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ARS Home » Southeast Area » Stoneville, Mississippi » Pollinator Health in Southern Crop Ecosystems Research » Research » Publications at this Location » Publication #411270
Research Project: Ecological Assessment and Mitigation Strategies to Reduce the Risks of Bees to Stressors in Southern Crop Ecosystems

Location: Pollinator Health in Southern Crop Ecosystems Research

Title: An algae-based polymer material as a pesticide adjuvant for mitigating off-target drift and protecting pollinator health

Author
item Kannan, Narayanan
item Read, Quentin
item Zhang, Weiqiang

Submitted to: Heliyon
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/30/2024
Publication Date: 8/30/2024
Citation: Kannan, N., Read, Q.D., Zhang, W. 2024. An algae-based polymer material as a pesticide adjuvant for mitigating off-target drift and protecting pollinator health . Heliyon. 10(16):1-18. https://doi.org/10.1016/j.heliyon.2024.e35510.
DOI: https://doi.org/10.1016/j.heliyon.2024.e35510

Interpretive Summary: Off-target pesticide drift from cropland is a major source of pesticide exposure to pollinating insects inhabiting crop and wildlands in the lower Mississippi Delta (LMD) in the USA. The main goal of this study is to develop a drift-reducing pesticide adjuvant that is less/nontoxic to honeybees. Ongoing toxicology experiments with two widely-used insecticides and an algae-based adjuvant (ABA) pointed out reductions in honeybee mortality compared to an industry standard petroleum based adjuvant (PBA). When used as an adjuvant to spray the same insecticides described above, ABA did not interfere in killing the target pests. Therefore, ABA has been tested as a drift-reducing pesticide adjuvant to protect honeybees. Spray experiments in the lab were carried to test both ABA and PBA covering the ranges in spray pressure (three), adjuvant dose (three), and spray nozzles (two). Size and speed of the spray droplets were analyzed using an image analyzer. The drift reduction potential (DRP) of ABA and PBA were compared by (i) dose, (ii) spray pressure, and (iii) nozzle type based on results from lab experiments. Additionally, three field experiments were carried out to analyze the efficiency of ABA in reducing pesticide drift. The results from our field and lab experiments collectively indicate that ABA has significant potential in mitigating drift as well as minimizing pesticide toxicity to honeybees.

Technical Abstract: Off-target pesticide drift from cropland is a major source of pesticide exposure to pollinating insects inhabiting crop and wildlands in the lower Mississippi Delta (LMD) in the USA. This study is aimed to develop a drift-reducing pesticide adjuvant that is less/nontoxic to honeybees. Ongoing toxicology experiments with two widely-used insecticides and sodium alginate (SA) pointed out reductions in honeybee mortality compared to an industry standard reference polyacrylamide (PAM). When used as an adjuvant to spray the same insecticides described above, SA did not interfere in killing the target pests. Therefore, SA has been tested as a drift-reducing pesticide adjuvant to protect honeybees. Spray experiments in the lab were carried out in four sets: (i) water only, (ii) water and adjuvant, (iii) water and pesticide, and (iv) water, pesticide and adjuvant. Each set contained 18 experiments to cover the ranges in spray pressure (three), adjuvant dose (three), and spray nozzles (two). The droplet spectrum was analyzed using a P15 image analyzer. Diameters of 10%, 50% and 90% volumes (DV10, DV50, and DV90), droplet velocity, standard deviation and relative span were measured. The drift reduction potential (DRP) of SA was analyzed by (i) dose, (ii) spray pressure, and (iii) nozzle type. The DRP of SA is compared to that of PAM. Additionally, three field experiments were carried out to analyze the efficiency of SA in reducing pesticide drift. The results from our experiments collectively indicate that SA has significant potential in mitigating drift as well as minimizing pesticide toxicity to honeybees.