Final answer:
Herbicides are classified as synthetic or organic based on their composition and usage in farming. Synthetic herbicides like 2,4-D are man-made and effective, while organic herbicides such as corn gluten meal are natural and used in organic farming.
Step-by-step explanation:
The classification of herbicides into synthetic or organic largely depends on their composition and use in farming practices. Commonly used synthetic herbicides, such as 2,4-D (2,4-dichlorophenoxyacetic acid) and glyphosate, are man-made chemicals designed to interfere with the growth process of target plants.
On the other hand, organic herbicides include substances like corn gluten meal, vinegar, and D-limonene, which are used in organic farming and are derived from natural materials. While synthetic herbicides are often more effective, organic herbicides are favored in organic farming due to their environmental friendliness, though they may require more frequent application.