Definition - What does Herbicide mean?
A herbicide is a chemical substance used to control or manipulate undesirable vegetation, especially weeds. Herbicides are extensively used in gardening, farming, and landscape turf management.
Herbicides are classified into two categories: selective and non-selective. Selective herbicides kill specific unwanted plants while leaving desirable vegetation relatively unharmed. Non-selective herbicides (total weed killers) kill all or most plant species.
A herbicide can be applied directly to the plant, applied to the soil, or sprayed onto the foliage. Herbicides are applied before, during, or after crop planting in row-crop farming to maximize crop production by diminishing the development of unwanted plants. Herbicides are also applied in ponds and lakes to control aquatic plants, in forests to prepare logged areas for replanting, and to golf courses, lawns, parks, and other areas to clear out unwanted vegetation.
MaximumYield explains Herbicide
Besides selective and non-selective classifications, a herbicide can also be categorized according to three other characteristics:
- Persistence - How long the herbicide remains potent
- Mechanism of action - How it works
- Means of uptake - How the plants will absorb it (e.g., through the roots, aboveground foliage, etc.)
A herbicide’s effectiveness is strongly influenced by its toxic mode of action and the application method. Herbicides can act by inhibiting a plant’s amino acid production, growth, photosynthesis, cell division, or by mimicking natural auxin hormones to cause deformities. Most modern herbicides are synthetic mimics of a natural plant’s hormones that obstruct the target plant’s growth.
Some plants such as the tree of heaven and juglans (walnuts) produce their own natural herbicide. Organic herbicides are useful and are commonly used in organic gardens, but they are less effective and more costly than synthetic herbicides because they based on natural materials.
For difficult cases, a combination of several herbicides is recommended when dealing with herbicide resistance.