Pesticide


A pesticide is a chemical used to control, to repel, to attract or to kill
pests, for example, insects, weeds, birds, mammals, fish, or microbes, that
are considered a nuisance. Pesticides are usually, but not always, poisons.

Examples of pesticides

   * herbicides for destruction or development prevention of weeds
   * fungicides for destruction or development prevention of fungi (example,
     QoI)
   * insecticides for destruction or development prevention of insects
   * Growth regulators to prevent excess growth of a plant (prevention of
     lodging in wheat)
   * molluscicides (against snails...)
   * acaricides or miticides against mites
   * products favoring plant resistance...

Chemical engineers continually develop new pesticides to produce
enhancements over previous generations of products.

DDT is an example of a once heavily used pesticide, while glyphosate today
is the world's most used herbicide.

Some crops, such as BT Corn, are genetically engineered to create their own
pesticides.

In the US, all materials intended for sale and use as pesticides must be
registered with the EPA. The process may be long, complex, and expensive,
because research must prove that the material is effective against the
intended pest, yet safe to use. During the registration processs a pesticide
label is created, which has directions for proper use of the material. Use
not consitent with the label is pesticide misuse.

Some pesticides are considered too hazardous for sale to the general public,
and these are designated restricted pesticides. Only certified applicators,
who have taken a course and passed an examination, may purchase and use
restricted pesticides. Records of sales and use are kept, and can be
auditied by the EPA.

"Read and follow label directions." is often quoted by county extension
agents, garden columnists and others teaching about pesticides. This is not
merely good advice; it is the law, for the USA. Similar laws exist in much
of the rest of the world. The Federal Insecticide, Fungicide, and
Rodenticide Act of 1972 (FIFRA) set up the current system of pesticide
regulations. It was amended somewhat by the Food Quality Protection Act of
1996. Its purpose is to make pesticide manufacture, distrubution and use as
safe as possible. The most important point for users to understand is that
it a violaton to apply any pesticide in a manner not in accordance with the
label for that pesticide. It is a crime to so so intentionally.

Most pesticides present some danger to humans when used to control weeds or
insects on food crops. This is one basis for the organic food movement.
Certain food crops such as apples, peppers, celery, cherries, grapes,
nectarines, peaches, pears, potatoes, red raspberries, spinach, and
strawberries contain residual pesticides after being washed or peeled,
although they may still meet government limits which are set to minimize
exposure not eliminate it. These crops are the so-called dirty dozen as
designated by the Environmental Working Group which has issued a Shopper's
Guide to Pesticides in Produce.

Besides human health risks, pesticides also pose dangers to the environment.
Non-target organisms can be severely impacted. In some cases where a pest
insect normally has some controls from a beneficial insect predator or
parasite, an insecticide application can kill both pest and beneficial. The
control insect almost always takes longer to recover than the pest.
Applications for adult mosquitoes, for example, may momentarily depress
mosquito populations, but cause a larger population in the long run, by
damaging controlling factors. Pesticides are also a factor in pollinator
decline, which is a food supply issue.