Are plants more susceptible to herbicides when they are mature?

• A. True
• B. False
• C. Not sure
• D. Sometimes

Answer: (B)

Susceptibility to herbicides is highest when plants are young and actively growing. At that stage, there are many active processes (like cell division and new tissue formation) that herbicides can disrupt, and the chemical can move more readily to growing points. As plants mature, tissues become thicker and tougher, growth slows, and plants often develop stronger barriers and detoxification abilities, which reduce the herbicide’s effectiveness. There are exceptions, but the general pattern is that mature plants are less susceptible. So the statement that plants are more susceptible when mature is not correct.