What defines the bottom placement or deep-water injection method?

The bottom placement or deep-water injection method is characterized by the use of hoses with nozzles trailing from a boat. This technique allows for the targeted application of aquatic herbicides directly to the water column or to the sediment at the bottom of a water body. By trailing hoses equipped with nozzles behind a boat, the applicator can achieve controlled dispersal of chemicals in precise locations, minimizing collateral impacts on the surrounding environment and enhancing efficacy against aquatic pests.

In contrast, the other methods described would not specifically facilitate the targeted deep-water application. For example, using mobile tanks for application could imply a more generalized spraying method that does not reach the bottom effectively. Application from a fixed shore point often lacks the depth control needed for successful deep-water treatment, and utilizing only hand-held sprayers is typically associated with shallow applications and less precise targeting in deeper water scenarios.