What is commonly used to ensure deep-water injection nozzles remain positioned near the bottom?

Using weighted hoses is a common practice in ensuring that deep-water injection nozzles are positioned near the bottom. This is because the added weight helps counteract the buoyancy of the hose in the water, which can promote stability and accuracy in positioning. Ensuring that the nozzle stays close to the bottom is crucial for effective pesticide application, as it allows for better targeting of aquatic weeds and minimizes the risk of the treatment being dispersed away from the intended area.

Weighted hoses are designed to sink and remain submerged, reducing the likelihood of movement due to surface currents or other water dynamics. This direct placement near the weed growth zone enhances the overall efficiency of the treatment, leading to more effective control of aquatic species.

In contrast, the other options do not facilitate the same level of controlled positioning near the bottom. Aerosol spray does not apply to this context as it involves dispersing liquid particles into the air rather than delivering a precise dose underwater. Long reach booms, while useful for extending the reach of equipment, do not inherently ensure that nozzles stay near the bottom. High-pressure pumps focus on delivering the pesticide at a certain pressure rather than affecting the positioning of the nozzles themselves.