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Agricultural Science
Helping Agriclutural Production to Flourish
Safe, sustainable agricultural systems that are socially, economically, and environmentally responsible are key to enhancing the lives of Tennesseans and supporting a growing global population. We are exploring ways to deliver discoveries using a systems approach to agriculture productivity that will provide customizable solutions for producers.
Crop Science
Genetic Resources and Single Gamete Profiling of Sweet Sorghum as a Biofuel Crop
Developing Grain Amaranth and Legume Crops
Unmanned Aerial Vehicle (UAV) Applications for Precision Agriculture
Mitigating Plant Disease Through Understanding of the Disease Process
Increasing Agricultural Production Knowledge for Stakeholders
Industrial Hemp Research and Extension
Using Biotechnology to Engineer Agricultural Crops with Improved Seed and Vegetable Oils Production
Gene Editing and Functional Genetics to Improve Legume Nitrogen Acquisition
Germplasm Enhancement in Soybean Using Novel Molecular Tools and Techniques
Climate-smart Practices and Tools for Enhancing Agricultural Productivity, Profitability, and Sustainability
Research and Applications in Biotechnology to Enhance Plant Productivity Against Worsening Environmental Conditions
Specialty Crops
Entomology and Chemical Ecology
Promoting Integrated Pest Management in Tennessee
Disease Management in Nursery Cropping Systems
International, Alterative, and Niche Fruit and Vegetable Crops for Small Farm Producers
Sensing and Robotic Technologies for Nursery Crop Production
Microbial-based IPM as a Tool for Sustainable Crop Production
Organic Agriculture Research, Extension and Education Program
Invasive and Key Insect Pest Management in Nursery Cropping Systems
Crop and Site-Specific Nutrient Management for Sustainable Crop Production
Nursery Production and Sustainability - Improving Profitability and Reducing Inputs in Nursery Crop Production
Crop Science
Genetic Resources and Single Gamete Profiling of Sweet Sorghum as a Biofuel Crop
Dr. Ahmad Naseer Aziz
Situation:
Sweet sorghum, which is suitable to hot and dry environments, and its dedication as energy crop also allows food and feed usages while being incorporated into Tennessee small-farm production systems. Biofuel feedstock production related research efforts will be facilitated by developing sorghum genetic resources and assessment tools based on marker systems for individual cells.
Activity:
Through this project, documented data on sorghum spikelets after flag leaf emergence during microspore maturation was collected for accurate harvest per predictive dates. Research samples of free microspores at uninucleate to early binucleate stages were obtained from sessile anthers at appropriate sizes, which were then successfully cryopreserved. Multiple Displacement Amplifications were used to enhance genomic DNAs from individually isolated microspores for analyses with molecular markers related to sugar production traits. The genetic marker amplification success rate among microspores was found to be 89% while confirming about 21% parental alleles. For accessing sorghum genetic resources and providing educational trainings, extension agents and schoolteachers across Tennessee counties were contacted.
Impact:
By establishing innovative protocols for genetic enhancement of sweet sorghum, which has been traditionally grown by Tennessee small farmers, its further realized as potential dedicated U.S. biofuel crop. Sweet sorghum breeding endeavors were facilitated by analyzing the immature pollen grain DNAs towards unbiased and 100% inclusive genetic analyses. Public information was made for available by research presentations to facilitate downstream molecular genetic analyses without maintaining large breeding populations. Educational resources were also facilitated while expanding research partnerships with the U.S. National Plant Germplasm System Research Unit as well as USDA-ARS Wheat, Sorghum and Forage Research Unit.
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Developing Grain Amaranth and Legume Crops
Dr. Matthew W. Blair
Situation:
Lack of plant differentiation in agricultural systems of the Southeastern USA increases threats of disease epidemics, insect outbreaks or crop failure in heat waves and drought. Good crop rotations can increase adaptation to climate variability. Alternative crops are needed for system stability. Creating new row crops will help farms facing multiple stresses of pathogens, pests, dry weather, degraded soils, monocropping and volatile international markets. We develop alternative grains for this purpose.
Activities:
(1) release of grain amaranth and legume varieties (2) fertilizer and photosynthesis evaluation trials (4) sequencing of legume RNA under stress (4) experiential research in plant breeding, physiology and molecular genetics for undergraduate and graduate students. Laboratory-based research emphasizes marker-assisted breeding. Biotechnology and genomics tools are applied to grain crops including high throughput DNA sequencing, and transcriptomics.
Impact:
The benefits to stakeholders generated by this project are multiple: including released germplasm, fertilizer recommendations, scientific publications, graduate student thesis, undergraduate projects, extension pamphlets, meeting presentations, field days, small farm expos and in-person/virtual conferences (e.g. www.amaranthinstitute.org). Pioneering biofortification (nutritional breeding) for micronutrient quality in amaranth, dry beans, cowpeas and mung beans. Laboratory uses molecular biology tools in cultivar development, with agronomic and physiological testing techniques. Re-sequencing and genome wide association important. Phenotyping with four farm and canning groups in the state (Agricenter in Memphis, Bush Bros. Beans Inc. in Knoxville, Caney Fork Farms in Carthage, and Green Door Gourmet organics in Nashville). Germplasm development and exchange in collaboration with multiple African, Asian, European and US groups.
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Unmanned Aerial Vehicle (UAV) Applications for Precision Agriculture
Dr. Anjin Chang
Situation:
Precision agriculture has become one of the most important technologies in recent decades, with unmanned aerial vehicles (UAVs), also known as drones, making it easier to collect high-quality images that are unobtainable by conventional platforms such as airborne and space-borne. The data collected by UAVs can be analyzed and used by researchers to improve their experiments for various applications, and by farmers to make informed decisions about how to manage their farms.
Activity:
The program is developing UAV-based high-throughput phenotyping (HTP), which includes protocols for data collection, processing, and analysis. Mosaic images and height maps are generated from raw UAV images using Structure from Motion (SfM). Plant or plot-based attributes, such as canopy cover, canopy height, and vegetation indices, are extracted and combined with field sampling data for crop monitoring, yield prediction, disease detection, crop management system, etc.
Impacts:
The output from the program helps researchers and stakeholders to work more efficiently. UAVs, as a cutting-edge technology, can be used in research programs such as breeding, soil analysis, and modeling, while producers can use the technology to optimize their crop management decisions. By using UAVs to create valuable geospatial data for precision agriculture, more resources such as fertilizers, pesticides, and water can be saved. Additionally, precision agriculture offers a promising approach to sustainable agriculture and climate change adaptation.
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Mitigating Plant Disease Through Understanding of the Disease Process
Dr. C. Korsi Dumenyo
Situation:
As the world population approaches eight billion inhabitants, a corresponding increase in food production is required to feed this increasing population. Among other factors such as political instability, market volatility, plant disease, compounded by climate change and shrinking arable lands, is a major threat to global food production costing the US economy an estimated $33 billion annually through yield loss, disease control and environmental damage. Our research is focused on unearthing the molecular secrets in plant-bacterial interactions that result in two important diseases of vegetables – bacterial soft rot of all vegetables and bacterial wilt of cucurbits crops.
Activity:
We are using biochemical, genetic and genomic approaches to a) characterize both the plant and pathogen genetic elements involved in the disease, b) identify resistant host genotypes for incorporation into breeding programs, c) characterizing the chemical signaling process during disease and d) seek sustainable approaches to managing the diseases.
Impact:
We have sequenced the genomes of rotting and wilting pathogens, characterized bacterial genes which are deployed during the infection of plants, are characterizing plant chemical constituents which signal to the pathogen the presence of the plant, and have identified muskmelon accessions resistant to wilt disease and which can be employed in a breeding program for resistance cultivars. This research has advanced the body of knowledge on soft rot and cucumber wilt diseases through research publications and presentations and trained undergraduate and graduate students. Future benefits include improved disease resistant cultivars and a higher output from US and global agricultural operations.
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Increasing Agricultural Production Knowledge for Stakeholders
Dr. Jason deKoff
Situation:
(1) Winter canola is a potential cover crop and cash crop for farmers that can be rotated with winter wheat and reduce erosion. It can also be used by producers in the on-farm production of their own biodiesel. There is little research information on winter canola production in southeastern U.S. available for farmers. (2) Drone technology is a new tool that can be used in agriculture, however, few stakeholders have knowledge about its potential.
Activity:
(1) Winter canola variety trials were planted as part of the National Winter Canola Variety Trial to measure yield, seed oil, seed protein, pollinators, and soil cover potential. (2) Drone workshops for farmers were held in six Tennessee counties, a fact sheet on using drones in animal production was developed, and drone certification training was provided to agricultural staff through the American Society of Agronomy.
Impact:
(1) Results indicated that insects from six different orders and 47 different families were collected using multiple trapping methods while canola plants were in full bloom. Results also indicated open-pollinated varieties produced a greater number of plants than hybrid varieties by 5 weeks after planting, however, open-pollinated varieties had greater winter mortality. (2) 96% of county workshop participants increased their knowledge of using drones in agriculture. 47% indicated an increased interest in purchasing a drone in the next 2 years. 40 agricultural staff members were trained for the drone certification exam. The fact sheet received a first place award from the Tennessee Association of Agricultural Agents and Specialists.
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Industrial Hemp Research and Extension
Dr. Emmanuel Omondi
Situation:
There continues to be great and growing interest of US farmers in growing industrial hemp after its recent removal from the federal government’s list of controlled substances in the 2018 Farm Bill. However, previously unforeseen legislative, production, and market challenges have resulted in substantial dissipation of the initial enthusiasm. Knowledge needed to grow hemp has largely been lost in the 70 years it has not been grown. Tremendous challenges faced by growers include compliance with changing regulations, control of diseases, pests and weeds, acquisition of the correct genetics for our environment, and many other issues. Intensive research on recommended varieties for a particular region, best management agronomic practices, and marketing information is therefore urgently required.
Activity:
A needs assessment survey was undertaken with all 95 extension agents in the state. This information was used to develop a comprehensive research project plan on best management practices including cultivar selection, integration of hemp into typical cropping systems, location and planting date effects, pest and disease control, as well as an assessment of supply chain dynamics. Research results will be disseminated through direct extension agent training, workshops, field days, and publications.
Impacts:
Adoption of promising/profitable cultivars, revived interest in CBD hemp and new interest in fiber and grain hemp, establishment of comprehensive supply chain and marketing outlets, and increased understanding of supply chain and market dynamics (by at least 75% of trained extension agents and growers). Other impacts include establishment of a comprehensive grower and academic curriculum on industrial hemp, regular in-service training for extension agents, at least 5 annual workshops for producers throughout Tennessee, and at least one digital fact sheet published.
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Using Biotechnology to Engineer Agricultural Crops with Improved Seed and
Vegetable Oils Production
Dr. Christine A. Ondzighi-Assoume
Situation:
The program addresses the question/problem of the mass production of new cultivar soybeans with high nutritional values in the US.
Activity:
Activities include using a state-of-art-technology CRISPR-Cas9 and cell and tissue culture systems to address this problem. We will create mutant lines of soybean that produce increased amounts of oils.
Impact:
The results related to the establishment of soybean cell culture systems capable of genetic transformation are under publication. Knowing that soybean is recalcitrant to genetic manipulation, this has always been an obstacle in soybean breeding. These results are promising accomplishments for soybean cell cultures. The method developed in this program will save stakeholders money and time. Instead of taking a full year and a half to generate new soybean cultivars, the established procedure will take 7-8 months to obtain new and improved soybean plants. This procedure has been adopted by other universities. Additionally, the procedure was presented to the international meeting at Budapest in 2021 and received a certificate. The program is currently used for education at TSU. Overall, this program brings positive facets for the improvement of agriculture and bioenergy in the US. It has contributed to advance knowledge and subsequent research on this important crop. Future activities will encompass greenhouse and field studies of new soybean lines and farm expositions.
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Gene Editing and Functional Genetics to Improve Legume Nitrogen Acquisition
Dr. Sonali Roy
Situation:
Nitrogen is the first nutrient to become scarce in soils, reducing agricultural productivity. The production of nitrogen fertilizers necessitates the use of environmentally hazardous fossil fuels. Nitrogen in agriculture must therefore be used with caution so that the benefits outweigh the negative effects of overuse. Exploiting the plethora of root associated microbes that help plants acquire N that is inaccessible to them is one method of making plants independent of nitrogen fertilizer: the best studied example being legumes and their beneficial partners, rhizobia.
Activity:
(1) Optimizing plant interactions with beneficial soil bacteria, which can help provide essential nitrogen and make plant growth completely fertilizer independent, is a critical strategy for addressing agriculture's nitrogen problem. This program investigates the molecular basis of the legume-rhizobia symbiosis using gene editing and functional genetics. (2) We focus on the role of peptide hormones controlling the legume-rhizobia interaction and in mediating responses to heterogeneous nitrogen availability in soil. Peptide hormones are understudied signals with the potential to make fundamental discoveries in the regulation of interactions with beneficial microbes, changes in root architecture, and nutrient uptake.
Impact:
We discovered naturally occurring peptides that, when added to legume roots, can increase nutrient uptake rates by 70-140%, as well as others that modify root architecture upon application. Future research will attempt to understand how roots recognize these signals and whether the addition of these peptides has epigenetic effects. A major focus of the lab is student training in plant biotechnology, gene editing and molecular biology.
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Germplasm Enhancement in Soybean Using Novel Molecular Tools and Techniques
Dr. Ali Taheri
Situation:
Genetic variation is a necessity for successful plant breeding. Lack of genetic diversity is considered the main bottleneck in soybean breeding programs. Genetic variation can be expanded by screening collections of soybean landraces from around the world. Induced mutation and genome editing are other techniques for increasing genetic diversity. Harnessing the beneficial traits of existing and newly created genetic diversity is the main purpose of this research.
Activities:
The first objective in this program is to develop a mutant soybean population and screen it for valuable traits such as reduced allergens and improved nutritional values. The second objective is to phenotype a diverse panel of soybean lines for root architecture and nodulation behavior and identify the lines with better root profiles and nitrogen fixation power. The third objective is to establish plant transformation protocols and their use for genome editing using CRISPR-Cas9 technology.
Impact:
New population developed in this lab is from a high yielding soybean line (JTN-5203) which is well adopted to Tennessee. Mutants generated through this method are considered non-GMOs, that are not required to go through the regulatory path as transgenic plants. It expands the market for the soybean grown in the US and ultimately benefits farmers and US economy. In this lab, we also look at the nitrogen fixation traits and root system architecture in soybean and identify cultivars that are capable of fixing more atmospheric nitrogen and withstanding harsher climatic conditions such as water deficiency or soil salinity.
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Climate-smart Practices and Tools for Enhancing Agricultural Productivity,
Profitability, and Sustainability
Dr. Resham Thapa
Situation:
In the southeast US, climate change is expected to shift hydrologic cycles such as altered rainfall patterns and increased frequency and severity of extreme weather events such as heat waves, droughts, and floods. Decoupled nutrient cycling, declining soil and water quality, and new pest management challenges further pose threats to the sustainability of our food production systems. Therefore, we must develop climate-smart agricultural systems that not only mitigate and adapt to changing climates but also provide other ecosystem services while increasing management flexibility to our farmers.
Activity:
This program conducts meta-analysis, lab and field experiments, and modeling to assess the effects of multiple climate-smart practices such as cover crops, conservation tillage, crop rotation, organic amendments, and precision nutrient management on climate change mitigation/adaptation, soil health, greenhouse gas emissions, nutrient cycling, and crop yield stability under current and future climates. Future research also aims to collect data to parameterize existing models and decision support tools to better serve farmers and agricultural professionals in Tennessee.
Impact:
Increased adoption of climate-smart practices will necessitate decision support tools that are site-specific in recommendations while national in scope. By investigating how soil, climate, and management impacts provisioning of ecosystem services from climate-smart practices, we will generate science-based recommendation systems and tools to enable real-time decision making and long-term planning by farmers and agricultural professionals. Our goal is to make agriculture productive, profitable, sustainable, and resilient under changing climates.
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Research and Applications in Biotechnology to Enhance Plant Productivity Against Worsening Environmental Conditions
Dr. Suping Zhou
Situation:
Plants produce the highest yield and best quality when provided with optimal environmental conditions. Abiotic stresses, like acidic soil associated with aluminum toxicity, drought, and abnormal hot or cold temperatures, are major problems threatening yields of agricultural crops. Our research aims to provide scientific information regarding the genes and proteins involved in the tolerance mechanisms that plants use against these stress factors. We also want to develop technology to produce tolerant lines that will be eventually integrated into plant production systems. In addition, our laboratory and field research activities help to train future scientists through various educational activities.
Activity:
We conduct research projects funded by NIFA, NSF, other federal agencies, Tennessee Department of Agriculture, and private companies. Working together with USDA/ARS scientists, we develop new technologies to identify the molecular mechanisms for stress tolerance. We are producing gene-edited plants and evaluating the function of the genes. Research projects are integrated with training of post-docs, MS and PhD students.
Impact:
The outcome of our research contributes to the mission of building a climate-resilient agricultural system.
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Speciality Crops
Entomology and Chemical Ecology
Dr. Karla Addesso
Situation:
Arthropod pests in Tennessee woody ornamental production reduce the quality and quantity of trees and shrubs reaching the wholesale and retail markets.
Activity:
Form collaborative networks with research/extension faculty and industry members working in ornamental production in order to identify and address these problems through active research and extension education of grower. Among the key pests of interest my lab has worked on include Japanese maple scale, ambrosia beetles, flatheaded borers, Japanese beetles, imported fire ants and spider mites. This work has formed the foundation of a collaborative effort to define best management practices for flatheaded borer control across North America in multiple commodities, including ornamental nursery, landscape, fruit and nut orchards.
Impact:
From my Japanese maple scale research, timed applications of growth regulators and annual management plans have been adopted by Tennessee growers, reducing the number of rejected shipments and culled trees. From my potato leafhopper research, two new foliar spray recommendations were identified. From my flatheaded borer research, knowledge has been gained on the longevity of insecticide products as well as natural methods for preventing borer attacks. We have also identified a production activity that induces borer attacks. The anticipated impacts of the next four years of borer research will be increased knowledge of effective management practices, increased adoption of optimized management tools and associated cost savings for growers.
Promoting Integrated Pest Management in Tennessee
Dr. Kaushalya Amarasekare
Situation:
Integrated pest management (IPM) of arthropod pests is a holistic approach to sustainable agriculture that focuses on managing pest problems through a combined effort of cultural, physical, biological, and chemical methods. It is the most critical strategy for managing pests in agricultural cropping systems. Yet, Tennessee growers, small farmers, and community and backyard gardeners are still behind in adopting and implementing IPM for crop protection.
Activity:
This program is focused on conducting applied research experiments and educating stakeholders on IPM through training and publications to promote IPM in the state. My applied research program is focused on finding sustainable pest management practices for small farmers, organic growers, and backyard and community gardeners. We conduct in-service training programs for Extension agents and IPM workshops for other stakeholders, including new farmers, on a state-wide basis in the East, Middle, and West Tennessee regions. My Extension publications are freely accessible through the TSU’s College of Agriculture website.
Impact:
The post evaluations conducted for training workshops on IPM revealed that 85 % or more of the participants had improved their knowledge of IPM. New farmer academy trainees and Extension agents request further training on IPM. Stakeholders are interested in exploring sustainable pest management techniques in their cropping systems.
Disease Management in Nursery Cropping Systems
Dr. Fulya Baysal-Gurel
Situation:
The Tennessee nursery industry is a major economic contributor and employer in rural areas. Nursery crop diseases caused by economically important and pervasive fungal, oomycete and bacterial pathogens threaten the profitability and sustainability of the nursery industry through complete plant lost, reduced marketability and restrictions on nursery trade from state quarantine.
Activity:
This program is developing new protocols for nursery crop disease management; providing diagnoses of biotic and abiotic problems and management recommendations to support sustainable nursery production.
Impact:
New fungicides, bactericides, biocontrol products were screened for their efficacy on different pathosystems. Our data led to new products being approved or fungicide label changes. Developed rotation programs specifically on rose downy mildew management has been adopted by the producers and this directly reduced the risk of fungicide resistance development. The first and only study for control of the plant parasitic algal leaf spot caused by Cephaleuros on woody ornamental crops was conducted by our team and this research results helped growers to successfully manage algal leaf spot on woody ornamentals and reduce the disease severity on their crops. Since quarantine implementation, my program plays critical role on diagnosis of boxwood blight disease and processes all TDA boxwood samples for boxwood blight confirmation and pathogen isolation. We evaluated the effect of fungicides, biofungicides, and host plant defense inducers for preventive and curative control of Phytophthora root rot and ambrosia beetle attacks in flood stressed nursery crops. The results help nursery producers successfully manage Phytophthora root rot and also reduce the risk of ambrosia beetle attacks during flood events.
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International, Alterative, and Niche Fruit and Vegetable Crops for Small Farm Producers
Dr. Arvazena Clardy
Situation:
Tennessee’s small producers are seeking to increase their incomes through alternative marketing and growing new, international and alternative crops. Bitter Melon, Bottle Gourd, and Tinda have documented health benefits and can be grown in Tennessee. These vegetables are sold in many international grocery stores, however, their shelf life is short, and the products often spoil before sale. International consumers use these vegetable and fruit crops in their daily diets and are always seeking fresh varieties for consumption. Since these alternative vegetables and fruits are nutritious, they could be marketed to health consumers, specialty restaurants, health food stores, juice bars and individual sales for home juicing and consumption.
Activity:
We are researching optimal growing methods for these products for small Tennessee producers and developing various marketing outlets (farmer market, direct sales, wholesale to restaurants, and CSA). Year-round production is a goal, because Bitter Melon assists in controlling A1C Level in diabetics, year-round consumption is needed for these patients and for those who traditionally eating these vegetables.
Impact:
We have several growers of Bitter Melon, which presently sell between $6.00 and $9.00 a pound, and one grower has established a market and steady customers who purchase from her over the past three years. We have been working with an internal medicine doctor who is interested in Bitter Melon for his diabetic patients who are not totally controlled with medicines. Recipes are being created, especially for those who have never consumed these delicious new vegetables and fruits.
Sensing and Robotic Technologies for Nursery Crop Production
Dr. Md Sultan Mahmud
Situation:
The nursery industry has been an important part of Tennessee for many years and accounts for a significant portion of agricultural production. Due to higher dependency on labor and inefficient conventional crop management, this industry has been slowing down recently in production. Current nursery management operations increase production costs. Alternative solutions such as mechanized or automatic management technologies are seriously needed to reduce labor needs and ensure efficient crop management.
Activity:
This program is developing a series of mechanized or automatic crop management technologies to alter the conventional labor-intensive and inefficient production operations for nursery crops. The ultimate goal of this program is: 1) to develop automatic technologies for crop planting, shape forming, weeding, and harvesting that will reduce labor requirements, 2) to innovate automatic crop disease management systems to apply agrochemical site-specifically that will optimize the chemical usage and reduce environmental contamination, and 3) to implement internet of things (IoT)-based irrigation water management technology that will increase water use efficiency.
Impact:
Labor is a problem not only for the Tennessee nursery industry but also nationwide. Nearly 80% of the nursery growers identified the labor issue as the most significant problem for their production. This research program will provide strategic sensing and robotic solutions to the current challenges faced by the growers of the nursery industry to minimize labor requirements and enhance profitability. Overall, this program will promote long-term economic and environmental sustainability for the nursery industry.
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Microbial-based IPM as a Tool for Sustainable Crop Production
Dr. Margaret Mmbaga
Situation:
Fungal pathogens cause huge crop losses and threaten crop production and food security worldwide. Current disease management strategies rely heavily on chemical pesticides that cause toxicity hazards to humans, nontarget organisms and contaminate the environment. Other options like cultural practices and disease resistance are not always available or adequate. Resistance break- down and pesticide resistance are additional problems. Biological control technology that uses beneficial microorganisms is a safe alternative tool for disease management. Although few biocontrol products are available commercially, more products are needed, and growers need more information on such products. The overall goal of the Phytopathology program is to develop biocontrol agents from selected bacteria that colonize internal plant tissue without causing harm to the plants. Such organisms have been shown to provide protection against plant diseases and promote plant growth.
Activity:
i) Evaluate of selected organisms individually and in mixtures and identify combinations that are effective as biocontrol agents. ii) Initiate mass production and stabilize the selected candidate bacteria for large-scale use in field environment and evaluate the quality of inoculum. iii) Evaluate a biological-based IPM as a tool for sustainable crop production. iv) Disseminate research results to growers and extension agents.
Impact:
Biological agents for disease control and plant growth promotion will provide alternative products for sustainable crop production. Dissemination of information to growers will provide important tools for organic farming and reduce usage of pesticides in conventional farming.
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Organic Agriculture Research, Extension, and Education Program
Dr. Dilip Nandwani
Situation:
In the US, the organic food industry reached $61 billion in 2021, but growth is much slower in most of the southern states. The slow adoption and growth of organic farming is mainly because it requires more specified production and management practices than conventional production systems due to the challenges of climate, nutrients, weeds, insect pests and disease management. The organic research and extension program develops strategies and technologies for fresh, safe, local, and nutritious crop production for urban, semi-urban and rural settings statewide.
Activity:
Several research trials conducted on various row covers in mini tunnels for pest and disease control in leafy greens; organic mulches for weed control in sweetpotato; humic substances in melons and sweet pepper; and vertical systems. Results disseminated through scientific conferences, growers’ meetings, training workshops, field days and fact sheets.
Impact:
1. Higher yield and no pest incidences recorded under row cover treatments compared to control (open) in leafy green vegetables. 2. Dry weight of weeds was fundamentally reduced by the various mulch treatments. 3. Vertical growing system demonstrated a viable alternative for vegetable production in controlled environment for urban settings. 4. Phytochemical profiles and antioxidant activities in melons were significantly influenced by the type of biostimulant applied. 5. Program impacted over 10,000 beneficiaries through 160 outreach events; 90% reported increase in knowledge in organic vegetable production practices, vertical farming, and certification process.
Invasive and Key Insect Pest Management in Nursery Cropping Systems
Dr. Jason Oliver
Situation: The Tennessee nursery industry is a major economic contributor and employer in rural areas. Invasive insect pests such as imported fire ant, Japanese beetle, granulate ambrosia beetle threaten the profitability and sustainability of the nursery industry through direct plant damage and restrictions on nursery commerce from various state and federal quarantines.
Activity: This program is developing new protocols for imported fire ant and Japanese beetle quarantines and for preventing wood borer trunk damage. The nursery industry is threatened by the loss of chlorpyrifos, which is the primary USDA approved insecticide for shipping nursery stock to fire ant quarantined areas. New treatment options are being developed with improved pre-harvest application, lower exposure risks and costs, and longer certification. Imported fire ant and Japanese beetle biological control agents have been released to reduce statewide populations of these pests.
Impacts: New treatments were developed for ambrosia beetles and flatheaded borers. The insecticide imidacloprid is now widely adopted by growers due to results from this program. A trap was developed that led to the USDA national emerald ash borer survey program. Our data led to new insecticides being approved as Japanese Beetle pre-harvest treatments, and chlorpyrifos rates were reduced eight times. For imported fire ant, new treatments were approved, and the chlorpyrifos root ball drench protocol (used by most growers) was reduced from six drenches to two drenches, producing a significant reduction in worker exposure, time, and cost and saving millions in application costs. Other invasive insects are also being examined and more producer savings are expected with new protocols under development.
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Crop and Site-Specific Nutrient Management for Sustainable Crop Production
Dr. Dharma Pitchay
Situation: The current fertilizer recommendations for crops are general rather than crop- or site-specific. As a result, it is less effective in increasing yields and quality of produce. Furthermore, this leads to runoff, which affects both surface and groundwater. An effective tailor-made crop-specific nutrient management is a critical factor for increasing productivity and sustainability.
Activity: The research, teaching, and extension activities include investigating crop-specific nutrient management based on 4R Nutrient Stewardship: applying the right nutrient source, at the right rate, right time, and in the right place, and documenting nutrient deficiency symptoms of food crops. The identification of nutrient deficiencies provides farmers with a valuable diagnostic tool. Once the underlying deficiency is known, strategies can be developed to help avoid losses in yield or crop quality. Electronic publications and posters on plant nutrition diagnostics of food crops including potato, broccoli, raspberry, etc. are available for growers.
Impact: The practice of new and improved techniques of crop and site-specific fertility management based on 4Rs Nutrient Stewardship (Source, Rate, Method, and Timing), and diagnosing nutrient deficiencies based on visual diagnostic tool has saved inputs, especially fertilizers, which in turn increased yield, farm revenue, soil health, and improved the environment.
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Nursery Production and Sustainability - Improving Profitability and Reducing Inputs in Nursery Crop Production
Dr. Anthony Witcher
Situation: Nursery crop producers may encounter a wide range of biotic and abiotic factors that affect crop growth and quality. These factors include pests (insects, pathogens, weeds, etc.), mineral nutrition, and environmental conditions (excessive rain, drought, wind, temperature extremes, etc.). Best management practices for nursery crop production (methods for minimizing the environmental impact of producing plants) are being more widely implemented throughout the industry. Nevertheless, balancing the environmental and financial impacts of crop production is an ongoing challenge for nursery crop producers.
Activity: The focus of the nursery production and sustainability program is to address major issues in sustainable nursery crop production with an emphasis on weed management, cover crops, and alternative soil/substrate amendments. Current projects include evaluating alternative weed control methods for nursery crop propagation and production, evaluating cover crop establishment and management in field-grown nursery crops, utilizing unmanned aerial systems (UAS) for detection of stressed plants, managing herbicide resistant weeds in nursery crops, evaluating alternative substrate amendments for improved crop quality and reduced pesticide use, and screening new herbicides for crop safety and efficacy.
Impact: This research will lead to new practices that result in the reduction of inputs (pesticides, fertilizer, water, labor, etc.) in nursery production systems, thus enhancing the sustainability of the industry, improving our environment, reducing production costs for growers, improving crop quality, and broadening the market for Tennessee green industry products.
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