What is the purpose of the disk contained within the nozzle body for subsurface injection?

The purpose of the disk contained within the nozzle body for subsurface injection is to meter flow into water. This component is designed to regulate the amount of herbicide that is injected into the water system, ensuring a consistent and controlled application. Proper flow metering is crucial for effective herbicide delivery, as it helps in maintaining the desired concentration and coverage needed for weed control while minimizing waste and environmental impact.

This specific function of flow metering allows for precision in herbicide application, which is essential in managing aquatic weeds efficiently. Ensuring that the right amount of herbicide reaches the target area can enhance the effectiveness of the treatment and reduce the risk of over-application, which could lead to unintended consequences in the aquatic ecosystem.

In contrast, filtering the herbicide would focus on removing impurities before application, increasing pressure would affect the force of the application rather than the flow rate, and decreasing droplet size pertains to the physical characteristics of the spray rather than the flow metering process involved in subsurface injection.