Safety
34
Glossary of Terms in Pest Control
Active ingredient (a.i.):
The concentration of
chemical in a formulated product responsible for action.
Antagonism:
Opposing action of different chemicals
such that the sum of their total effect is less than the
effect if each pesticide were used alone.
Antidote:
A first aid treatment to offset the toxic effect
of a pesticide.
Bioassay:
Determination of concentration of a pesticide
by comparing its effect on a test organism with that of a
standard preparation.
Adjuvant:
Any substance added to a pesticide
formalation or spray tank to facilitate application.
Chlorotic:
Loss or fading of green colour in foliage.
Contact pesticide:
Causes localized injury to plant
tissue, or causes an effect when the pesticide hits the
pest or the pest contacts the treated surface.
Degradation:
Breakdown of a pesticide by action of
air, water, sunlight, microbes or other agents.
Desiccant:
Chemical use to accelerate drying of
plant tissues.
Efficacy:
Effectiveness of chemical on the pest.
Established forage:
A forage crop that has gone
through three months of a growing season.
Foliar application:
Made to the leaves of plants,
as opposed to soil application.
Formulation:
Form in which the manufacturer
prepares a pesticide to facilitate its use: granular,
solution, emulsifiable concentrate, dry flowable, liquid
flowable, wettable powder.
Fumigant:
Vapour active chemical used against pests.
Incompatibility:
Where one pesticide is mixed with
another causing unsatisfactory results.
Inhibit:
Prevent or stop a process, e.g. inhibits
photosynthesis.
LC
50
:
Lethal concentration – amount of pesticide in air
or water that can kill 50% of the organism.
LD
50
:
Lethal dose – quantity of herbicide that will kill
50%
of a test population.
Mode of action:
The specific mechanism through
which a pesticide affects a pest.
Necrosis:
Localized death of plant tissue, usually
characterized by browning and desiccation.
Non-cropland:
Land not in crop production or not
intended for crop production.
Pesticide group:
A number of pesticides that have
the same mode of action.
Photosynthesis:
Process by which green plants use
sunlight, carbon dioxide and water to produce plant food.
Phytotoxic:
Injurious to a plant.
Plant growth regulators (PGR):
Chemical that
affects the normal growth process of plants.
Preharvest interval (PHI):
Time (days) between
the last application of the pesticide and harvest. Harvest
includes cutting (swathing) or grazing; it does not
include combining or baling for hay.
Residual herbicide:
Persists in soil, kills regrowth
and/or germinating seedlings over an extended time.
Resistance:
A genetic change in a pest population
as a result of selection by a pesticide, which results in a
loss of control.
Synergism:
Complementary action of different
pesticides such that the total effect is greater than the
sum of their independent effects.
Systemic pesticide:
Able to move in the plant, insect
or other organism from the initial point of contact.
Weed control:
A minimum of 80 per cent reduction
in weed stand and/or growth.
Weed suppression:
A minimum of 60 per cent
reduction in weed stand and/or growth.