Progress report for SW24-012
Project Information
Compared to conventional synthetic pesticides, use of low-risk and organically certified pesticides (L-R & OCPs) in greenhouse crop production systems is hampered by comparatively slow and inconsistent performance and short residual effect. Accordingly, a higher number of applications is needed to achieve pest control, which leads to increase in costs of pest management and higher use of pesticides. To promote adoption of L-R & OCPs in greenhouse crop production systems, it is of paramount importance to develop solutions and educate growers about ways to optimize their performance and residual effects. The hypothesis of this 3-year project is that L-R & OCPs for use in greenhouse crop production systems can be made significantly more effective and lead to significantly better management of spider mites and western flower thrips when deployed in concert with plasma activated water (PAW). This hypothesis will be addressed based on the following five project objectives:
Objective 1: Experimental optimization of PAW
Objective 2: Experimental integration of PAW and L-R & OCPs
Objective 3: Testing in greenhouses
Objective 4: Educational outreach
Objective 5: Academic capacity building
These objectives are linked to seven project outcomes: 1) research publications, 2) trade journal publications, 3) conference presentations, 4) project-specific website pages, 5) demonstration videos, 6) adoption metrics, and 7) academic course curriculum. This project is predicted to demonstrate important environmental and social benefits, as it will lower the adoption threshold for use of L-R & OCPs in greenhouse crop production systems by showing that their integration with PAW can significantly increase their ability to control key pest populations. This proposal is well-supported by preliminary data and by the greenhouse crop production industry. This proposal includes comprehensive educational and academic capacity building, and it will promote technological innovation and science-based careers for aspiring young scientists with interest in sustainable agriculture. Moreover, the project team will create project specific pages with videos, weblinks, photos, and pdf documents on PI Nansen’s website (http://chrnansen.wix.com/nansen2). Most materials posted will be translated into Spanish. Web pages will be linked directly to extension outlets managed by relevant stakeholder organizations, including: Plant California Alliance, the Northeast Organic Farming Alliance Greenhouse Lighting and Systems Engineering consortium, and California Tomato Research Institute.
Objective 1: Experimental optimization of PAW (plasma activated water)
Objective 2: Experimental integration of PAW and L-R & OCPs (low-risk and organically certified pesticides)
Objective 3: Testing in greenhouses
Objective 4: Educational outreach
Objective 5: Academic capacity building These objectives are linked to seven project outcomes: 1) research publications, 2) trade journal publications, 3) conference presentations, 4) project-specific website pages, 5) demonstration videos, 6) adoption metrics, and 7) academic course curriculum. This project is predicted to demonstrate important environmental and social benefits, as it will lower the adoption threshold for use of L-R & OCPs in greenhouse crop production systems by showing that their integration with PAW can significantly increase their ability to control key pest populations. This proposal is well-supported by preliminary data and by the greenhouse crop production industry. Additionally, the project team already has trained personnel and a fully operational cold plasma system (worth >$80,000), which constitutes highly unique and significant in-kind contribution to this project.
Cooperators
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Research
Objective 1: Experimental optimization of PAW
A MSc student, Mr Yugeng Zou, is currently working on this project objective. We have identified storage time of PAW as being a key issue - that the physico-characteristics of PAW (pH, electric conductivity, total dissolved solids, salinity, and reactive potential of oxygen and nitrogen reactive species) are not stable over time. In addition, we have discovered that use of bases to control pH can improve storage stability.
Objective 2: Experimental integration of PAW and L-R & OCPs
Experimental plans for data collections from studies involving two-spotted spider mites and western flower thrips on several host plants (gerbera, Chrysanthemum, bean, and tomato) have been made and will be executed in coming months.
We have discovered that PAW is highly dynamic over time - that several physico-characteristics are changing, even 4-6 weeks after PAW was produced. Thus, stabilizing PAW is critical and something we need to resolve before moving to in-depth testing of PAW as insecticide carrier.
Research Outcomes
Our project website is continuously updated with relevant information about plasma activated water and its potential in sustainable controlled environment crop production: Cold plasma | new-nansen2
Although submitted before onset of this project (and WSARE therefore not mentioned in the acknowledgements), we have recently published an article in which we conclude that (Journal of Pest Science, https://doi.org/10.1007/s10340-024-01791-0): Results presented in this study provide comprehensive support to the hypothesis that indirect effects of supplementary PAW irrigation significantly reduce host plant suitability to two-spotted spider mites. PAW 6.0 may be slightly better than PAW 9.4, and this difference in performance is discussed in this study. Applications of PAW as supplementary irrigation are likely highly compatible with other IPM tactics and should be considered an innovative and sustainable component in twenty-first-century pest management.
Education and Outreach
Participation Summary:
PI Nansen teaches ENT110 Arthropod Pest Management in Fall quarters at UC Davis. This is a 5-credit course with two 80 min lectures and 6 hours lab sessions (on Fridays) each week. Several lectures include reading assignments and class discussions related to insecticides, and spray applications is the main topic of two of the 10 weekly lab sessions. The students are introduced to the basic concepts of, including: lethal dosages, behavioral resistance, physiological resistance, modes of action, IRAC groups, insecticide formulations, application methods, spray drift, and resistance evolution. It is in this context, the students are introduced to PAW as a potential carrier and booster of of low-risk and organically certified pesticides (L-R & OCPs) in greenhouse crop production systems.
Education and Outreach Outcomes
PI Nansen teaches ENT110 Arthropod Pest Management in Fall quarters at UC Davis. This is a 5-credit course with two 80 min lectures and 6 hours lab sessions (on Fridays) each week. He has published a simple teaching tool for university students and others to learn about the likelihood of resistance evolution to take place, when arthropod pest management is exclusively based on insecticides (Nansen C. 2022. An interactive teaching tool describing resistance evolution and basic economics of insecticide-based pest management. Insects, 13, 169. https://doi.org/10.3390/insects13020169). PI Nansen has also published on the importance of experimental research and of higher educational institutions facilitating active learning through living laboratories (Nansen C. 2024. Living laboratories, student empowerment, and urban sustainability. Sustainability. 16, https://doi.org/10.3390/su16103902). These outputs are used to emphasize the importance of applied research outcomes from this project.