Texas FFA Nursery Landscape Practice Exam

What type of herbicide is applied after the weeds have emerged from the soil?

1. Pre-emergent

2. Post-emergent

3. Selective

4. Non-selective

The correct answer is: Post-emergent

The correct choice focuses on herbicides designed to be applied after weeds have already emerged from the soil, making them effective in managing existing weed populations. Post-emergent herbicides work by targeting the actively growing weeds, allowing for the application once they are visible and can be effectively controlled. This type of herbicide can be selective, targeting specific weed species without harming desirable plants, or non-selective, affecting all plant life in the treated area. Pre-emergent herbicides, unlike post-emergents, are intended for application before weed seeds germinate and rely on the prevention of new weed growth rather than removing existing plants. Thus, they do not apply to the scenario where weeds are already present. Selective herbicides focus on eradicating certain types of weeds while sparing desired plants, but the core characteristic of post-emergent herbicides is their timing of application after weed emergence. Non-selective herbicides are not focused on timing relative to weed emergence but are instead broad-spectrum products that kill a wide variety of plants. While they can also be applied after weeds emerge, it’s the post-emergent classification that specifically refers to their application at that stage of growth. Overall, post-emergent herbicides are specifically formulated for