Agriculture Reference
In-Depth Information
although compounds containing lead, mercury, and arsenic have generated
widespread health and environmental concerns and their use has been either
banned or severely curtailed.
2.
Organic Pesticides
The organic pesticides contain carbon. They also contain hydrogen and of-
ten oxygen, nitrogen, phosphorus, sulfur, or other elements. Most pesticides
used today are organic compounds. A few organic pesticides are either derived
or extracted directly from plants. Most, however, are synthetic compounds. It
is these compounds that have been responsible for the expanded use of pesti-
cides since World War II. They are often extremely effective and easy to use,
have been relatively lowcost and some are quite specific in their activity.
They have, however, been the principal focus of health and environmental
concerns and are the pesticides most commonly associated with problems of
pesticide use and misuse.
Figure 5.5
Assorted products containing various organic pesticides.
3.
Biological Pesticides
A distinct group of pest control agents are the so-called microbial pesti-
cides. These are bacteria, viruses, and fungi which cause disease in given spe-
cies of pests. Although they occur naturally in certain areas, they are some-
times intentionally introduced in sufficient quantities that a relatively high
level of control becomes possible. They tend to be highly specific in their
activity and are often virtually harmless to non-target species. There are,
