- Author: Alireza Pourreza
UC Digital Agriculture Program's innovative spray backstop system reduces airborne pesticide drift by 78% in almond orchards– a big step forward for improving air quality and working conditions in California's agricultural production areas.
The Issue
Pesticide drift is a significant concern, especially in California's almond orchards. It's not just an environmental issue. Pesticide drift can pose a public health risk by contaminating the skin, lungs, and gut of people in nearby communities. These chemicals can lead to respiratory issues, skin irritation, and other adverse health effects. Another study highlights that pesticide poisoning is a significant cause of morbidity and mortality, affecting not just agricultural workers but also the general population.The challenge has been to control this drift without reducing the effectiveness of the pesticide application. This project aims to tackle this pressing issue head-on.
How UC Delivers
Addressing the issue of pesticide drift requires a multi-disciplinary approach, combining engineering, agriculture, and environmental science expertise. The UC Digital Agriculture Program team rose to the challenge by developing an innovative spray backstop system. This system is a blend of practicality and advanced technology, designed to be both farmer-friendly and effective in reducing pesticide drift.
The core components of this system are a foldable mast and a shade structure. The mast is the backbone, providing the necessary height and stability, while the shade structure acts as a barrier covering the trees from the top. This barrier is crucial in preventing the upward movement of pesticide droplets, thereby reducing the potential for drift.
Figure 1: Schematic design of the backstop prototype installed on a sprayer in an almond orchard.
To validate the effectiveness of this system, a series of tests were conducted in young almond orchards. The sprayer was operated at a 3.2 km/h speed to simulate real-world conditions. But before hitting the field, the team employed advanced uncrewed aerial systems equipped with thermal and RGB cameras. These cameras captured images and videos of the spray pattern from multiple angles, providing invaluable data for analysis.
The aerial imagery was not just for show; it played a pivotal role in the project. It allowed the team to monitor the spray application in real-time and understand the spray cloud's movement pattern. This imagery was then used to refine the design of the shade structure, ensuring it effectively blocked droplet movement beyond the treetop.
Figure 2: Aerial views showing the efficiency of the backstop prototype in blocking the spray cloud.
The results were more than just promising. The backstop system effectively blocked the spray cloud, ensuring that the pesticides stayed precisely where they were intended to be—on the trees. This was further validated through a ribbon test, a simple yet effective method to measure drift. A ribbon placed in the spray path remained in its resting position when the backstop system was used, indicating a significant reduction in drift.
The project didn't stop at just reducing drift; it also ensured that the reduction did not come at the cost of effectiveness. The on-target deposition of the pesticide was not compromised, affirming that the system could achieve dual objectives: reducing drift while maintaining efficacy.
The Impact
The spray backstop system's impact goes beyond just numbers. It represents a significant stride toward sustainable agriculture and community well-being. The system successfully reduced the drift potential by 78%. This isn't merely a statistic; it's a tangible change that has far-reaching implications for both environmental stewardship and human safety.
Figure 3: Statistical results showcasing a significant reduction in drift potential.
The environmental impact is equally noteworthy. Reduced drift means fewer chemicals in the air, contributing to "improved air quality," a UC ANR condition change. This is a step forward in reducing air pollution, which has wide-ranging implications for human health and climate change.
One of the most noteworthy aspects of this innovation is that it managed to reduce drift without compromising the effectiveness of the pesticide application. The on-target deposition remained consistent, ensuring the almond trees received the necessary pesticide coverage for optimal growth and yield. This is a crucial factor for farmers who are often caught in the dilemma of choosing between effective pest control and environmental responsibility.
Figure 4: Comparative leaf samples illustrating consistent on-target deposition and coverage.
The project aligns with another UC ANR's condition change, "improved living and working conditions for California's food system and farm workers." One of the goals of reducing pesticide drift is to mitigate the health risks associated with working and living in agricultural production areas. Therefore, the work directly supports UC ANR's commitment to promoting the public health of California's communities.
Looking ahead, the project has set the stage for further research and development to adapt the system for different types of orchards and terrains. Additional modifications are being considered to make the system even more robust and versatile, ensuring its long-term sustainability and broader applicability.
Want to learn more? See the method in action here.
- Author: Peter Ako Larbi
- Author: Franz J.A. Niederholzer
UC ANR supports California's almond crop protection workforce through Airblast Sprayer Calibration Trainings to maintain or improve their technical knowledge. 100% of participants reported both learning professional skills and their intent to adopt practices that can improve the sustainability and profitability of California ag.
The Issue
For efficient and effective pesticide spray application, all sprayers should be calibrated as often as necessary throughout the growing season of almonds, especially when dealing with orchards of different ages and sizes. Calibration is considered a best practice in pesticide spray application ensuring accurate application rates and adherence to pesticide labels which is the law. As such, proper understanding of sprayer calibration objectives and steps is needed to avoid using incorrect methods that give a false sense of accuracy. Educating growers and applicators in calibration methods will therefore empower them to ensure the use of properly calibrated sprayers well-adjusted to the target canopy to deliver maximum crop protection while minimizing pesticide loss.
How UC Delivers
In June 2023, UC ANR co-hosted two Calibration Safety & Compliance Training events, one for Northern California and the other for Central California, with the Almond Board of California (ABC), AgSafe Food and Farms (AgSafe), and the Western Agricultural Processors Association (WAPA). The Northern California training was held at the Nickels Soil Lab in Arbuckle, CA, while the Central California event took place at the UC's Kearney Agricultural Research and Extension (KARE) Center in Parlier, CA. The events were aimed at providing practical calibration training on how to prepare and calibrate airblast sprayers as well as compliance training such as how to manage required documents for pesticide applications. The 4.5-hour trainings included “Welcome” by the ABC, “Regulatory Update” by WAPA, “Calibration Training” by UC ANR, “Headquarters Compliance Training” by AgSafe, and “DPR Laws & Regulations Update” also by AgSafe. The DPR approved 4.0 hours of continuing education credits – 2.0 ‘Laws' and 2.0 ‘Other' – for qualifying participants. Overall, 50+ attendees participated in both events: 30+ in Arbuckle and 23 in Parlier.
The Calibration Training by UC ANR was a 2-hour practical session conducted in an almond orchard along with airblast sprayer demonstrations. It was presented in an interactive format allowing participants to interject with questions, comments, and observations. The Northern California training was led by UC Cooperative Extension advisor Dr. Franz Niederholzer in collaboration with UC Cooperative Extension specialist Dr. Peter Ako Larbi. Alternatively, the Central California training was led by Dr. Larbi in collaboration with Dr. Niederholzer. Both sections covered: “Sprayer parts review”; “Sprayer calibration basics and calculations”; “Sprayer speed determination”; “Sprayer air profile assessment and nozzle configuration”; “Flow rate measurement”; and “Spray coverage evaluation”. Staff from the Nickels Soil Lab, the Agricultural Application Engineering (AgAppE) Lab, and KARE Center provided Logistical, technical, and documentation support. The participants completed evaluation forms to provide feedback for just the Calibration Training section. Comments from the evaluation forms included…
“Very good class.”
“Great rapport with participants.”
The Impact
In all, 22 participants provided feedback on their learning for the combined Calibration Training sections for the Northern and Central California events. Overall, 100% reported “much” to “very much” learning from the combined Calibration Training sections indicating that they were very effective and provided participants with a great amount of learning. Likewise, 100% also indicated their intent to adopt the practices learned from the section. Looking at each section of the training, 82% reported learning “much” to “very much” from the “Sprayer parts review”, 100% the same for “Sprayer calibration basics and calculations”, 91% for “Sprayer speed determination with flagging”, 91% for “Sprayer air profile assessment and nozzle configuration”, 91% for “Flow rate measurement”, and 82% for “Spray coverage evaluation” (full breakdown of feedback by section in the graphic below). Additional written comments were mostly positive.
The needs assessment conducted by Dr. Larbi for his Agricultural Application Engineering Program in 2019 showed that 56% of perennial specialty crop growers and applicators in the San Joaquin Valley used airblast sprayers, 12% used tower sprayers, 15% used electrostatic mist blowers, and 17% used other sprayers. Also, 22% calibrated their sprayers 10 or more times a year, 32% calibrated 4-6 times, and 46% calibrated only 1-3 times a year. According to the California Pesticide Use Report, in 2021, 456,802 pesticide applications delivered 34,323,828 lbs. of pesticide across 24,147,968 acres of almond orchards. This amounts to 75.14 lbs. per application or 1.42 lbs. per acre. If even 1% of the application was overapplied and another 1% was underapplied due to using uncalibrated sprayers in the year (a conservative guess if nearly half of applicators only calibrate 1-3 years times a year), then 686,477 lbs would have been misapplied leading to either reduced pest control or increased pesticide loading on the environment. This number is very significant considering that the situation does not apply to only almond production. Thus, by increasing the competency of California's almond crop protection workforce for properly calibrating sprayers as a best practice, UC ANR potentially improved environmental sustainability.
UCCE academics Dr. Niederholzer and Dr. Larbi have an extended collaboration in providing spray application and sprayer calibration training in both Northern and Central California since 2019. The results presented here exemplify the impact of such trainings. Expanding this collaboration to include industry stakeholders reaches other audiences, potentially new participants, and increases the extent of impact. UC ANR will continue to support California agriculture through such trainings and the dissemination of science-based information to promote operational efficiency and profitability.
- Author: Peter Ako Larbi
UC ANR supports California's crop protection workforce to become more qualified through hands-on Airblast Sprayer Calibration Training. 100% of participants reported learning professional skills that also can improve the sustainability and profitability of California ag.
The Issue
As a best practice in pesticide spray application, growers and pesticide applicators should calibrate their sprayers to ensure accurate application rates and compliance with the law as represented by pesticide labels. However, proper understanding of sprayer calibration objectives and steps is needed to avoid a false sense of accuracy using incorrect methods. Educating growers and applicators in calibration methods will therefore empower them to ensure the use of properly calibrated sprayers well-adjusted to the target canopy to minimize pesticide waste and drift loss.
How UC Delivers
A half-day “Airblast Sprayer Calibration Training” was conducted in November 2022 at the Kearney Agricultural Research and Extension (KARE) Center. The in-person extension education event was supported by a California Department of Pesticide Regulation (DPR) grant. It involved classroom and field exercises focused on axial airblast spray applications directed to tree and vine canopies. The training was instructed by Dr. Peter Ako Larbi and assisted by his postdoc scholar Dr. Abiodun Abioye, with logistical support from his Agricultural Application Engineering (AgAppE) Lab and KARE Center personnel. It covered the basic steps and calculations involved in sprayer calibration, with practical follow up via hands-on demonstrations in the field. The DPR approved 3.5 hours of continuing education credits in ‘Other' category for qualifying participants. Sixteen participants were in attendance consisting of growers, applicators/operators, pest control advisors/certified crop advisors, scientists/researchers, and others.
The training started with classroom instruction covering “Welcome, Introduction, and Purpose” (comprising an overview of spray application goals, spray application outcomes, and sprayer calibration and adjustment objectives) and “Sprayer calibration basics and calculations” by Dr. Larbi. It then transitioned to in-field setting in a citrus block in an interactive format allowing participants to interject with questions, comments, and observations. With active participant involvement, the field experience included a presentation on “Sprayer Equipment Parts/Nozzles” by Dr. Abioye, hands-on exercises covering the calibration steps led by Dr. Larbi, a wrap-up discussion and answering of additional questions, and ended by evaluating participant learning. Engaging participants in various hands-on activities corresponding to the recommended calibration steps was intended to reinforce their learning. The spray equipment was operated by KARE Center staff research associate Ryan Puckett.
“Really helped me understand calibration much better.”
“Excellent speakers, demonstrators, trainers.”
The Impact
The participants were fully engaged throughout the training, and all (100%) provided feedback on their learning. Overall, those who reported gaining “much” to “very much” learning are: 94% for “Welcome, Introduction, and Purpose”; 100% for “Sprayer calibration basics and calculations”; 100% for “Equipment: Sprayer parts/Nozzles”; and 100% for “Hands-on calibration exercise”. On average, 97% reported gaining such learning in the classroom portion and 100% in the field. Overall, 100% reported “much” to “very much” learning from the entire training, indicating that it was very effective and provided participants with a great amount of learning. Additional written comments were mostly positive, and many participants verbally expressed their appreciation for the thoroughness of the training.
Dr. Larbi and his AgAppE Program plan to continue providing similar trainings in the future on both ongoing and need bases to arm his clientele with science-based knowledge and skills that will promote their operational efficiency and profitability.
According to the 2021 California Pesticide Use Report, 82,550,620 lbs. of pesticide was used in 941,751 applications for the top five (5) crops in all counties in the San Joaquin Valley covering 45,087,167 acres. Eighty-nine (89) percent of the quantity was applied on 39,742,883 acres of perennial specialty crops, which are the systems of primary focus for Dr. Larbi and his AgAppE program, amounting to 79.38 lbs. per application or 2.34 lbs per acre. Moreover, Dr. Larbi's 2019 Agricultural Application Engineering Program needs assessment revealed that only 22% of growers and applicators calibrated their sprayers 10 or more times a year, 32% calibrated 4-6 times, and 46% calibrated only 1-3 times a year. Hence, assuming a mere 1% of the application done in perennial specialty crop in 2021 was overapplied and another 1% was underapplied due to using uncalibrated sprayers, then 1,467,100 lbs would have been misapplied leading to either reduced pest control or increased pesticide loading on the environment. This number is very significant considering that the situation does not apply to only the top five crops. Thus, by increasing the competency of California's crop protection workforce for properly calibrating sprayers as a best practice, the AgAppE Program potentially increased workforce retention, improved environmental sustainability, and increased the profitability of growers.
- Author: Peter Ako Larbi
Upon attending the Citrus Spray Field Day in November 2022 at the Kearney Agricultural Research and Extension (KARE) Center, 93% of participants reported learning much or very much about spray application best practices, which can lead to increased agricultural efficiency.
The Issue
Because of the complex nature of spray application under field conditions, growers and pesticide applicators have difficulty in recognizing or using best practices that result in desired application efficiencies. Therefore, applications often fall short. Developing and disseminating science-based recommendations from field trials and decision support tools to assist with pesticide spray application decisions will reduce the guesswork, improve efficiency, and promote effective pest control.
How UC Delivers
The Citrus Spray Field Day was a 4-hour classroom and field meeting that discussed pesticide application effectiveness, focusing on axial airblast spray applications directed to citrus (and other tree and vine) canopies. It was instructed by Dr. Peter Ako Larbi with support from hisAgricultural Application Engineering (AgAppE) Lab andKARE Center personnel. Discussions covered techniques and considerations for optimizing spray deposition and coverage as well as for minimizing pesticide drift. Sixteen participants were in attendance consisting of growers, applicators/operators, pest control advisers/certified crop advisors, regulators/policymakers, scientists/researchers, and others.
Starting with classroom instruction, it covered “Welcome, Introduction, and Purpose” and “Introduction to ‘Airblast Spray Advisor' decision support tool”, transitioning to field instruction which included “Airblast spray demonstration”, “Spray deposition in mandarin” and “Spray deposition in navel orange”. Continuing back in the classroom with sessions on “Spray drift potential in citrus applications” and “Evaluating ‘Airblast Spray Advisor' deposition predictions”, Citrus Spray Field Day ended by evaluating participant learning with approximately 94% response rate.
The Impact
The participants were fully engaged throughout the training. Overall, those who reported gaining “much” to “very much” learning are as follows: 87% for “Welcome, Introduction, and Purpose”; 80% for “Introduction to ‘Airblast Spray Advisor' decision support tool”; 87% for “Airblast spray demonstration”; 93% for “Spray deposition in mandarin”; 94% for “Spray deposition in navel orange”; and 87% in “Spray drift potential in citrus applications”. On average, about 85% reported learning gains in the classroom portion and about 91% reported learning gains in the field. Overall, 93% reported “much” to “very much” learning for the entire field day, showing that the training was very effective and provided participants with a great amount of learning.
Dr. Larbi and his AgAppE Program plan to continue providing similar trainings in the future on both ongoing and need bases to arm his clientele with science-based knowledge that will promote their operational efficiency and profitability.
- Author: Kelly Hong
- Editor: Mishelle Costa
- Editor: Rosa I Vargas
- Editor: Shannon A Klisch
After attending a Teens Love Cooking summer series focused on nutrition and culinary skills, 83% of youth participants were more willing to try new foods and ask for them at home. The class helped reinforce their healthy eating habits and support their long-term health.
The Issue
Collectively, Santa Maria-Bonita and Santa Maria Joint Union High school districts serve over 25,600 students, with more than half of the students qualifying for free or reduced-price school meals. While schools provide nutritious meals for students, teens, in particular, purchase fast food during non-mealtimes such as after school. Fast food meals are heavily targeted towards youth living in low-income neighborhoods and are typically high calorie foods that contain added sugars, saturated fats, and sodium. Furthermore, 52.1% of youth in Santa Barbara County reported eating fast food two or more times a week. Studies have indicated that children and adolescents who learn how to cook at a young age are more likely to adopt healthier eating practices that follow into adulthood. Eating a healthy diet and getting regular exercise can help reduce the risk of diseases related to poor nutrition and weight management such as high blood pressure, heart disease, and stroke.
How UC Delivers
To address this need, CalFresh Healthy Living, University of California Cooperative Extension in Santa Barbara County (UCCE) partnered with Santa Maria Recreation and Parks (SM R&P) to promote a Teens Love Cooking series to middle school and high school-aged youth throughout the city of Santa Maria. Additionally, SM R&P provided access to a full commercial kitchen, kitchenware, and storage space for program materials. With the support of a SM R&P staff member, UCCE staff met with students for two hours, twice a week over three weeks to teach various nutrition and cooking topics, including knife safety, how to follow a recipe, and how to cook a healthy meal using MyPlate as a guide. Additionally, participants put into practice what they learned by preparing recipes from the Cooking for Health Academy curriculum. As needed, recipes were modified to meet COVID-19 safety protocols when cooking in groups using Eat Fresh and Food Hero. Although some recipes needed to be simplified for COVID-19 safety, each participant was provided ample opportunities to practice and grow their food safety and culinary skills. Lastly, every student took home lesson and recipe information to reinforce the learning and to share with their families.
The Impact
At the end of each session, youth were asked to complete the Teacher Tasting Tool, which measures how willing participants are to consume a particular target food again. After tasting a pizza on a whole wheat tortilla, eight (80%) out of 10 respondents reported that they were willing to eat it again. Additionally, after a separate session where participants tasted a fruit salad made with jicama, 15 (83%) of the 18 respondents reported they were both willing to eat it again and ask for it at home.
At the end of the class series, youth completed the “What Did You Learn” open-ended qualitative survey, which asks about changes in knowledge and behaviors. Ten youth responded to the survey, and for the question related to learning, the theme of improved knife skills and safety was reported most frequently, followed by reports related to increased nutrition knowledge, and increased knowledge of healthy food preparation. When asked about one thing that they do differently because of these classes, students responded with the theme of comfortability using a knife and preparing nutritious foods. When teens are confident in their culinary and nutrition skills, they are more likely to make healthier food choices. Overall, participants gained valuable life skills in culinary, food safety, and nutrition to support healthy choices to reduce the risk of diet related diseases which supports ANR's efforts to promote healthy people and communities.
“I really liked the Oatmeal Bites, so I made them at home for my family to taste”. - high school student
