Agriculture Reference
In-Depth Information
from insects or to introduce a systemic to roots for transport to above-ground
parts in lawns and ornamentals.
13. Poisonous Baits
A poisonous bait is a pesticide mixed with an edible material that is at-
tractive to a particular pest. The pests are killed by consuming a lethal dosage
of the poison either in a single feeding or over a period of time. Baits are
sometimes used to control rodents. Although you may not need to cover the
whole area, the bait must be placed where it is likely to be consumed.
The percentage of active ingredient in bait formulations is quite low, usu-
ally less than 5%; in addit ion, only small amoun ts of pesti cide are used in
relat ion to the effective area of treatment. Because the "method of application"
also limit s the amoun t of pesti cide intro duced into the envir onment, envi-
ronmental contamination can be minimized. Baits may, however, be attractive
to non-target organisms. If a bait is not adequately selective, extra caution
should be used to prevent non-target organisms from reaching it, either by
placing it properly or by using screens, boxes, or other types of physical
barri ers.
14. Fumigants
Fumigants are a rather loosely defined group of formulations. They are a
substance or mixture of substances which produce gas, vapor, fume, or smoke
intended to destroy insects, bacteria, or rodents. Fumigants may be volatile
liquids and solids as well as gases. They are used to disinfest the interiors of
buildings, objects and materials that can be enclosed so as to retain the fumi-
gant. Soil fumigants are also used in horticultural nurseries, greenhouses, and
on high-value cropland, such as tobacco, to control nematodes, insect larvae
and adults, and sometimes to control diseases and weed seeds. Depending on
the fumigant, the treated soils may require covering with plastic sheets for
several days to retain the volatile chemical, allowing it to exert its maximum
effect.
15. Adjuvants (Additives)
An adjuvant or additive is a chemical added to a pesticide to increase its ef-
fectiveness or to reduce its phytotoxicity or drift. Adjuvants are used most
extensively in products designed for foliar applications. Most pesticide formu-
lations already contain adjuvants. Several different types of adjuvants are:
Wetting agents
and
emulsifiers
are often added so that the pesticide will
mix with water and/or coat treated surfaces more effectively.
