Hooded broadcast sprayer for particle drift reduction.

BACKGROUND: There is renewed interest amongst crop protection professionals and regulators in the adoption of spray hoods to further reduce pesticide off-target movement during applications. Although the benefits of sprayer hoods have been reported since the early 1950s, adoption has been relatively low among farmers and applicators. The objective of this study was to evaluate the effectiveness of spray hoods in reducing pesticide drift of spray solutions from nozzles typically used for herbicide applications in row crops with tolerance to dicamba or 2,4-D. RESULTS: Hooded applications substantially reduced spray drift potential across all treatment scenarios compared to conventional applications. Hooded applications using the AIXR nozzle without drift-reducing adjuvant (DRA) had a similar area under the drift curve (31.5) compared to conventional applications (open sprayer) using the TTI nozzle with DRA (27.7), despite the major droplet size differences between these treatments (DV50  = 447.5 and 985 µm, respectively). CONCLUSION: These results indicate that the adoption of spray hoods combined with proper nozzle selection, and the use of DRAs can substantially reduce spray drift potential during pesticide applications. The use of this technology can be complementary to other drift-reducing technologies. © 2021 Society of Chemical Industry.

Spray particle drift mitigation using field corn (Zea mays L.) as a drift barrier.

BACKGROUND: Herbicide particle drift reduces application efficacy and can cause severe impacts on nearby vegetation depending on the herbicide mode of action, exposure level, and tolerance to the herbicide. A particle drift mitigation effort placing windbreaks or barriers on the field boundaries to reduce off-target movement of spray particles has been utilized in the past. The objective of this research was to evaluate the effectiveness of field corn (Zea mays L.) at different heights as a particle drift barrier. RESULTS: Applications with a non-air inclusion flat fan nozzle (ER11004) resulted in greater particle drift when compared with an air inclusion nozzle (TTI11004). Eight rows of corn were used as barriers (0.91, 1.22, and 1.98 m height) which reduced the particle drift for both nozzles, especially at shorter downwind distances. Applications with the ER11004 nozzle without corn barriers had 1% of the applied rate (D99 ) predicted to deposit at 14.8 m downwind, whereas this distance was reduced (up to 7-fold) when applications were performed with corn barriers. The combination of corn drift barriers and nozzle selection (TTI11004) provided satisfactory particle drift reduction when the D99 estimates were compared with those for applications with the ER11004 nozzle without corn barriers (up to 10-fold difference). CONCLUSION: The corn drift barriers were effective in reducing particle drift from applications with the ER11004 and the TTI11004 nozzles (Fine and Ultra Coarse spray classifications, respectively). The corn drift barrier had appropriate porosity and width as the airborne spray was captured within its canopy instead of deflecting up and over it. © 2018 Society of Chemical Industry.