Biology Reference
In-Depth Information
Part I
Garden Chemicals and Their Application
A fungicide is a substance that destroys or inhibits the growth of fungi. It may
be an eradicant, applied to a plant, plant part, or the environment as a curative
treatment to destroy fungi established within a given area or plant; or prefer-
ably it may be a protectant, applied to protect a plant or plant part from
infection by killing, or inhibiting the development of, fungal spores of
mycelium that may arrive at the infection court. A bactericide is a
substance that destroys or inhibits bacteria and nematicide for nematodes.
Among the more recent bactericides are antibiotics, products of other living
organisms. They also have value against certain fungi. There are few
virocides, which are toxic or poisonous to viruses.
A pesticide is any chemical that is used to kill pests, especially insects
and rodents.
An insecticide is an agent used to kill insects.
A disinfectant is an agent that frees a plant or plant part from infection by
destroying the pathogen established within it. A disinfectant kills or inacti-
vates organisms present on the surface of the plant or plant part or in the
immediate environment. Chemicals for seed treatment can be either
eradicants or protectants, but most of them are disinfestants, in that they kill
organisms on the surface of the seed rather than those within. In common
usage, however, they are called disinfectants.
A nematicide is, of course, a chemical that kills nematodes in the soil or in
the plant. Most nematicides are fumigants, chemical toxicants that act in
volatile form.
Not so long ago the chemicals on the garden medicine shelf consisted
of copper and sulfur for protectants, lime sulfur as an eradicant, mercuric
chloride as a disinfectant, and formalin and carbon bisulfide as
fumigants. You sometimes got plant injury; you did not always get the best
