Which statement best describes selectivity in herbicides?

• A. It means the herbicide kills all plants in the area.
• B. It ensures crops are immune to all pests.
• C. It targets only certain plant types while sparing others.
• D. It requires sunlight to be activated.

Answer: (C)

Selectivity in herbicides means the chemical can control certain plant types while leaving the crop relatively unharmed. This happens because crops and weeds differ in how they take up, metabolize, or respond to the herbicide’s site of action. Some crops tolerate the chemical due to protective mechanisms or rapid detoxification, while the targeted weeds are sensitive and are killed or suppressed. For example, a herbicide that disrupts a growth pathway may kill broadleaf weeds but not grasses, allowing a cereal crop to survive. It’s not about killing all plants, nor about crops being immune to all pests, and it doesn’t require sunlight to activate.