What type of nozzle is typically used for subsurface injections?

The correct choice pertains to the nozzle that is designed with a disk regulating water flow. This type of nozzle is ideal for subsurface injections because it allows for a controlled delivery of the pesticide directly into the target area beneath the water's surface. The disk helps manage the flow rate and pressure, ensuring that the product is injected effectively without creating excessive turbulence that could disperse the chemical beyond the intended area.

Optimal subsurface injection relies on both the accurate placement of the pesticide and the correct flow regulation to minimize potential non-target impact and enhance efficacy. A nozzle that creates foam, for instance, would not be suitable as it could lead to surface contamination and dispersion rather than targeted delivery. Similarly, high-pressure nozzles that produce a fine mist may not provide the necessary depth or precision for effective subsurface application, risking loss of the chemical from the intended area. Lastly, while a flexible nozzle might allow for variations in depth, it does not inherently ensure the precise flow regulation needed for safe and effective subsurface injections. Thus, using a nozzle with a disk to regulate water flow stands out as the most efficient and controlled method for such applications.