Chemical Herbicides

The realm of agriculture, before being introduced to herbicides, initially underwent a rather practical procedure in protecting plants. This was done by controlling the weeds by changing the soil pH, fertility and salinity levels. While tilling the soil is still also used as an alternative to prevent the weeds from spreading.

Chemical Herbicides

However, these days, for the most part, a farmer is inclined to use herbicides, chemicals used to remove weeds that affect the growth and health of crops. This chemical, in the same manner, is applied to plants to further protect them from damage.

Some common herbicides that have been widely used are 2,4-dichlorohenoxyacetic acid or 2,4-D, which is inexpensive and easy to use. But this has poor selectivity wherein it may also cause damage to other plants. Meanwhile, Atrazine is another type of herbicide, which was discontinued since it contaminates groundwater.

Herbicides can be divided into different classifications. According to activity, herbicides can be either contact herbicides that destroy the plant tissue upon contact and systemic herbicide which are absorbed into the plant, leading to its destruction. By use, they are classified as soil applied, pre-emergent which is applied before the crop comes out and post emergent, added after the crop comes out. By the mechanism of action, they may be Acetyl coenzyme carboxylase inhibitor, compounds that kill grasses, acetolactate synthase enzyme that inhibit DNA synthesis, EPSPS inhibitors which act on the synthesis of amino acids tryptophan, phenylalanine, and tyrosine, synthetic auxin, an organic herbicide, and photosystem II inhibitors, which use excessive oxidation reactions to cause plant death. Moreover, other herbicides are classified according to their mode of action or the type of plants they control.

Like with pesticides, the uses of herbicides affect a person's health. Even if you don't get into direct contact with it, ingesting food treated with herbicides is potentially dangerous, especially genetically altered food since they are subject to more herbicides when they are altered to be resistent to the herbicidet.

Organic Herbicides

However, there are also herbicides that can be considered as organic. These herbicides are specifically designed for the use of an organic farm. As such, it is more expensive and is sometimes less effective than synthetic herbicides but it causes little to no damage to the environment. An example of an organic herbicide is one made of spices, 20% solution of acetic acid or vinegar, which is effective for destroying surface growth. Steam is considered a herbicide but has been discontinued since it is inadequate and expensive. Fire is also used as a herbicide which is better than steam but is also inadequate and expensive.