 0.9 kg.) than for calves on novel endophyte-infected tall fescue (38 ± 1.4 kg.; P = 0.0257). Calves on novel endophyte-infected tall fescue had greater weaning weights (278 ± 5.9 kg.) than calves on the toxic endophyte-infected tall fescue (254 ± 5.9 kg.; P = 0.0217). Cattle production was improved on the farm with novel endophyte-infected tall fescue compared to cattle production on the farm with only toxic endophyte-infected tall fescue.
Efficacy of Organic Fungicides for Control of Powdery Mildew, Downy Mildew, and Plectosporium in Pumpkins
Simmons, Trevor; Baudoin, Antonius B.; Langston, David B.; Welbaum, Gregory E. (Virginia Tech, 2017-05-02)
Increased agritourism in the state of Virginia has led to an increase in the pumpkin planting acreage for pick-your-own operations across the commonwealth. Virginia pumpkin producers face yield losses from numerous sources, including several fungal diseases. The objective of this research was to compare the efficacy of certified organic fungicides against a conventional fungicide program for the control of powdery mildew, downy mildew, and plectosporium. Cultivar Warty Goblin pumpkins were grown in Rockville, Virginia during the 2016 crop season. Five different treatments (water, Kaligreen, Nordox, Regalia, and Bravo +Quintec/Proline) were assessed for their control of powdery mildew, downy mildew, and plectosporium. Disease observations and treatments were made weekly from August 12 – September 15. Disease ratings for powdery mildew showed that conventional fungicides provided the greatest control, with organic products Kaligreen and Nordox providing next-best control, statistically equivalent in some analyses. Regalia did not provide significantly better disease control than untreated water controls. Plectosporium disease severity was reduced the most in plots receiving conventional fungicides, with Nordox being almost as effective. Kaligreen provided no control of plectosporium. Regalia provided modest control, which in some analyses was significantly better than the untreated control. Downy mildew pressure was extremely limited, and no significant differences in disease incidence were seen among the treatments. In conclusion, several of the tested organic materials proved to be statistically as effective as the conventional fungicides in controlling both powdery mildew and plectosporium, although conventional fungicides provided numerically superior control for all diseases.
An H5N1 Pandemic: The Virginia Tech Campus as a Model of State, National, and Global Emergency Preparedness
Cornett, Rose (Virginia Tech, 2013-05)
Experts suggest the likelihood of another human influenza pandemic to be high, or maybe even inevitable. There’s a good chance that it could be H5N1, and the possible effects are worrisome. No one can know for sure when the next pandemic will occur. A pandemic has no regard for borders; once it begins, it has serious economic implications all levels. Organizations at all levels have put programs in place to prepare for such an event, and models allow them to better prepare by estimating illnesses, hospitalizations, deaths, and other factors pertinent to public health. Virginia Tech, a community in itself, will not be except from the fallout, and must ensure preparedness with regard to resources, expertise, and services in order to mitigate the effects of a full-blown pandemic.
Identification of the Lyme Disease Vectorin Southwest Virginia
Sheppard, James (Virginia Tech, 2009-05)
In the mid-1970s, fifty-one residents from the quaint little Atlantic seaside town of Lyme, Connecticut came down with something that resembled rheumatoid arthritis (Garrett, 1994). The ailment was dubbed Lyme disease and quickly spread to all fifty states. Once physicians became aware of the symptoms, the disease was diagnosed in many states of the Northeast, but there was a clear upward trend in Lyme disease found throughout the United States. By 1992, Lyme disease was the most reported vector-borne disease in the country (Steere, et al.). In fact, from 1995 to 2009, more than 300,000 cases of Lyme disease were reported to the Centers of Disease Control (CDC) by state health departments and the District of Columbia (http://www.cdc.gov/nc) (Appendix A). During this 14-year period, most of the cases were reported from northeastern states including Connecticut, Delaware, Massachusetts, Maryland, Minnesota, New Jersey, New York, Pennsylvania, and Rhode Island. In 1982, Lyme disease was first seen in Virginia and, following the nationwide trend, has steadily increased since that time (Lyme Disease, 2010b). The cases of Lyme disease in Virginia included 29,959 confirmed cases and 8,509 probable cases being reported just in 2009 (http://www.cdc.gov/nc).
John H. Kerr Dam and Reservoir: Ingredient in a Recipe for Disaster
Hood, Debra Gaye (Virginia Tech, 2010-04-30)
In today's world, dams have become possible bioterrorist tools to cause harm, destruction, and death. One such dam is the John H. Kerr Dam and Reservoir that was created to control flooding and produce hydroelectric power for parts of Virginia and North Carolina. A history of its development as well as its many benefits to the areas surrounding the facility in terms of wildlife habitats and its recreational uses will be discussed in addition to those involved with flood control, hydroelectric power, and drinking water supply. This paper will present scenarios of a possible threat from bioterrorists as well as the possibility of an accidental compromise to the John H. Kerr Reservoir. Responses by local, state, and federal agencies to both the accidental release of the herbicide atrazine and to the purposeful contamination with the radiological material, tritium, will be presented. Because these scenarios will eventually be published online as teaching tools, questions and answers based on the materials presented have been provided for that purpose.
Organic Oils as Seed Treatments for Soybeans to Inhibit Fungal Growth
Burgett, Alison (Virginia Tech, 2015-12-20)
Producing organic crops has become essential to satisfy the desires of the end consumer. To completely fulfill this task and meet the requirements of the National Organic Program in the U.S., the seeds planted must be organic. Seeds succumb to fungal infections without seed treatments. Organic seed treatments are not common. The purpose of this study is to test the ability of three organic oils (tea tree, coconut, and lemon) to act as organic seed treatments to inhibit fungal growth on soybean seeds that were badly infected with fungal disease. Each oil treatment was tested with three separate concentrations 10%, 50%, and 100%. The treatments were observed for 10 days and the results were recorded as a percentage of seeds infected with fungi. Both lemon oil and coconut oil at all concentrations failed to inhibit fungal growth. Tea tree oil at all three concentrations successfully prevented fungal infection on 100% of the seeds. The effective treatments show promise as organic seed treatments. Because of the positive results from the tea tree oil, it was further tested for germination and fungal inhibition on live soybean seeds at 2%, 5% and 10% concentrations. The treatments were observed for 12 days, and the results were recorded as a percentage of seeds infected with fungi. The germination rate and final germination percentage were also recorded. The 10% concentration inhibited a high percentage of fungi, but inhibited germination completely. The 2% and 5% concentrations had low germination percentages and mediocre fungal inhibition. The results from this research project show that there are still many options to explore in terms of organic seed treatments. Tea tree oil should be further tested in field studies, viability and vigor tests, and the germination study should be replicated at the 2% and 5% concentrations. Tea tree oil is effective against certain seed fungal contaminants, but also displays some phytotoxicity at low concentrations. Research should be completed to find tea tree oil’s effect on seedling emergence and early seedling growth. Tea tree oil could be effective in conjugation with other organic seeds treatments. Other essential oils that are produced organically should be tested against fungal control, and tea tree oil should be thoroughly tested and considered for cost effectiveness and possible health effects to farm workers.
Orographic Patterns Effect on Water Quality in the Shenandoah National Park
Wood, William Douglas (Virginia Tech, 2009-12-04)
With the onslaught of the “Green Revolution” environmental issues have taken center stage. Now much of this onslaught is focused on Carbon dioxide and climate change, but what is overlooked many times over are the synergistic effects associated with issues. Many factors influence a particular environment’s response and reaction to particular pollutants.
Plant Health Safeguarding Continuum in the United States
Jennings, Shenell F. (Virginia Tech, 2010-12-02)
Every traveler and all goods entering our country’s borders is a potential pathway for harmful exotic plant pests. Plant pests include plant feeding insects, mites, snails, slugs, and plant pathogens capable of causing millions of dollars in damage to U.S. agriculture and natural resources. Here in the U.S. with the increasingly high volume of human-facilitated movement of goods and travelers, the magnitude of the task of minimizing the risk of invasive pests entering the country and managing pest incursions is challenging. This course will familiarize individuals with current issues, policies, and existing safeguards to prevent the spread of invasive pests. The course consist of eight lesson contained in two modules: (1) Introduction to Plant Protection and Quarantine and (2) Framework for Plant Protection and Quarantine. The first module (Intro to PPQ) consists of: (1) Plant Protection and Quarantine (2) Federal Government Role in PPQ (3) Legal Authority and (4) International Obligations. The second module (Framework for PPQ) consists of: (1) Prevention (2) Preparedness (3) Response (4) Recovery.
Potential Impact Of Regalia® Treatments On Tree Health And Vigor
Yelvington, Alan L. (Virginia Tech, 2018-06-14)
Regalia®, an extract from giant knotweed (Reynoutria sachalinensis (REYSA)), is an organic immune system response (ISR) treatment that can mitigate fungal and bacterial infections by stimulating the genetic immune response system of a plant. The mode-of-action of Regalia® is to penetrate the plant tissue and stimulate a biodynamic response to resist pathogens. The primary response to Regalia® is the production of reactive oxygen species (ROS) that disable pathogens, and a thickening of cell walls to inhibit pathogen penetration. Regalia® is an uncommon fungicide since the protection is provided by the plant itself and not directly by the agent, and because the activity is internal rather than external. This process provides protection from pathogens that get past surface protectants. Because ISR agents require plant resources to be effective, there is a risk that they can disrupt the metabolic processes of the plant, or there can be an allocation cost that could diminish the plant vigor. This study examines if the ISR activity of Regalia® presents any phytoxicity or impact to vigor in four varieties of cider apples (Malus ×domestica cvs. Dabinett, Medaille d’Or, Chisel Jersey, and Redfield). This quantitative study, based on measured metrics of plant growth during the study period, showed that Regalia, applied with Cueva or Serenade, had no effect on primary or secondary shoot length or the number of shoot leaves on any of the four test varieties.
Response of Septoria (Zymoseptoria tritici) isolates with Qi and Qo mutations under multiple fungicide selection
Howard, Jaema (Virginia Tech, 2024-05-08)
Inatreq, active ingredient fenpicoxamid, is a new QiI fungicide product brought to the market by Corteva Agriscience for strong activity against Septoria (Z. tritici). This study examines the interaction between Qo and Qi mutant Septoria isolates to confirm negative cross-resistance between the two sites. And to observe the change in sensitivity of the isolates in a mixed population over several generations and under multiple rates of fungicide selection. Initial growth rate and fitness isolates were determined for four isolate strains; wildtype (IPO323), G37V single mutation (WF.2.44), G143A single mutation (37- 16), and G37V-G143A double mutation (716.3F.2.2). Initial IC50 values were determined for several fungicides in multiple fungicide groups, QiIs, QoIs, Azoles, SDHIs to confirm negative cross-resistance and determine concentrations needed for fungicide treatments. A mixed population trial was then conducted with a 6-rate dose response for three fungicide treatments; Inatreq (QiI), pyraclostrobin (QoI), and a 1:1 mix of Inatreq and pyraclostrobin. It was suspected that throughout 6 generations, sensitivity of single mutant isolates to the opposite fungicide site inhibitor would increase. The double mutation isolate would become more sensitive under fungicide selection than the single mutant isolates. The results of the study confirmed this hypothesis of negative cross-resistance between fungicide groups. Qo single mutant isolate was determined resistant to QoI fungicide but sensitive to QiI fungicides, and the opposite found true for the Qi single mutant. The double mutant isolate was sensitive to both fungicide groups, with increased sensitivity than the single mutants. Under double fungicide selection, all mutant strains were sensitive to the treatment, with increased sensitivity than under single fungicide selection.
Sensitivity of Colletotrichum orbiculare Isolates in Virginia Watermelon to Thiophanate-methyl, Pyraclostrobin, and Prothioconazole
Byrd-Masters, Linda C. (Virginia Tech, 2018-05-04)
Fungicide resistance development is a major concern for growers due to the limited modes of action available and the limited number of applications that can be used in the field. Determining sensitivity to fungicides and assessing risk of resistance is vital to the development of future chemistries necessary to inhibit or control pathogens. One common simple in vitro method of measuring sensitivity to fungicides is measuring radial growth of a pathogen exposed to multiple doses of fungicides in fungicide-amended agar to determine EC50 which is the concentration of fungicide that provides 50% inhibition of the isolate as compared to a non-fungicide-amended control. Colletotrichum orbiculare (syn. C. lagenaria) is the causal organism for anthracnose of cucurbits. Thiophanate-methyl and pyraclostrobin are common fungicides used to manage anthracnose in cucurbit crops. Prothioconazole, is labeled for use in cucurbits but not specifically recommended for management of anthracnose; however, control of anthracnose with fungicides containing this active ingredient has been observed in the field. A mycelial growth assay was conducted using fourteen C. orbiculare isolates collected from watermelon (Citrullus lanatus) in Southampton County, Virginia. Isolates were incubated on fungicide-amended PDA at fungicide concentrations 0 – 100 µg/mL of each fungicide, and the diameter of fungal growth on fungicide-amended and non-amended media was measured and compared to determine percentage of growth reduction. There was little variation in the fungicide sensitivity profiles of the fourteen isolates examined. Overall they were highly sensitive to pyraclostrobin (EC50 <0.1 µg/mL), and insensitive to thiophanate-methyl (EC50 > 1 µg/mL) and prothioconazole (EC50 > 100 µg/mL).
Survey of Powdery Mildew and Gray Mold Disease Management in Virginia and North Carolina Cut Flower Farms
Rock, Shana (Virginia Tech, 2019-12-26)
Powdery mildew and gray mold diseases have potential to cause significant economic losses to cut flower growers. Information is needed on the effects of these diseases on growers’ returns and the effectiveness of practices to control the diseases. A survey was conducted to examine powdery mildew and gray mold disease management practices on cut flower farms in North Carolina and Virginia. Twenty cut flower farmers completed an online survey and eight of those respondents also participated in an interview. The survey gathered information about the farms, such as its acreage and number of years growing cut flowers, flower genera affected by the diseases, fungicide use and efficiency, and cultural control use and efficiency. The survey and subsequent interviews provided several major findings. First, the floral genera most affected by powdery mildew in North Carolina and Virginia were Zinnia, followed by Dahlia. The genera most affected by gray mold were Ranunculus, followed by Anemone and Dahlia. Second, crop loss due to each disease was mostly at the 0 to 10% level, with one farm losing 91 to 100% of Phlox crops to powdery mildew and another losing 81 to 90% of Tulipa crops to gray mold. Third, 40% of respondents have not used any fungicides for disease management; and for those who have, neem oil was the product they used most frequently. Fourth, all respondents considered sustainability very important when making disease management decisions; this was supported by their extensive use of cultural practices for disease control, in addition to their preference of nonchemical approaches and biorational products over synthetic pesticides. The commonly used cultural controls included, crop rotation, proper watering, disease resistant cultivars, sanitation, proper spacing, and weeding. Findings from this survey will help cut flowers growers in the Mid-Atlantic region to better manage these two important diseases.
A Survey of Production and Pest Management Strategies Used For Gooseberry Production Throughout Three Regions of the United States
Johnson, Linda Putnam (Virginia Tech, 2010-08-13)
Twenty-one gooseberry growers, of all sizes, and from three different regions of the United States were surveyed to learn about their production and pest management practices. Growers were interviewed, to identify and understand the pest strategies used today. The data gathered was compiled and analyzed to determine correlations and to determine areas of biological and cultural control of pests where further experimental research is needed. Since Ribes hiretellum Michaux (American Gooseberry) and Ribes uva-crispa L. (European Gooseberry) are considered a minor berry crop in most states, there is little attention given to integrated pest management for them. There are pest issues facing both large and small gooseberry growers, especially the misidentified small gooseberry sawfly, in the Northeast and the Pacific Flatheaded Borer, in the Pacific Northwest. Some smaller growers are reluctant to use pesticides on their crops Recommendations are presented for areas of further field and laboratory testing to be done in the increased use of beneficial insects and also in creating natural habitats for these beneficial to cohabitate, such as “beetle banks”. This study serves as a general pest management resource for gooseberry growers that reveals current pest issues and also proposes candidates for additional biological control measures for problem gooseberry pests.

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Browsing Online Master of Agricultural and Life Sciences by Department "Plant Pathology, Physiology, and Weed Science"

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