What is a primary feature of growth-regulator herbicides?

• A. They kill all plants immediately
• B. They selectively target certain plant growth processes
• C. They have no effect on plant growth
• D. They are only synthetic

Answer: (B)

The primary feature of growth-regulator herbicides is that they selectively target certain plant growth processes. These herbicides work by mimicking natural plant hormones, resulting in abnormal growth patterns that affect specific plant species while leaving others unharmed. This selectivity allows for targeted weed management, meaning that beneficial crops can continue to thrive while unwanted plants are inhibited or killed.

Growth-regulator herbicides are designed to interfere with hormonal activity related to growth processes such as cell division, elongation, and overall plant development. This targeted approach makes them effective for managing specific types of weeds within a given environment, allowing farmers and land managers to maintain the health of their desired crops.

The other options refer to characteristics that do not accurately describe growth-regulator herbicides. They do not kill all plants immediately since they act selectively; they do influence plant growth rather than having no effect; and while many are synthetic, the category itself can include naturally derived substances as well.