After attending the Sprayer Calibration training for small scale farmers at the Kearney Agricultural Research and Extension (KARE) Center, 100% of participants reported an increase in learning about spray application best practices, which can lead to an improvement in accuracy and effectiveness of pesticide applications; thus, increasing safety for workers, surrounding communities and consumers.

The Issue

Pesticide resistance is when a pest population becomes less susceptible to a pesticide that was previously effective at controlling the pest. One way this may occur is when a target pest does not receive the full dosage of a pesticide needed to kill it. To prevent pesticide resistance, growers must apply the correct amount of pesticide to kill the pest. Through education, growers can build or refresh their skill and confidence to ensure they are applying the correct amount of pesticide. This could decrease pesticide usage if growers were overapplying as well as prevent the reapplication of pesticides, thus improving the health of communities and consumers.

How UC Delivers

A half-day sprayer calibration training tailored to small-scale farmers was held in December 2024 at the Kearney Agricultural Research and Extension (KARE) Center. Starting with classroom instruction, Marianna Castiaux, a Small Farms Academic Coordinator for Fresno County, covered sprayer calibration basics and maintenance.

Figure 1: Classroom teaching at KARE. Photo Credit Amber Butland.

The training then transitioned to field instruction, which included an all-terrain vehicle (ATV) boom sprayer calibration led by Marianna, followed by a spray drift lecture and demonstration by Dr. Peter Larbi, Assistant Cooperative Extension Specialist in Agricultural Application Engineering at KARE. The demonstration involved simulating wind with a fan, visualizing wind effect using flagging tape, and capturing drifted spray using water sensitive paper to show how far drift from pesticide applications can travel. Lastly, Dr. Singh facilitated a feedback session and conducted a participant needs assessment regarding this new technology, as well as other potential technology needs.

Figure 2: In-field calibration Training by Marianna Castiaux (left) and Dr. Peter Larbi’s drift demonstration (right).

Afterwards, participants saw a demonstration of a new spray technology by Fresno State's David Ryman, Project Engineer, Center for Engineering Innovation and Design (CENID), and Dr. Manpreet Singh, UCCE Technology and Innovation Advisor for Small Farms. The two helped to explain this technology to growers out in the field and also via PowerPoint back in the classroom. Lastly, Dr. Singh gave a feedback session and a needs assessment of participants regarding this new technology, as well as other potential technology needs.

Figure 3: Dr. Manpreet Singh and David Ryman demonstrating the new “see and spray technology”

The Impact

UCCE staff noted that the participants were fully engaged throughout the training. At the end of the training, ten participants provided feedback. Overall, all respondents reported gaining knowledge from the training (Fig. 4) and many wanted more trainings on pesticide safety.

Figure 4: Increase in Knowledge before and after training.

The survey results (Fig. 5) show that for each topic, an increase in learning occurred. Lastly, the feedback session found that growers wanted a simplified handout of recommended nozzles for the top ten pesticides used in small-scale farms, available in different languages and easy to understand. These handouts could be used throughout California, making a wider impact on the larger community and consumers. 

Figure 5: Each question showed an increase in knowledge gained: “How much did you learn about each of the following topics?”