Spray deposition on plant surfaces: a modelling approach

Area of Science:

• Agricultural Science
• Plant Science
• Environmental Science

Background:

• Effective pest management relies on optimal pesticide deposition on target plant surfaces for active ingredient uptake.
• Understanding spray droplet interception by plants is key to improving pesticide efficacy and minimizing off-target drift.

Purpose of the Study:

• To evaluate a combined plant architectural and particle trajectory model for simulating spray droplet deposition.
• To compare simulated glyphosate deposition with experimental wind tunnel data across different plant species and growth stages.

Main Methods:

• Utilized a 3-D plant architectural model integrated with a particle trajectory model to simulate spray interception.
• Conducted wind tunnel experiments to measure glyphosate deposition on cotton, sow thistle, and wild oats using specific spray nozzles.
• Compared simulation predictions against experimental data for model validation.

Main Results:

• The model accurately predicted glyphosate deposition, with minor overprediction on sow thistle.
• An extended range flat fan nozzle showed higher deposition on wild oats compared to an air induction flat fan nozzle.
• Spray deposition per unit area was significantly higher on 5-leaf stage wild oat plants than on 2-leaf stage plants or sow thistle.

Conclusions:

• The integrated modeling approach provides a reliable tool for predicting pesticide spray deposition patterns.
• Plant architecture and growth stage are critical factors influencing spray deposition efficiency.
• Nozzle selection and operating pressure can be optimized based on target species and crop stage for improved pesticide application.