Which type of herbicide is amply illustrated by paraquat and diquat?

Paraquat and diquat are classified as photosystem I inhibitors. This means they interfere with the photosynthesis process in plants specifically by targeting the photosystem I complex, leading to the generation of reactive oxygen species that ultimately damage plant cells. This mechanism causes rapid desiccation and death of the plant tissues.

Photosystem I inhibitors are distinct in their action compared to photosystem II inhibitors, which target a different complex in the photosynthetic pathway and have different effects on plants. Growth stimulants and soil sterilants do not share the same mechanism of action as paraquat and diquat. Growth stimulants promote plant growth and development, while soil sterilants aim to eliminate all plant life in the soil. In contrast, photosystem I inhibitors specifically target the photosynthetic machinery of plants, making them effective as contact herbicides.