Which aquatic plant showed resistance reported in 2001?

The reported resistance in aquatic plants in 2001 is associated with Duckweed (Landoltia). This phenomenon illustrates how certain aquatic plants can develop resistance to specific herbicides, which poses challenges for management and control efforts. Duckweed is particularly notable because it's a small, rapidly growing plant that can cover water surfaces, leading to significant ecological and management challenges.

Understanding the mechanisms behind this resistance is crucial for developing effective control strategies. In the case of Duckweed, it has been shown that its ability to adapt to certain herbicide exposures can render control attempts less effective. This adaptability highlights the importance of integrated pest management approaches that consider the ecological implications and resistance potential of various aquatic species.

The other options listed have their own issues regarding management and control, but the specific resistance reported in 2001 pertains to Landoltia, underlining the necessity for ongoing monitoring and research in aquatic weed control practices.