Optimizing mesotunnel systems for sustainable production of cucurbit crops

Progress report for LNC18-404

Project Type: Research and Education
Funds awarded in 2018: $193,962.00
Projected End Date: 09/30/2021
Grant Recipient: Iowa State University
Region: North Central
State: Iowa
Project Coordinator:
Dr. Mark Gleason
Iowa State University
Expand All

Project Information

Summary:

Cucurbit crop growers in the North Central Region struggle to control cucumber beetles and the bacterial wilt pathogen they spread. The bacterium kills plants, depresses yield, and drains profits. Insecticide sprays are widely used against the cucumber beetles but damage pollinators and other beneficial insects, so their sustainability is in question. Muskmelon is highly susceptible to bacterial wilt, and organic growers often avoid planting this crop because yield losses can exceed 80%. Alternative management tactics such as biochemical lures, perimeter trap cropping, delayed planting, and crop rotation have not been reliably effective. Low tunnels covered by spunbond polypropylene fabric work well until they are removed to allow pollinator access, but then muskmelon can collapse and die from mid- to late-season wilt outbreaks. We have been testing an innovative variation on the protective tunnel theme that we call mesotunnels. Mesotunnels are more than twice as tall as low tunnels and are covered by a breathable nylon-mesh fabric that remains in place all season, with bumble bee colonies inserted underneath for pollination. In small-plot trials in Iowa in 2016 and 2017, mesotunnels increased marketable yield of organic muskmelon by an average of 450% compared to low tunnels or insecticide-only treatments – without using any insecticides. This approach therefore has promise to deliver consistently high marketable yields without the risks associated with insecticide use – a change that could open up new growing and marketing opportunities for organic cucurbit growers. Our proposed project will take the essential next steps to make mesotunnels into a workable alternative for North Central Region growers. Two years of field experiments under organic management will assess living mulches for weed control and soil quality improvement, and optimize the efficiency of purchased bumble-bee colonies for pollination under commercial-size mesotunnels (Objective 2). We will compare profitability of the mesotunnel system to current management strategies and work closely with growers to understand the factors that impact their views of the new system (Objective 2). Our intensive outreach program, mixing on-farm demonstration trials and field days in Iowa and Missouri with electronic features such as webinars and an online manual for growers, will ensure that the project’s messages reach cucurbit growers throughout the NC Region (Objective 3). Our results will have application to additional cucurbit crops that are susceptible to bacterial wilt, and for conventional producers seeking to minimize reliance on insecticides.

Project Objectives:

• 250 NC Region muskmelon growers become aware of the potential value of mesotunnels to suppress pest insects and bacterial wilt.
• 80 growers learn how to use mesotunnels on their cucurbit crops
• noo growers understand the economic tradeoffs of using mesotunnels for cucurbit production.
• 60 growers (including 30 organic growers) plan to try mesotunnel systems on their own farms within 2 years.
• 30 growers try mesotunnels in their muskmelon fields during the project period.

Introduction:

Bacterial wilt, caused by Erwinia tracheiphila, causes yield losses for cucumbers and muskmelon that can exceed 80%, and also decimates pumpkin, winter squash, and zucchini. Bacterial wilt-resistant cultivars of muskmelon and cucumber are nearly non-existent.Stopping cucumber beetles is currently the only effective way to combat bacterial wilt on highly susceptible crops like muskmelon, honeydew, and cucumber. Neonicotinoid insecticides are widely used against striped cucumber beetle (Acalymma vittatum) and spotted cucumber beetle (Diabrotica undecimpunctata). However, these and other pesticides weaken or kill pollinators and reduce populations of insectivorous birds. Synthetic pyrethroid insecticides are also widely used but kill natural enemies. Yield losses from bacterial wilt jeopardize growers’ sustainability. CSA customer dissatisfaction, unfulfilled contracts with cooperatives, and quality issues with wholesale clients can threaten economic viability and resilience of cucurbit growers. This problem is especially acute for organic growers because there are no consistently effective organic management strategies against bacterial wilt. With funding from NIFA Organic Transitions (2015–2018), our ISU team began evaluating an innovative protection system called “mesotunnels” to overcome disadvantages of low tunnels. Mesotunnels are covered with a tough nylon-mesh fabric that is far more durable and breathable than spunbond fabrics. Mesotunnels are also much taller (3.5 ft.) than low tunnels (1.5 ft), so there is more room for plant growth and no overheating of plants. Unlike low tunnels, mesotunnels can protect cucurbit crops for the entire growing season. Despite encouraging preliminary results, several key questions must be answered before mesotunnels can be recommended for use by growers:

  • Can mesotunnels be scaled up effectively from small-plot experiments to commercial-size muskmelon plantings?
  • What is the most cost-effective way to deploy purchased bumble bee colonies for pollination under full-season mesotunnels?
  • Can living mulches be used to control weeds under mesotunnels while also enhancing soil health?
  • Will higher and more consistent marketable yields increase profits despite the higher cost of mesotunnels?

Our 2-state (Iowa and  Missouri), 2-year project will answer these questions in organic muskmelon, for which bacterial wilt is especially threatening, with an integrated program of field experiments, economic and stakeholder assessments, on-farm demonstration trials, and outreach. 

Research

Hypothesis:
  1. In 30-ft-long mesotunnel plots of organic muskmelon, each of 2 seeding rates of teff (4 and 8 lb/A) will a) suppress weeds between rows as effectively as weed fabric and b) result in marketable yield equivalent to that of the weed-fabric treatment.
  2. In 150-ft-long mesotunnel plots of organic muskmelon, inserting a purchased hive of bumblebees inside mesotunnels during flowering will result in higher marketable yield than either a) opening the ends of the tunnels or b) removing the tunnel fabric for 2 weeks during bloom.
  3. In 150-ft-long mesotunnel plots of organic muskmelon, either a) removing mesotunnel fabric or b) opening the ends of the tunnels for 2 weeks during flowering will result in increased incidence of bacterial wilt compared to a treatment in which a bee box is inserted under the mesotunnel fabric.
Materials and methods:

Weed management with mulches in mesotunnels. At the Iowa State University Horticulture Research Station near Gilbert, Iowa, during 2020, muskmelon (cv. Athena) seedlings were transplanted into 30-ft-long, 3-row subplots spaced at 6 ft on black plastic mulch, under full-season mesotunnels (3.5-ft-tall tunnels with ProtekNet nylon-mesh fabric supported on steel-conduit hoops). One bumblebee box was placed during bloom in each subplot for pollination. Four mulch treatments, arranged in a randomized complete block design, were applied to bare-soil strips between black plastic: 1) teff living mulch (seeded at 4 lb/A), 2) teff at 8 lb/A (both seeded at the time of transplanting the crop), 3) plastic landscape fabric and 4) bare ground (control). Rationales for using these treatments: 1) they encompass a wide range of the weed suppression tactics used by organic cucurbit-crop growers in the North Central Region; and 2) weed control under mesotunnels poses special challenges because there are no opportunities for mowing or other organic tactics during the growing season, so we sought to test tactics with potential to provide full-season weed suppression. Yield data were taken on the center row of each 3-row subplot; the number and weight of marketable fruit were recorded at harvest. Above-ground weed biomass was assessed immediately before crop harvest began.

Pollination strategies in mesotunnels. At the Iowa State University Horticulture Research Station near Gilbert, Iowa, during 2020, muskmelon (cv. Athena) seedlings were transplanted into 150-ft-long, 3-row subplots on 6-ft row spacing in a randomized complete block design. All plots were covered with mesotunnels (3.5 ft tall, with nylon-mesh fabric (ProtekNet) on steel-conduit hoops) immediately after transplanting. Treatments were: 1) a bumble bee hive (Koppert Inc.) per subplot (full-season tunnels); 2) tunnel ends opened for two weeks during bloom, then  replaced (open-ends treatment); and 3) ProtekNet fabric was removed for 2 weeks during bloom, then replaced (on-off-on treatment). The rationale for selecting these treatments was that we realized that some growers might not be able to purchase bees or they might be too costly, so we wanted to include lower-input-cost alternatives. Visual observations of bee activity on muskmelon flowers were made twice a day in all treatments between 8:00 and 11:00 AM on three days per week during two weeks after female flowers appeared. Disease incidence and severity were rated on the center row of each subplot and recorded weekly. Number and weight of marketable fruit data were recorded at harvest on the center row of each subplot.

Research results and discussion:

Weed management with mulches in mesotunnels. RESULTS: Marketable yield for landscape fabric was about twice as high as for the other three treatments, although teff suppressed weeds almost as well as landscape fabric. DISCUSSION: The yield penalty from teff in both crops (compared to landscape fabric) was attributed to root competition with the crop for nutrients, water, and sunlight during an abnormally dry growing season. Although teff did a great job on weed suppression, its vigor and drought tolerance made it a potent competitor with the muskmelon crop.  It is clear that if teff can be useful for suppressing wed growth and the weed seed bank, its vigor must be suppressed, possibly by mowing the teff strips during bloom. 

Pollination strategies in mesotunnels. RESULTS: Marketable yield was highest for the full-season mesotunnel treatment, intermediate for the open-ends treatment, and lowest for the on-off-on treatment. Bacterial wilt incidence was slightly higher in the on-off-on treatment than the other treatments, but its impact on yield was unclear. A fungal disease, Alternaria leaf spot, was observed late in the season; severity of this disease was low and did not differ among treatments. DISCUSSION: The yield boost for the full-season treatment compared to the other treatments suggests that it has potential for organic producers. However, an economic analysis is being conducted to determine which treatment is most cost-effective, and some producers may not wish to purchase and handle bee hives even if this treatment is the most attractive economically.

Research conclusions:

Conclusions for Year 2 report:

  • Our search for a living mulch in the soil strips between crop-row strips that suppresses weed growth but does not compete with the muskmelon crop continues. Year 1 results using annual rye and clover reflected other years in that these living mulches did not emerge and establish rapidly enough to meaningfully suppress weeds from the very large weed seed bank at the ISU Horticulture Station. In Year 2, the switch to teff as a living mulch resulted in excellent weed control but a yield penalty for muskmelon due to competition by teff. Over the next 2 field seasons (funded by a grant to PI Gleason from NIFA-OREI), we will continue to assess teff as a living mulch, with its growth suppressed by mid-season mowing. Landscape fabric provided excellent weed control with no yield drag, but requires an additional off-farm input. It can be stored and re-used, providing the labor and space for this are available.
  • The full-season pollination strategy, with mesotunnels remaining in place all season and bumble bee hives inserted underneath for pollination, was the most promising treatment from a marketable yield standpoint. An ongoing economic analysis is aiming at determining cropping scenarios (e.g., scale of muskmelon cultivation, number of years for which the nylon-mesh covering can be re-used, and price for purchased hives) under which the full-season pollination strategy can be advantageous for organic muskmelon growers.
Participation Summary

Education

Educational approach:

On-farm demonstration trials.

  • Iowa. An on-farm trial was held at Middle Way Farms, Grinnell, Iowa; grower-cooperator was Jordan Scheibel.

    This project focused on the use of mesotunnels for integrated insect management in sustainable vegetable production. An on-farm trial grower-collaborator trial was established at Middle Way Farms, Grinnell, IA. The farm is owned and operated by Jordan Scheibel. The farm is a small, chemical-free, direct market vegetable farm just outside of Grinnell, Iowa, selling seasonally May through December to customers in Grinnell, Newton, and the surrounding area.

    Growing season: The research focused on utilizing watermelon as a crop to test and compare ProtekNet vs. no-cover treatment. Due to inclement weather and a wet spring planting was delayed. Three week old watermelon seedlings were transplanted on raised black plastic mulch beds on 3 July 21. Treatments included a no-cover and ProtekNet. The ProtekNet netting was installed on 6 July 2020. Each treatment was 40 ft. long and there were three replications for each treatment. ProtekNet were removed on 9 August 2020 to facilitate pollination. One-time harvest was conducted on 13 October 2020.

    There was no difference in marketable fruit number or weight between treatments (Table 1). Marketable fruit count ranged from 21 to 23 and weight ranged from 93.2 to 99.4 lbs. Insect damage was recorded on the fruit at the time of harvest but there were no differences between treatments. Overall, the yield from the entire study was low and this is due to the damage caused to the plants by Derecho storm which took place on 10 August 2020. Many of the plants had severed stems and were damaged by the hail that was part of the Derecho.

    Air temperature data was continuously collected during the growing season using Hobo sensors (Onset Data Loggers, Bourne, MA). There were no significant differences in air temperature between treatments for the month of July (Table 2). There were significant differences in light intensity between treatments for the month of July with Protek net reducing light intensity by 25% (Table 2). We also collected grower feedback on plant vigor, difference in insect damage and pest pressure, ease of installation, management challenges, and cost associated with Protek net treatments.

    Based on the feedback from Jordan, ProtekNet treatments could have provided the benefit of insect protection if the crop was planted earlier, typically beginning of June. In 2020, the crop was planted in July when major insect pests had already taken hold on other crops. Also, since the farm was not able to reinstall the ProtekNet after pollination, all treatments were exposed to the insects and other environmental factors. The major setback was the Derecho event which did not allow for a fair comparison of the treatments as the entire study was heavily impacted.

    Another challenge was to manage weeds in the ProtekNet treatment (Fig. 2). Although the farm applied straw mulch between rows, the thickness of the application was not enough to stop weeds from emerging. One of the strategies moving forward could be the use of weed fabric between rows where Protek net treatments are being installed.

  • Missouri. An experiment was conducted with 'Athena' muskmelon at the Organic Farm of Lincoln University in summer 2020. The experimental design was a randomized complete block design with 2 treatments (non-covered control and mesotunnel); 3 sections; 3 blocks per section and 10 plants per block. Transplanting took place on June 12. Cucumber beetle populations were extremely low, and bacterial wilt symptoms were not evident in the field. Statistical analysis of the yield data has not been done yet.

Field days.

  • The Iowa field day at the ISU Hort Research Station, scheduled for August 2020, was canceled due to the pandemic.
  • In Missouri, a field day that was held near Jefferson City, MO, on July 12, 2020, included a grower tour of the NCR-SARE demonstration plot.

Meeting presentations.

Dr Ajay Nair (ISU co-PI) presented two formal talks relating project purposes and results:

    1. PFI Annual Conference: Grower panel

    Date: 01/21/2021

    Number of attendees: 35

     

    1. Title: Integrated pest management in sustainable vegetable production systems

    Conference: Iowa Specialty Producers Conference

    Date: 01/20/2021

    Number of attendees: 19

     

    1. Title: Specialty Crop Production: Grower panel

    Conference: Iowa Specialty Producers Conference

    Date: 01/20/2021

    Number of attendees: 15

    4. Cheek, M., and Eaton, T. 2021. Mesotunnels as an alternative to insecticides to control cucumber beetles in muskmelon. Poster presentation, Great Plains Growers Conference, February 12-13, 2021.

          5. Gleason, M.L. 2021. Mesotunnels: exploring a new approach for organic cucurbits. PowerPoint presentation, Great Plains Growers Conference, February 12, 2021.

Mr. Mphande also submitted Iowa State two research reports (one on each field experiment), summarizing 2020 results, that are awaiting publication by the ISU Agriculture Experiment Station as part of their Farm Reports series (they have not yet been assigned URLs). These research reports are intended for grower use.

Electronic resources.

  • Project website entitled "The Current Cucurbit" (https://www.cucurbit.plantpath.iastate.edu) includes blog posts, videos, and reports developed jointly for the the NCR-SARE project and the NIFA-OREI project during 2020.
    • Gleason, M.L. "What's a mesotunnel, and what's it good for"? July 24, 2020. Blog post. (https://www.cucurbit.plantpath.iastate.edu/post/whats-mesotunnel-and-whats-it-good)
    • Pethybridge, S. "Mesotunnels: next best tool for organic cucurbit growers in the Northeast U.S.?" August 14, 2020. Blog post. (https://www.cucurbit.plantpath.iastate.edu/post/mesotunnels-next-best-tool-organic-cucurbit-growers-northeastern-us)
    • Gonzalez, J. "Planning for success: IPM approaches in organic cucurbit production" August 28, 2020. Blog post. (https://www.cucurbit.plantpath.iastate.edu/post/planning-success-ipm-approaches-organic-cucurbit-production)
    • Chen, N., and Zhang, W. "How do we assess the economic efficiency of mesotunnels? An economist's take" September 18, 2020. (https://www.cucurbit.plantpath.iastate.edu/post/how-do-we-assess-economic-efficiency-mesotunnels-economists-take)
    • Gonthier, D., and Bessin, R. "Balancing pollination and pest control in mesotunnel cucurbit systems" October 2, 2020. (https://www.cucurbit.plantpath.iastate.edu/post/balancing-pollination-and-pest-control-mesotunnel-cucurbit-systems)
    • Badilla, S. "Optimizing weed control under mesotunnel systems: Iowa State's 2020 experience with acorn squash" October 16, 2020. (https://www.cucurbit.plantpath.iastate.edu/post/optimizing-weed-control-under-mesotunnel-systems-iowa-states-2020-experience-acorn-squash)
    • Mphande, K. "A look at 2020 muskmelon trial results from Iowa State University (ISU)" October 30, 2020. (https://www.cucurbit.plantpath.iastate.edu/post/look-2020-muskmelon-trial-results-iowa-state-university-isu)
    • Morton, L.W. "Crop diversification as a risk management strategy" November 13, 2020 (https://www.cucurbit.plantpath.iastate.edu/post/crop-diversification-risk-management-strategy)
    • Gleason, M.L. "Summary of 2020 season results" Notes from OREI cucurbit mesotunnel virtual project meeting with grower Advisory Panel, October 2, 2020. (https://www.cucurbit.plantpath.iastate.edu/files/inline-files/OREI%20Annual%20Virtual%20Meeting%232%20Highlights%20final%20-%202020%20%28untraceable%20ver%29.pdf)
    • Morton, L.W., Cheng, N., Diggins, K., and Gonzalez, J. "Technical report: cucurbit growers' perceptions of mesotunnel production systems" January 27, 2021. (https://www.cucurbit.plantpath.iastate.edu/files/inline-files/Growers%20perceptions%20-%202020%20final%20report.pdf)
    • Nair, A., and Gleason, M.L. "Summary of the 2020 on-farm trials from Iowa: effect of ProtekNet mesotunnels on cucurbit crop production and microclimate management" (https://www.cucurbit.plantpath.iastate.edu/files/inline-files/On-farm%20trials%20Iowa%202020.pdf)
    • Gleason, M.L. "Summary of the 2020 field trial results" (https://www.cucurbit.plantpath.iastate.edu/files/inline-files/OREI%203-state%20field%20trial%20summary%202020.121.pdf)Surveys
    • Zhang, W., and Chen, N. 2021. "The OREI cucurbit crops project year 1 and Whole Team/Advisory Panel/Cooperating Grower survey" February 2021 (https://www.cucurbit.plantpath.iastate.edu/files/inline-files/OREI_Year_1_Survey_Report_Feb2021.pdf)

Project Activities

On-farm demonstration trials with mesotunnels and cucurbit crops

Educational & Outreach Activities

14 Consultations
25 Curricula, factsheets or educational tools
2 On-farm demonstrations
1 Online trainings
3 Published press articles, newsletters
2 Tours
4 Webinars / talks / presentations
3 Workshop field days

Participation Summary:

90 Farmers
5 Ag professionals participated
Education/outreach description:

On-farm demonstration trials.

  • Iowa. An on-farm trial was held at Middle Way Farms, Grinnell, Iowa; grower-cooperator was Jordan Scheibel.

    This project focused on the use of mesotunnels for integrated insect management in sustainable vegetable production. An on-farm trial grower-collaborator trial was established at Middle Way Farms, Grinnell, IA. The farm is owned and operated by Jordan Scheibel. The farm is a small, chemical-free, direct market vegetable farm just outside of Grinnell, Iowa, selling seasonally May through December to customers in Grinnell, Newton, and the surrounding area.

    Growing season: The research focused on utilizing watermelon as a crop to test and compare ProtekNet vs. no-cover treatment. Due to inclement weather and a wet spring planting was delayed. Three week old watermelon seedlings were transplanted on raised black plastic mulch beds on 3 July 21. Treatments included a no-cover and ProtekNet. The ProtekNet netting was installed on 6 July 2020. Each treatment was 40 ft. long and there were three replications for each treatment. ProtekNet were removed on 9 August 2020 to facilitate pollination. One-time harvest was conducted on 13 October 2020.

    There was no difference in marketable fruit number or weight between treatments (Table 1). Marketable fruit count ranged from 21 to 23 and weight ranged from 93.2 to 99.4 lbs. Insect damage was recorded on the fruit at the time of harvest but there were no differences between treatments. Overall, the yield from the entire study was low and this is due to the damage caused to the plants by Derecho storm which took place on 10 August 2020. Many of the plants had severed stems and were damaged by the hail that was part of the Derecho.

    Air temperature data was continuously collected during the growing season using Hobo sensors (Onset Data Loggers, Bourne, MA). There were no significant differences in air temperature between treatments for the month of July (Table 2). There were significant differences in light intensity between treatments for the month of July with Protek net reducing light intensity by 25% (Table 2). We also collected grower feedback on plant vigor, difference in insect damage and pest pressure, ease of installation, management challenges, and cost associated with Protek net treatments.

    Based on the feedback from Jordan, ProtekNet treatments could have provided the benefit of insect protection if the crop was planted earlier, typically beginning of June. In 2020, the crop was planted in July when major insect pests had already taken hold on other crops. Also, since the farm was not able to reinstall the ProtekNet after pollination, all treatments were exposed to the insects and other environmental factors. The major setback was the Derecho event which did not allow for a fair comparison of the treatments as the entire study was heavily impacted.

    Another challenge was to manage weeds in the ProtekNet treatment (Fig. 2). Although the farm applied straw mulch between rows, the thickness of the application was not enough to stop weeds from emerging. One of the strategies moving forward could be the use of weed fabric between rows where Protek net treatments are being installed.

  • Missouri. An experiment was conducted with 'Athena' muskmelon at the Organic Farm of Lincoln University in summer 2020. The experimental design was a randomized complete block design with 2 treatments (non-covered control and mesotunnel); 3 sections; 3 blocks per section and 10 plants per block. Transplanting took place on June 12. Cucumber beetle populations were extremely low, and bacterial wilt symptoms were not evident in the field. Statistical analysis of the yield data has not been done yet.

 

Learning Outcomes

25 Farmers reported changes in knowledge, attitudes, skills and/or awareness as a result of their participation
10 Agricultural service providers reported changes in knowledge, skills, and/or attitudes as a result of their participation
Key areas taught:
  • IPM for organic muskmelon growers in Iowa and Missouri

Project Outcomes

4 Farmers changed or adopted a practice
Key practices changed:
    1 New working collaboration
    Recommendations:
    • Weed management in mesotunnel systems. After one field season of testing, we have mixed feelings about the value of using teff as a living mulch in the soil strips between crop rows. Although it grows vigorously and chokes out weeds effectively, it also competed with muskmelon for water and nutrients in the dry 2020 growing season in Iowa. Teff is a dryland cereal which develops a very extensive root system. In a dry year with a crop who primary water source is drip lines, teff grew toward the drip lines and took much of the water intended for crops. Soil type may be a factor in this outcome; for example, University of Kentucky researchers have has good results with teff as a living mulch in cucurbit crops, but their soils are much higher in clay content and thus water retention than the silty loams of central Iowa. Thus, the suitability of teff as a living mulch may vary regionally, by soil type, and with rainfall conditions during the growing season. It is possible that mowing teff in mid-season could reap the weed-control benefits of this vigorous cereal while minimizing its yield-depressing impact on cucurbit crops. Plastic landscape fabric is a highly effective weed control alternative for the soil strips in organic cucurbit crops, but adds to costs for off-farm inputs and is laborious and cumbersome to store between growing seasons.
    • Pollination in mesotunnel systems. Our research results in Iowa under NCR-SARE, NIFA Organic Transitions, and NIFA OREI funding over the past 7 years have led to the preliminary conclusion that the choice of optimal pollination strategy may depend on the cucurbit crop. For organic muskmelon, the "full season" strategy, which keeps mesotunnels closed all season except for inserting purchased bumble bees, out-yielded  strategies that temporarily removed the nylon netting (entirely or just the ends of the rows) for 2 weeks to allow pollination had lower marketable yield. In contrast, acorn squash has the highest yield when the ends of the tunnels were opened for 2 weeks. We attribute this difference in crop performance to two factors. The first one is differences in crop-canopy architecture. Acorn squash plants fill the mesotunnel space so rapidly that bees from purchased hives cannot locate open flowers, whereas muskmelon plants remain lower in canopy profile, with much less impedance of bumble bee flight in the closed tunnels. Second, muskmelon in Iowa are at much greater risk than acorn squash of losses due to bacterial wilt, since the strains of the bacterial wilt pathogen that are highly pathogenic on squash are uncommon in the Upper Midwest. For these reasons, the full-season mesotunnel strategy may be more suitable for muskmelon than acorn squash. Ongoing field experiments (2021 and 2022), economic analysis, and on-farm grower trials will help to clarify which pollination strategies have the most potential for each crop in Iowa.

     

    Information Products

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.