Duration: 10/01/2026 to 09/30/2031

Administrative Advisor(s):

NIFA Reps:

Non-Technical Summary

High tunnels systems are low-tech greenhouse-like structures that increase the length of the growing season, yield, crop quality, and nutrient uptake efficiency, and provide some climactic control compared to field production. Myriad research and extension activities related to high tunnel production are taking place across the U.S. However, due to the broad geographic dispersal of high tunnel research and extension personnel, a forum to promote coordination and collaboration is needed to support multi-state, multi-institutional, and cross-disciplinary approaches to solve common problems. Thus, this multistate research project seeks to Advance High Tunnel Specialty Crop Production. Project members aim to work in a coordinated manner to: 1) Assess high tunnel systems in the U.S. to determine rates of adoption, technology use, and impact on U.S. food production, 2) Identify and study effective crop management strategies, including pest and disease management, in high tunnel systems, 3) Identify cost-effective uses of engineering, technology, and infrastructure to improve environmental control and crop health within high tunnels, and 4) Investigate and develop strategies for sustainable soil health management in high tunnel systems.

Statement of Issues and Justification

High tunnels are portable, greenhouse-like structures with a single or double layer of plastic, with or without supplemental heat, power, or mechanical ventilation, with crops usually grown in-ground (Wells and Loy, 1993). High tunnels increase the length of the growing season, yield, fruit quality, and nutrient uptake efficiency, and provide some climactic control compared to field production (Reeve and Drost, 2012) at lower expense than heated greenhouses. High tunnel production became widespread in the 1990s and has increased dramatically in recent years as federal conservation initiatives through the U.S. Department of Agriculture Natural Resources Conservation Service (NRCS) incentivized installation of new tunnels beginning in 2009. For example, between 2017-2020, over 2000 contracts for high tunnels were awarded annually through the NRCS high tunnel initiative (Donovan et al., 2023). High tunnels funded by NRCS have specific requirements that set them apart from other protected culture practices (e.g., low tunnels, some caterpillar tunnels, and soilless hydroponic systems): 1) crops must be grown in natural soil although up to 12 inch (depth) raised beds are allowed, 2) the high tunnel must stand 6 ft tall or higher, 3) the maximum size allowed is 2,160 ft², and 4) tunnels must be built from pre-approved kits (no DIY designs allowed). Heating/cooling units or electricity is not covered by NRCS funding, but growers can install these tools on their own. This style of high tunnel dominates protected culture in the U.S., so this project will focus on developing innovative pest, soil, and climate control tools tailored to these systems.

High tunnels are typically used to lengthen the growing season for warm-season crops such as tomato, eggplant, pepper, and cucurbits (Carey et al., 2009; Fitzgerald and Hutton, 2012; Knewtson et al., 2010; Lamont, 2009; O’Connell et al., 2012; Gong et al., 2022). High tunnels also permit growers in colder climates to grow crops during times when it would otherwise not be possible, and to grow perennial crops that could not be grown in the region otherwise, thereby increasing market opportunities (Fitzgerald and Hutton 2012, Sideman unpublished data). Several studies have shown that high tunnels confer yield and quality benefits (Frey et al., 2020, O’Connell et al., 2012, and many others). In addition to increasing economic stability and earnings, farmers report better yields, easier management of some pests and diseases, and an increased quality of life when using high tunnels on their farms (Bruce et al. 2019a, 2019b). 

Several regional surveys of high tunnel producers and extension professionals have identified benefits and advantages of using high tunnels, as well as challenges that define research and educational needs (Fitzgerald and Hutton 2012, Foust-Meyer and O-Rourke 2015, Bruce et al. 2019b, Sideman et al. unpublished; Nian et al. 2025). The protected environment created by high tunnels not only alters crop growth as compared with open field conditions, but also modifies soil moisture dynamics, nutrient mineralization and leaching, the environmental suitability for pest and disease development, and behavior of pathogens and both pest and non-pest organisms including natural enemies and pollinators. With their small area and high land value, high tunnel soils are often managed intensively, with heavy (and possibly excessive) inputs of fertilizer and other amendments. The many differences between high tunnel and open field production necessitate the use of crop varieties, entire production systems, and pest and disease management strategies unique to high tunnels. Management challenges also exist, such as increased labor and time requirements and increased complexity of high tunnel production (Bruce et al., 2019b). Thus, several research and outreach priorities and challenges are specific to high tunnel systems. While there are certainly regional differences, many of the high-priority challenges related to high tunnel production are common to producers across a wide geographic area.

According to Lamont (2009), the U.S. had approximately 5,000 ha of high tunnels and greenhouses combined at that time. In 2010, the USDA-NRCS began to incentivize new high tunnel installations; 9,489 high tunnels (representing at least 176 ha) were added throughout the U.S. between Jan 2010 and Dec 2013 alone (Foust-Meyer and O-Rourke 2015). However, despite increasing prevalence of high tunnels, we don’t have accurate data about how many high tunnels are in operation throughout the U.S. or about their economic importance to small- and mid-sized farms. The U.S. Department of Agriculture’s National Agricultural Statistics Service (NASS) groups all protected cultivation (high-tech greenhouses and low-tech high tunnels) together. Estimates obtained through an informal survey conducted by Carey et al (2009) were highly variable, and high tunnel definitions were not consistent.

Myriad research and extension activities related to high tunnel production are taking place across the U.S. However, due to the broad geographic dispersal of high tunnel research and extension personnel, a forum to promote coordination and collaboration is needed to support multi-state, multi-institutional, and cross-disciplinary approaches to solve common problems. 

In 2020, the multistate coordinating committee NECC-2103 High tunnel specialty crop production, was formed. The purpose of this coordinating committee was to facilitate collaboration across states to: 1) characterize the high tunnel ‘landscape’, e.g., to quantify high tunnel acreage and production systems, 2) research pests and diseases unique to high tunnel production systems, 3) determine adaptability of new cultivars to high tunnel production systems, 4) research strategies to optimize soil, nutrient, water, temperature, and crop management in high tunnels, and 5) share research plans to avoid duplication and inefficient use of resources, and to foster multi-institutional and cross-disciplinary research.

Since inception, this committee has met regularly and has built its membership steadily; NECC 2103 currently has 28 members from 16 states. Over the last year, the coordinating committee officers met and discussed with membership whether to continue as a coordinating committee, or to instead propose a multi-state research proposal. We decided to move forward with a proposal to create a multistate research project focused on Advancing high tunnel specialty crop production. Since the inception of NECC 2103, the number of faculty and extension educators in CEA has increased across the U.S., further justifying the need for this multistate project.

Related, Current and Previous Work

While representing a unique focus, the activities of this multistate project complement other projects: NE1835-Resource Optimization in Controlled Environment Agriculture (which is primarily focused on higher-tech greenhouses rather than lower-tech high tunnels), SERA45-Crop Diversification Opportunities to Enhance the Viability of Small Farms, which includes protected agriculture as one strategy for crop diversification, and NE2401-Urban Agriculture: Innovation, Stewardship, and Local Engagement. We envision possible linkages and information sharing between these groups.

Below, we present a short description of the situation, previous work, and needs relating to each of our four objectives.

Objective 1: Assessment of high tunnels in the U.S. to determine rates of adoption, technology use, and impact on U.S. food production

A challenge with conducting research and outreach related to HT systems is that we do not have an accurate assessment of the impact, in acreage or production value, of crops grown in these low-tech and cost-effective protected production systems. Grower surveys and other qualitative / quantitative approaches have been conducted by separate researchers in different geographic areas to try to better understand the HT landscape. For example, tomatoes were found to be the most commonly grown crop in HT systems, followed by cucumber and leafy greens, and to a lesser extent, cut flowers, eggplants, peppers, and a variety of other crops in past surveys (Fitzgerald and Hutton 2012, Carey et al. 2009, Lamont 2009). However, these surveys are quite dated and limited in describing the current role HTs have for specialty crop production at larger regional or national level. Current data relies on NRCS reporting and USDA census, the latter of which lumps high tunnel production with high tech greenhouses as the category “Crops Grown Under Glass or Other Protection”. It has been 16 years since the NRCS cost-share initiative, so there is clearly a need to survey HT production to determine impact and the importance of HTs on local food systems. 

In addition, substantial advancements have been made in agricultural technology and the extent to which these innovations have been adopted by HT growers is unknown. There is a range of technologies observed in HTs including the use of movable HT technologies, supplemental heating, cooling or lighting, different types and the degree of automation of ventilation (roof vents, roll-up or roll-down sides, end-wall vents, etc.) and irrigation systems, environmental monitoring systems, the use of specialty films, energy curtains, shade cloth, insect exclusion netting, supplementary row covers, and spraying technology. We also lack concrete data on the costs and benefits of these practices, which limits our ability to help producers with data-driven decision making to guide investment decisions. 

This objective will fill critical knowledge gaps in current rates of HT adoption and use of technology in HTs, at both a regional and national level. This effort will improve our understanding of HTs in our region(s) and will help ensure that research and outreach investments are made wisely and that they are most impactful to stakeholders. 

Objective 2: Improvement and optimization of Crop management strategies, including pest and disease management, in HT systems. 

Pest and disease management: Pest and disease complexes in HTs frequently differ from those seen in outdoor conditions, due to many factors including altered light, temperature, precipitation, humidity, length of growing season, and myriad other factors (Couture et al. 2023; Cramer et al. 2019). For example, pests can have an expanded overwinter survival range with the protection offered by HTs, and the efficacy of biological control organisms can be impacted by these environmental variables (Ingwell et al. 2018). Pest pressure in HTs often exceeds the open field because pests can establish earlier and reach thresholds faster. There is a need to better understand the biology and management of pests and diseases that are prevalent in HT systems.  Current pest/disease management tools available to HT growers are restricted to those tailored to the open field or greenhouse systems. However, HT environments are unique and may not always resemble either. Many U.S. states interpret HTs as traditional greenhouses, therefore only greenhouse-labeled pesticides can be applied in HTs. There are many open-field pests/diseases present in HTs that are not included on these labels. Preventative tactics, FIFRA Section 25(b) minimum risk pesticide products, and biocontrol are sometimes the only options for HT growers. How to use these products in HTs is a large knowledge gap, as release/spray rates are likely to differ compared open-field and greenhouse systems. This objective will fill these important knowledge gaps across regions and provide more tailored guidelines for pest/disease management for HT production.

Managing abiotic disorders: The HT environment presents unique challenges and opportunities for each crop. While HTs commonly increase yield potential, they can also alter (and sometimes increase) the prevalence of disorders that reduce marketability, such as yellow shoulder in tomato (Pandey et al., 2024). Crops grown in HTs are often managed very differently than the same crop grown outdoors, to capitalize on the extended growing season and improved environmental control. Crops grown in HTs are also managed differently from the same crops grown in greenhouse systems, where even more environmental control is possible, and systems allow for precision nutrition, light, and water management. Slight differences in crop management (e.g. spacing, pruning, fruit thinning, harvest strategies, etc.) can result in large differences in crop quality and productivity (Torres-Quezada and Gandini-Taveras 2023, Reid et al. 2023, Gude et al. 2022, Aurora et al. 2024, Murariu et al. 2021). There is a need to identify cultivars adapted to HT production, as well as those with resistance or tolerance to HT pests and disease complexes.  

Objective 3: Cost-effective uses of engineering, technology, and infrastructure to reduce labor requirements and improve environmental control and crop health within HT. 

HT systems are commonly used on highly diversified small- to medium-scale farms, in part because they represent a relatively small investment in comparison with high-tech greenhouses. HTs offer an intermediate level of environmental control, compared with uncontrolled open-field and highly controlled greenhouses. HTs can be equipped with a wide range of technologies and infrastructure that permit ever increasing environmental control and mechanization, with varying degrees of investment required. The semi-controlled environment provided by HT systems has been shown to increase yield and quality of a wide array of specialty crops (Carey et al. 2009). 

In high-tech greenhouses, a suite of technologies and infrastructure investments are used to maximize control of the crop environment and to increase labor efficiency. Technological advancements are occurring rapidly, and the cost of implementing such technologies is decreasing rapidly. While the degree to which specific innovations have been adopted in HTs has not been quantified formally, we do know that some innovations have been adopted more widely (supplemental heating, the use of supplemental row covers for winter protection) than others (sensor-driven irrigation, mechanized ventilation). There are also newer approaches being adapted for use in HT conditions. For example, environmental modification strategies such as evaporative cooling and fogging systems have been shown to mitigate heat stress, reduce physiological disorders, and increase yields in HT systems (Sharaf-Eldin et al., 2023). With rapid innovation in greenhouse technologies, continuous evaluation of the suitability of new technology for use in HT systems, and adaptation to use by diversified and small-scale producers, is needed.  

Objective 4: Sustainable soil health management in HT systems. 

One factor that distinguishes HT from greenhouse systems is that crops are typically grown in-ground, in heavily amended native soils. It is well established that HT soil-nutrient-water dynamics differ considerably from those in open fields in the same soil type (recently reviewed by Pierre et al., 2024; Ali et al. 2022). High fertilization rates are often used in HT systems to ensure high yields in this high-value space, and the lack of overhead rainfall creates an arid, desert-like environment in otherwise humid climates. Buildup of excess phosphorus (P), resulting from application of organic amendments to meet nitrogen (N) needs, is common. Cover cropping, especially with legume cover crops to provide N without P, could be a possible solution to some of these issues (Perkus et al., 2022), but several barriers limit widespread adoption of cover cropping in HTs. Cover cropping is especially difficult to implement in HTs that are used for year-round production, as there is a limited window to grow and terminate a cover crop before the next season's rotation. Ultimately, HT producers frequently grow the same high-value crop year after year and use crop rotation and cover cropping less frequently than they would in outdoor field soils.

Together, these factors lead to some consistent challenges in soil management in HT systems including high soluble salts and the buildup of crop-specific soilborne pests and pathogens, including weeds. The limited crop rotations and the warmer temperatures have also led to the development of several emerging soilborne pest and pathogen issues within HT (Hamal et al., 2025), which necessitate the development of new sustainable soil health management strategies applicable in HT (Frey et al., 2020; Rosskopf and Di Gioia, 2023; Di Gioia et al., 2024). Considerable research and extension effort has been spent evaluating the suitability of different soil testing approaches for HT conditions and developing guidelines for sustainable soil management in HTs. Pierre et al. (2024) recently summarized knowledge and knowledge gaps in the role of soil health in high tunnels systems, and concluded that there is a need to better understand the soil-nutrient-water dynamics within HT soils, and to develop clear research-based recommendations for practices like cover cropping, anaerobic soil disinfestation (ASD), steaming, and soil testing and fertilization strategies.

Objectives

1. Assess high tunnels in the U.S. to determine rates of adoption, technology use, and impact on U.S. food production.
   
2. Identify and study effective crop management strategies, including pest and disease management, in HT systems.
   
3. Identify cost-effective uses of engineering, technology, and infrastructure to improve environmental control and crop health within HT.
   
4. Investigate and develop strategies for sustainable soil health management in HT systems.
   

Methods

Objective 1. Assess high tunnels in the U.S. to determine rates of adoption, technology use, and impact on U.S. food production

We aim to work collectively to explore how growers are using HT in general, and specific technologies within HT systems, to better understand the costs and benefits of HT growing practices. We aim to generate concrete data about the returns on investment for particular crops and technologies to help develop effective outreach products, including guidance and decision-support tools for HT users. Addressing these information gaps in a concerted and coordinated way, at both a regional and national level, will be useful to help guide future research and outreach investments to maximize impact. 

This objective will largely include extension efforts to survey HT production across participating regions in the U.S. Surveys will be written by project collaborators and distributed to extension networks in their region. Surveys will inquire about the following information:

• The approximate number and size of HTs within the region covered by each extension specialist. This information will supplement current NRCS and USDA data to track current use and rates of HT adoption.
• Dominant crops grown in HTs and key production challenges for different crops noted by growers. This information will track changes in HT cropping systems and identify priority areas for research/extension education. It will also help determine region-specific needs.
• Current use of technology in HT. There is a diversity of technological use by HT growers, but no current effort to describe these trends. This question will determine which tools (e.g., supplemental heating/cooling/climate automation) are most popular among HT growers. Objective 3 will provide more empirical data supporting cost-efficacy of these tools.

The survey instrument developed will be available in diverse formats and platforms to facilitate data collection. Our goal will be to cover all counties within participating states. Regular data will be available to the project team and extension educators participating in this survey to ensure buy-in and knowledge reciprocity. Results of the survey will be discussed during annual project meetings and published shortly thereafter as an extension article. Any revisions to the survey will also be discussed during the yearly meeting. Growers will be engaged in this objective through current extension programming.

Objective 2. Identify and study effective crop management strategies, including pest and disease management, in HT systems. 

We will work in a coordinated manner to evaluate the adaptability of new crops in HT systems, and to explore cultural practices and crop management strategies that optimize productivity and crop quality for crops grown in HT. We also aim to conduct studies that enhance our understanding of how the HT environment impacts pests, pathogens, and biocontrol organisms with the ultimate goal of improving pest management and building plant resilience in HT crop production.   

Studies to be undertaken include fundamental, on-farm, or applied research or outreach projects that:

1. Measure HT climates across regions. This effort will be necessary to determine environmental drivers for abiotic/biotic crop disorders. This effort will occur across participating states within research or grower HTs. Environmental loggers (temperature, humidity, light intensity) will be deployed at participating sites. Results from this sub-objective will be published in at least one peer-reviewed journal article and an extension newsletter.
2. Evaluate and compare varieties of high-value crops in HT. Tomatoes, cucumbers, and leafy greens dominate HT production, but little is known of the most popular and productive cultivars grown. Cultivars will be assessed at research or farm locations for pest / disease prevalence and crop performance. Fundamental research will identify genes and traits for cultivars underpinning these results and traditional/modern tools in plant breeding will be applied toward developing new cultivars with high performance in HT systems. The results of this sub-objective will be published in at least one peer-reviewed journal article and an extension newsletter per crop evaluated (tomato, cucumbers, leafy greens).  
3. Evaluate the performance of new crops for HT production. HT crop diversification is needed to reduce risk of pest/disease buildup in HTs. Rotation options for tomatoes in particular will be evaluated in applied research studies. Strawberries, ginger, herbs, beans, cut flowers, are examples of high-value, non-solanaceous crops that could be evaluated for rotation with tomatoes. The results of this sub-objective will be published in at least one peer-reviewed journal article and extension newsletters.  
4. Explore different crop management strategies, such as pruning, plant density, and timing of planting. Crop management varies considerably among growers, with many planting crops at a higher density in HTs to maximize space use. However, HTs restrict air flow, and dense plant canopies increase risk of disease. This objective will determine ideal plant spacing and pruning for common HT crops. Plant timing will also be evaluated, as some crops are planted later to avoid unpredictable spring weather or risk of pest/disease. Cucumbers, for example, are highly vulnerable to cucumber beetle damage and bacterial wilt (vectored by cucumber beetles) early in the spring that may be avoided by planting later. This sub-objective will determine optimal crop management strategies that are regionally adapted for common crops grown in HTs and will result in at least two peer-reviewed journal publications and extension newsletters for each crop evaluated (tomatoes and cucumbers are high-priority).
5. Evaluate the behavior and efficacy of pests and biological control organisms. Current biocontrol recommendations (e.g., biopesticide sprays and augmentative predators/parasitoids) are based on open-field or greenhouse production systems. This sub-objective will provide foundational data on the biology and behavior of common pests / diseases under HT environments to determine key risk factors. Common pests include aphids, thrips, spider mites, and whiteflies. Diseases include leaf mold, powdery mildew, and botrytis. However, other pests/diseases could be included in this sub-objective based on regional needs. Efficacy of current management tools under HT conditions will also be evaluated to potentially identify synergies or mismatches between pest/disease targets and intervention strategies within HT environments. A priority on biopesticides, augmentative biocontrols, and other 25(b) exempt / minimal-risk products will be made as these tools are available to all HT growers including those farming across the conventional – organic production spectrum. This sub-objective will result in at least six peer-reviewed journal publications and extension articles (split by common diseases / pests).

 

Objective 3. Identify cost-effective engineering, technology, and infrastructure to improve environmental control and crop health within HT

We aim to work cooperatively to bring innovations in design, mechanization, and engineering to HT production systems to improve environmental control and crop health, and to reduce labor requirements. Our approach will include evaluating and potentially adapting approaches being used in high-tech greenhouse systems for suitability in HT systems. This objective will use new tools, sensors, and technologies to measure and monitor airflow and temperature dynamics in HTs as a response to “active” and “passive” environmental controls.

Examples of studies to be undertaken include fundamental, on-farm, or applied research or outreach projects that:

1. Study “active” climate control tools . Most traditional greenhouses use “active” climate control to optimize crop productivity with electricity, fuel, and labor inputs. Active climate control tools include supplemental heating, cooling, and light fixtures. Simplified versions of these tools are available to HT growers, but many don’t use them or do so sparingly because they are expensive to run (especially supplemental heating). Overall, there is a significant knowledge gap in climate control tools in HTs, their direct benefits to crops, and how they can be optimized. This sub-objective will collect data from research and grower farms where these climate control tools across the spectrum are used and link their use to crop productivity and health performance. This will result in a minimum of two peer-reviewed manuscripts.
2. Study the use of “passive” management control tools, including row covers, shade cloth, exclusion netting, or other infrastructure to improve crop quality and protection. Most HTs rely on passive climate control tools (ventilation through open side walls) or simple infrastructure improvements (installing row covers for winter or exclusion netting to keep pests away) because they do not have access to electricity. The project team has evaluated a few of these tools (row cover and exclusion netting efficacy), but many have not been evaluated or compared across regions. Colored netting, for example, has not been evaluated for HTs but has shown to provide “optical” interference for dispersing pests in other production systems. This objective will focus on identifying passive climate and crop control tools that are accessible to all HT growers. This will result in a minimum of two peer-reviewed manuscripts.
3. Evaluate tunnel design and compatibility with growing regions. High tunnels come in several styles (gothic, Quonset) and different dimensions that are known to be more compatible with growing regions. This sub-objective will measure climates within these styles across farms to determine how well they regulate temperature and humidity conditions. Additional options, including movable tunnels, will also be considered for growing regions. This sub-objective will result in at least one extension article on choosing a high tunnel structure. 
4. Create decision support tools focused on economic returns to help producers decide whether specific practices or technologies are cost effective. This research sub-objective will evaluate active and passive strategies assessed above to balance input costs with benefits. This sub-objective will merge results from 3A and 3B into an extension guideline on climate control tools in HTs.

Objective 4. Investigate and develop strategies for sustainable soil health management in HT systems

We aim to work collectively to identify and define sustainable soil health management approaches for HT systems. Specifically, we aim to study the effects of practices like cover cropping, anaerobic soil disinfestation (ASD), and steaming in HT soils, and to better understand the barriers to adopting specific practices that could improve HT soil management taking into consideration site-specific environmental and soil conditions. We also seek to build an improved understanding of soil-nutrient-water dynamics, and to develop and refine evidence-based recommendations for soil testing and fertilization in HT.  

Examples of studies to be undertaken include fundamental, on-farm, or applied research or outreach projects that:

1. Identify nutrient testing methods and key indicators for soil health to assist decision-making regarding soil management strategies. Soil type and quality can be highly variable across farms, and it is critical to determine best practices for soil management. This sub-objective will evaluate best practices for rapid soil testing to guide decision making regarding soil amendments and management. The second effort will be to identify key indicators for soil health that can be monitored over time to improve management practices. This sub-objective will result in two peer-reviewed manuscripts and two extension articles to guide growers on soil testing and recognizing important parameters.
2. Study the use of cover crops as green manures and rotational crops in HT. This sub-objective will compare cover crops that are compatible with crop rotation in high tunnels. Timing of planting and termination practices will also be evaluated and followed up by soil testing to determine impact. This study will occur over multiple years to determine how soil structure / quality changes in long-term soil management and to explore the linkage between soil management practices and cash crop productivity. This sub-objective will result in a peer-reviewed manuscript and at least two extension articles on cover cropping in HTs.
3. Determine optimum fertility rates for HT-grown crops. This objective will track nutrient buildup in the soil following a continuum of fertilizer inputs recommended for HT-specific crops. Fertilizer inputs will also be evaluated based on pre-existing soil conditions. For example, fertilizers with no or low P will be evaluated in HTs where tomatoes have been consistently grown and have high P buildup. Yield and crop nutrition will be measured as responses to determine optimal rates of fertilizer. This sub-objective will result in a peer-reviewed manuscript and an extension article on fertigation programs in HTs for key crops (tomatoes, cucumbers, leafy greens).
4. Evaluate soil steaming, solarization, biofumigation, or anaerobic soil disinfestation (ASD) to manage soilborne pests and weeds. This sub-objective will span several objectives to determine how to manage soil that have soilborne pest, disease and weed emergence. Special attention will be paid to determine tradeoffs with these practices and the abundance of beneficial soil micro and macro diversity. This sub-objective will result in a peer-reviewed manuscript and an extension article for each soil management technique in HTs (3 articles).

 

Measurement of Progress and Results

Outputs

• Extension resources for holistic crop production in HTs Comments: We plan to write a minimum of 25 extension articles on this project and a cohesive guideline summarizing findings across objectives for high-priority crops (namely tomato and leafy greens). Team members from Purdue recently published a high-impact guide for cucumber production in HTs that we will use as a reference for other HT crops. Guidelines will be developed during the final year of the project. Results from individual objectives will also be published as they are achieved as individual articles, PowerPoint presentations, or other downloadable forms to make information sharable.
• Scientific contributions to the field Comments: The target research publication output is 22 peer-reviewed articles spanning each of our objectives over this 4-year study. The multistate team will also present research findings at scientific conferences.
• Project communication Comments: The multistate team includes researchers, educators, and Extension specialists, and we will collaborate with other Extension colleagues to share research findings and exchange information with stakeholders. This will largely occur during our annual meeting that will be held in tandem with popular Extension conferences. In addition, findings from this project will be integrated into undergraduate and graduate courses by team members who are actively involved in teaching at their institutions.
• Training and Mentorship Comments: The multistate team will train early-career professionals (including undergraduate and graduate students, postdocs, and technicians) in quantitative and qualitative research methodologies, scientific writing, and presentation skills to support their career goals. In-service training opportunities and workshops will be also offered to Extension educators working on HTs.

Outcomes or Projected Impacts

• Fill critical foundational knowledge gaps This project will contribute to discover biophysical and socio-economic dimensions of HTs that span diverse regions and production systems. This knowledge is critical to provide as HT adoption expands rapidly in the U.S.
• Knowledge exchange Members of this multistate project group will cover a range of specialized disciplines, including plant physiology, plant pathology, entomology, nematology, ecology, horticulture, soil science, organic farming, agricultural engineering, economics, sociology, etc. and will represent a broad geographical distribution. Exchange of information and ideas between group members will lead to collaborative, transdisciplinary projects, robust publications, and new and innovative specialized information. Through annual meetings, members will share information about existing projects and activities.
• An established network for rapid response to emerging HT issues By formalizing the group's goals and collaboration, we will build a stronger community doing research and outreach in HT cropping systems that will achieve longer-run objectives. This project is based on current HT issues, but our network will be used to share immediate and emerging concerns in HT production. The team will have a platform to communicate issues and lend their expertise to provide an informed and rapid response to collaborators.
• Opportunities to collaborate on competitive grants A massive strength of this team is our multidisciplinary and focus on improving HT production systems. Each year we will discuss grant ideas, priorities, and opportunities for collaboration. The multistate team will submit collaborative grant applications to external funding agencies and organizations.
• Strengthened relationships with grower stakeholders Each of our objectives span foundational to applied research and can include on-farm research. In some cases, as in Objective 1, coordination with growers will be necessary to fill important knowledge gaps regarding HT use and importance to local food systems.
• Improved confidence regarding decision making in HTs Achieving objectives of this project will provide evidence-based recommendations on HT production targeting key sectors of this holistic production system. This will allow growers to make confident choices that can achieve long-term benefits.

Milestones

(2026):Organize first group meeting (ideally in-person but, if needed, virtual). Elect group leadership. Summarize preliminary data for each objective and coordinate research efforts. Plan procedures for Objectives 1 and 2A that require regional or national efforts. Determine the timeline for Objectives 2-4 that will require a minimum of 2 years of evaluation. Build a communication infrastructure, including shared folders or a listserv that members can use to share information.

(2027):Organize annual group meeting. Elect new leadership team. Summarize progress towards outcomes, listing outputs produced. Distribute Year 1 of extension surveys through extension networks. Revisit timeline to achieve sub-objectives within Objectives 2-4.

(2028):Organize annual group meeting. Elect new leadership team. Summarize progress towards outcomes, listing outputs produced. Continue or revise surveys for Objective 1 and compile responses. Revisit timeline to achieve sub-objectives within Objectives 2-4.

(2029):Organize annual group meeting. Elect new leadership team. Summarize progress towards outcomes, listing outputs produced. Continue or revise surveys for Objective 1 and compile responses. Revisit timeline to achieve sub-objectives within Objectives 2-4.

(2030):Organize annual group meeting. Elect new leadership team. Finalize plans for project delivery, namely writing and publishing comprehensive 1st edition guidelines for HT crop production (individual guidelines for each crop). Finalize list of project outputs. Develop a plan for renewing the multistate research project that leverages the progress made over the project term. Submit the renewal.

Projected Participation

View Participation Form/Appendix E: Participation

Outreach Plan

Many of the participants are actively involved in both research and extension activities. Their research results and production recommendations will be disseminated through their state cooperative extension service. 

Additionally, information will be made available by members through many regional and state growers’ meetings such as the Great Lakes Fruit and Vegetable Exposition, the Mid Atlantic Fruit and Vegetable Conference, the New England Fruit and Vegetable Conference, the Empire State Expo, and the Southeast Regional Fruit & Vegetable Conference. In these meetings and other venues, our members will provide insight and recommendations for research priorities through presentations, field days and workshops, in-service trainings, newsletters, email, and websites on changes in legislation, upcoming issues, management of production, irrigation, fertility, insects, diseases, and variety choice in high tunnels.

Organization/Governance

The recommended Standard Governance for multistate activities includes the election of a Chair, a Chair-elect, and a Secretary. A new Secretary is selected at the end of the annual meeting at which point the current Secretary becomes Chair-Elect, and Chair-Elect becomes Chair for the next 12 months. The Committee Chair and Chair-Elect are responsible for organizing the annual meeting and planning the agenda, and The Secretary records the minutes at the meeting following their election.

Literature Cited

Ali Q, Abbas A, Khan MTI, Bagadeem S, Alotaibi BA, Tariq M, Traore A. 2022. Sustainable Agriculture through Reduced Emission and Energy Efficiency: Estimation of Input–Output Energy and GHG Emission under Tunnel Cultivation of Tomato. Agronomy. 12(8):1730. https://doi.org/10.3390/agronomy12081730.

Aurora CS, Alexandru Florin P, Adnan A, Elena D, Elena Maria D. 2024. High Tunnel Cultivation: Evaluating the Growth and Productivity of Different Tomato Varieties. IJAMRS. 4(4):1276–1284. https://doi.org/10.62225/2583049X.2024.4.4.3177. 

Blunk, A. 2022. Optimizing nitrogen management for grafted and non-grafted fresh-market tomatoes grown in high tunnels in Pennsylvania. M.S. Thesis, Pennsylvania State University. https://etda.libraries.psu.edu/files/final_submissions/26834 

Bruce AB, Farmer JR, Maynard ET, Valliant JCD. 2019a. Using high tunnels to extend the growing season and improve crop quality and yield: assessing outcomes for organic and conventional growers in the U.S. Midwest. International Journal of Agricultural Management. 8(2): 45-55.

Bruce AB, Maynard ET, and Farmer JR. 2019b. Farmers’ perspectives on challenges and opportunities associated with using high tunnels for specialty crops. HortTechnology 29(3):290-299.

Carey EE,  L Jett, WJ Lamont, TT Nennich, MD Orzolek and KA Williams. 2009. Horticultural Crop Production in High Tunnels in the U.S.: A Snapshot. HortTechnology 19:37-43.

Couture A, Gaudreau L, Van Sterthem A, Gosselin A, Dubé Y, Nguyen TTA, Brégard A, Doras M. 2025. How can high tunnel coverings and an insect-proof barrier improve productivity and pest management in berry crops? Acta Horticultura 1428 (101-108). https://doi.org/10.17660/ActaHortic.2025.1428.13

Cramer ME, Demchak K, Marini R, Leskey T. UV-blocking high-tunnel plastics reduce japanese beetle (Popillia japonica) in red raspberry. HortScience 54(5):903-909. https://doi.org/10.21273/HORTSCI13820-18.

Di Gioia, F., Balaguer, R., Pierre, F., Morrison, B., Ono-Raphel, J., Passerini, L., Vecchia, L., Demchak, K., Roman, C., Schmidt, C., Gugino, B., Elkner, T., Hong, J.C., Dini-Andreote, F. and Rosskopf, E. (2024). Optimizing anaerobic soil disinfestation for high tunnel specialty crop production systems in the U.S. Mid-Atlantic region. Acta Hortic. 1410, 133-142. https://doi.org/10.17660/ActaHortic.2024.1410.19

Donovan M, Ruiz-Menjivar J, Coolong T, Swisher ME. 2023. A scientometric review of the peer-reviewed research on high tunnels in the United States. Renewable Agriculture and Food Systems 38:e48. https://doi.org/10.1017/S1742170523000443

Fitzgerald C and M Hutton. 2012. Production practices and challenges with high tunnel systems in Maine. Journal of the National Association of County Agricultural Agents 5(2).

Foust-Meyer N and ME O’Rourke. 2015. High tunnels for local food systems: Subsidies, equity and profitability. Journal of Agriculture, Food Systems and Community Development. 5(20):27-38.  

Frey CJ, Zhao X, Brecht JK, Huff DM, Black ZE. 2020. High tunnel and grafting effects on organic tomato plant growth and yield in the subtropics. HortTechnology 30(4):492-503. DOI: 10.21273/HORTTECH04610-20

Gong T, Zhang X, Brecht JK, Black ZE, Zhao X. 2022. Grape tomato growth, yield and fruit mineral content as affected by rootstocks in a high tunnel organic production systems. HortScience 57(10):1267-1277. DOI: 10.21273/HORTSCI16553-22 

Gude KM, Pliakoni ED, Cunningham B, Ayub K, Kang Q, Rajashekar CB, Rivard CL. 2022. High Tunnel Coverings Alter Crop Productivity and Microclimate of Tomato and Lettuce. HortScience. 57(2):265–272. https://doi.org/10.21273/HORTSCI16208-21.

Hamal M, Roman C, Lewis Ivey ML, Miller SA, Gugino BK, Testen AL. 2025. Prevalence of soilborne pathogens in high tunnel tomato production in Ohio and nearby states. Plant Health Progress 26(3):344-252. https://doi.org/10.1094/PHP-01-25-0004-S

Ingwell LL, Avila-Ruiz DA, Foster R, Kaplan I. 2018. Tailoring insect biocontrol for high tunnels. Biological Control 123: 76-86. https://doi.org/10.1016/j.biocontrol.2018.04.012

Knewtson SJB, EE Carey and MB Kirkham. 2010a. Management practices of growers using high tunnels in the central Great Plains of the U.S. HortTechnology 20:639-645.

Lamont WJ. 2009.  Overview of the use of High Tunnels World Wide. HortTechnology 19(1): 25-29

Murariu OC, Brezeanu C, Jităreanu CD, Robu T, Irimia LM, Trofin AE, Popa L-D, Stoleru V, Murariu F, Brezeanu PM. 2021. Functional Quality of Improved Tomato Genotypes Grown in Open Field and in Plastic Tunnel under Organic Farming. Agriculture. 11(7):609. https://doi.org/10.3390/agriculture11070609.

Nian Y, Wu Q, Gao Z, Zhao X, Duan D, Carapezza G. 2025. Exploring the Adoption of High Tunnel System among Specialty Crop Growers: Perceptions, Use Experiences, Willingness to Pay, and Influencing Factors. HortScience. 60(12):2223–2231. https://doi.org/10.21273/HORTSCI18572-25.

Nian Y, Zhao R, Tian S, Zhao X, Gao Z. 2022. Economic Analysis of Grafted Organic Tomato Production in High Tunnels. HortTechnology. 32(5):459–470. https://doi.org/10.21273/HORTTECH05101-22. 

O’Connell S, C Rivard, MM Peet, C Harlow and F Louws. 2012. High tunnel and field production of organic heirloom tomatoes: Yield, fruit quality, disease and microclimate. HortScience 47(9):1283-1290.

Pandey S, Matocha CJ, Poffenbarger H, Jacobsen K. 2025. High Tunnels as a Unique Theatre for Investigating the Complex Causes of Yellow Shoulder Disorder in Tomatoes. Horticulturae. 11(7):773. https://doi.org/10.3390/horticulturae11070773. 

Perkus EA, Grossman HM, Pfeiffer A, Rogers MA, Rosen CJ. 2022. Exploring overwintered cover crops as a soil management tool in upper-midwest high tunnels. HortScience 57(2):171-180. https://doi.org/10.21273/HORTSCI15987-21

Pierre JF, Jacobsen KL, Wszelaki A, Butler D, Velandia M, Woods T, Sideman R, Grossman J, Coolong T, Hoskins B, da Silva ALBR, Ginakes P, Kleinhenz M, Zhao X, Rivard C, Rudolph RE. 2024. Sustaining soil health in high tunnels: A paradigm shift toward soil-centered management. HortTechnology 34(5): 595-603. https://doi.org/10.21273/HORTTECH05460-24

Reeve J and D Drost. 2012. Yields and soil quality under transitional organic high tunnel tomatoes. Hortscience 47(1):38-44.

Reid J, Machanoff C, Tucker C. 2023. Optimal Spacing of Grafted ‘Primo Red’ High Tunnel Tomato. HortTechnology. 33(4):381–386. https://doi.org/10.21273/HORTTECH05188-23.

Rosskopf, E.N., Di Gioia, F. 2023. New approaches to soil disinfestation for specialty crops. Handbook of Vegetable and Herb Diseases. https://doi.org/10.1007/978-3-030-35512-8_12-1.

Sharaf-Eldin MA, Yaseen ZM, Elmetwalli AH, Elsayed S, Scholz M, Al-Khafaji Z, Omar GF. 2023. Modifying Walk-In Tunnels through Solar Energy, Fogging, and Evaporative Cooling to Mitigate Heat Stress on Tomato. Horticulturae. 9(1):77. https://doi.org/10.3390/horticulturae9010077.

Torres-Quezada E, Gandini-Taveras RJ. 2023. Plant Density Recommendations and Plant Nutrient Status for High Tunnel Tomatoes in Virginia. Horticulturae. 9(10):1063. https://doi.org/10.3390/horticulturae9101063.

Turner Z, Velandia M, Rudolph RE, Wszelaki A, Schexnayder S. 2025. Grower preferences for high tunnel information sources: Evidence from a Kentucky high tunnel vegetable grower survey. Adv Ag Dev. 6(3):1–13. https://doi.org/10.37433/aad.v6i3.611. 

Wells OS and JB Loy. 1993. Rowcovers and high tunnels enhance crop production in the northeastern United States. HortTechnology 3(1):92-95.

Attachments

Land Grant Participating States/Institutions

MA

Non Land Grant Participating States/Institutions