Progress 08/01/22 to 07/31/23
Outputs
Target Audience:During this reporting period, our primary focus was on disseminating our research findings through the scientific community and reaching a broader audience. We engaged actively with the scientific community by presenting our work at the ASABE Annual Meeting and are in the process of publishing a study currently under review. This strategy aims to ensure that our research provides practical, research-based solutions to enhance spraying practices and advance agricultural sustainability. Our outreach specifically targeted fruit growers in Massachusetts and neighboring states, particularly small- and mid-scale farmers, as well as under-represented, low-income, and beginning farmers. These groups are essential beneficiaries of our research on eco-friendly biocidal drift reduction adjuvants using essential oils. During the reporting period, we reached an estimated 25 fruit growers through Extension activities, and research continued as planned. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Graduate student Joseph Heng attended ASABE Annual Meeting, held in Omaha, Nebraska (Jul. 9-12, 2023) Co-PD and graduate student Ajay Giri attended the Annual meeting of the Entomological Society of America, held in National Harbor, MD (Nov. 5-8, 2023). How have the results been disseminated to communities of interest?Graduate student Joseph Heng presented his research in the oral presentation in ASABE Annual Meeting. (Jul 2023) A peer reviewed paper based on the works in Aim 1 and 2 is submitted to Journal of Aerosol Science and is under review. Graduate student Ajay Giri described his research project among 17 undergraduate and graduate students at the University of Massachusetts (October 2023). What do you plan to do during the next reporting period to accomplish the goals?In the upcoming phase of our research, we will further our understanding of the drift reduction mechanism that will allow us to develop strategies to optimize the drift reduction performance. we will direct our attention towards assessing the biocidal properties of essential oils against two critical adversaries of apple cultivation: the Apple Maggot Fly (AMF) (Rhagoletis pomonella) and the fungal pathogen Apple Scab (Venturia inaequalis). Regarding the AMF, our investigation will primarily focus on determining whether essential oils function as attractants or deterrents and exploring potential synergies between these oils and insecticides. This exploration aims to enhance our understanding of how to effectively manage AMF infestations in apple orchards. Concurrently, our study will delve into combating Apple Scab through in vitro experimentation. Specifically, we will examine the impact of various compounds, including carvacrol, copper nanoparticles, fungicides, and their combinations, on the germination of Venturia inaequalis conidia. This investigation seeks to elucidate the minimum inhibitory concentration (MIC) of each compound, providing valuable insights into novel strategies for mitigating the detrimental effects of Apple Scab on apple crops. Through these multifaceted approaches, we aim to contribute to the development of sustainable and effective solutions for pest and pathogen management in apple cultivation.
Impacts
What was accomplished under these goals?
Towards Aim 1 and 2 , main studies are summarized here. Study 1: Evaluation of Spray Performance We assessed the spray performance of various oil-in-water emulsion formulations by capturing high-speed videos of the spray patterns and measuring droplet size distributions. We compared essential oils (D-limonene, carvacrol, alpha-pinene, eugenol) and the natural surfactant quillaja saponin with commonly used vegetable oils (methylated seed oil, soybean oil, medium-chain triglyceride) and synthetic surfactants (Tween 80, SDS). The shadow sizing method (DynamicStudio, Dantec Dynamics) using a high-speed camera (Phantom VEO640L, Vision Research) was identified as the optimal technique for measuring droplet sizes. We maintained a constant oil concentration of 0.5 wt% and an emulsifier concentration of 0.025 wt%, controlling droplet diameters to approximately 3 micrometers. Results indicated that some essential oil-surfactant combinations increased median droplet size, thus reducing spray drift potential compared to water sprays, while others did not show a significant reduction. Study 2: Investigation of Spray Atomization Mechanisms We explored the mechanisms behind spray atomization of oil-in-water emulsions to understand the varying spray drift reduction abilities of different essential oils. We measured the equilibrium and dynamic interfacial tensions of the formulations between the oil and aqueous phases and between the emulsion and air. Our findings revealed that essential oils with lower equilibrium interfacial tensions (e.g., carvacrol and eugenol) generally provided better spray drift reduction. This insight will help guide the selection of essential oils for agricultural sprays based on their physicochemical properties and biocidal effects. However, the presence of surfactants, such as SDS, was found to negatively impact drift reduction. Study 3: Characterization of Spray Droplet Sizes Under External Airflow We began characterizing spray droplet size distributions under external airflow conditions generated by a propeller (XRotor Pro X6, Hobbywing) to simulate real-world UAV spraying scenarios. Air velocities at different propeller speeds (1000, 2000, 3000 rpm) were measured using laser Doppler anemometry (Dantec Dynamics). Spray droplet sizes were mapped in 2D using phase Doppler anemometry (Dantec Dynamics) at various propeller speeds. Results demonstrated that external airflow significantly affects droplet lateral movement and coverage. For water sprays, median droplet size increased with air velocity (up to 7 m/s), whereas for carvacrol emulsion sprays, the median droplet size decreased with increasing air velocities. These findings emphasize the importance of accounting for air velocity in estimating spray droplet sizes and drift potential. Towards Aim 3 The objective of this study was to investigate the categorization of essential oils (Carvacrol, D-limonene, and Eugenol) as attractants or deterrents for Spotted-wing drosophila (SWD) (Drosophila suzukii) and apple maggot fly (AMF) (Rhagoletis pomonella), and assess their synergistic effects with insecticides, aiming to provide safer alternatives for pest control during the critical fruit ripening period. The study explores the interactions between essential oil formulations and insecticides on Spotted-wing drosophila (SWD) and apple maggot fly (AMF), two pests with strong ovipositors that can puncture ripening fruits. Growers, aiming for zero tolerance to infestations, traditionally rely on frequent insecticide applications, but this is often discontinued during the critical fruit ripening period. The research categorizes essential oils (Carvacrol, D-limonene, and Eugenol) as either attractants or deterrents and investigates their synergistic effects with insecticides. Three experiments are conducted: a dual choice bioassay (Experiment 1) examines pest behavior, an oviposition study (Experiment 2) assesses egg-laying on essential oil-treated substrates, and a mortality study (Experiment 3) evaluates the biocidal efficacy of diluted essential oils, aiming to provide insights into their potential as safer alternatives for pest control during fruit ripening. The initial findings from experiment 1 indicate significant variations in attractiveness among different treatments towards the spotted-wing drosophila (SWD). At 48 hours (p 0.023) and 72 hours (p 0.0105), the control (Blank diet) exhibited significantly higher attractiveness compared to Carvacrol 0.5% + diet. Moreover, at 72 hours (p 0.0204), the Blank diet treatment was notably more attractive than Limonene 0.5% + diet. Notably, across multiple time points (24hr, 48hr, and 72hr), Eugenol 0.5% + diet displayed significantly higher attractiveness (P 0.0006, P 0.0442, and P 0.05 respectively) than the blank diet. Moreover, when the Blank diet was paired with a high concentration of essential oils (5%), SWD showed significantly more attraction towards the Blank diet. Experiment 2 demonstrated that blueberries treated with distilled water yielded an average emergence of 12 SWD, whereas those treated with Carvacrol 0.05% resulted in 10 SWD after a two-week incubation period. Conversely, no emergence was observed in blueberries treated with Insecticide (Entrust: Spinosad) or a combination of Insecticide and Carvacrol 0.5%. In Experiment 3, blueberries treated solely with Insecticide or in combination with Carvacrol 0.5% exhibited statistically similar mortality rates against SWD. Interestingly, a 5% concentration of Carvacrol resulted in a mortality rate of 57.3% among SWD. Conversely, the lower mortality rates (<3%) were observed in blueberries treated with Carvacrol 0.5% and DI water, which were statistically similar. These results highlight the differential effectiveness of various treatments in deterring SWD infestation, with implications for pest management strategies in agricultural settings.
Publications
- Type:
Journal Articles
Status:
Submitted
Year Published:
2024
Citation:
Heng J, Bechard S, Lach D, Rothstein J, Wang M, Ubal S, McClements DJ, Corvalan CM, Lu J. Evaluating essential oils as biocidal anti-drift adjuvants for safe and sustainable agricultural spray enhancement. Journal of Aerosol Science.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2023
Citation:
Heng J, and Lu J., Effect of UAV downwash airflow on agriculture spray drift potential. ASABE Annual Meeting Omaha, Nebraska July 9-12, 2023
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