Definition of terms

3 | 5 | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z


Name Description Related terms
Bacillus thuringiensis (Bt)

Gram-positive bacteria that produce proteinaceous, parasporal, crystalline inclusions during sporulation. Suspensions of the living or dead bacterial cells can be applied as a biopesticide to control larval, leaf-feeding insects. There are different subspecies of Bt that are uniquely active for the control of different orders and species of insect pests.


Microscopically small elemental forms of life that are able to live anywhere and everywhere organic matter can be found (in air, water, soil, bodies of living animals and plants and dead organic matter). They do not require light for growth, but live by attacking and breaking down organic matter—plant or animal. Some bacteria cause disease in plants and animals.

'Bacterium' is the singular form, 'bacteria' is the plural form.

bactericidal activity

The capability of a product to produce a reduction in the number of viable bacterial cells of relevant test organisms under defined conditions.


A chemical that kills vegetative forms of bacteria under defined conditions.


A virus that infects and multiplies within bacteria.


The inhibition of bacterial cell growth and propagation (without killing the bacteria).


for ectoparasiticide dips

An antibacterial agent incorporated into the undiluted product, or added separately to the dip, to minimise bacterial contamination of the dip. Bacteriostats are usually added at the end of each day's dipping. Bacteriostats will not prevent dip infection and are not a substitute for dip hygiene.

bacteriostatic agent

A substance or agent that inhibits bacterial growth and multiplication. Similarly, other static agents inhibit multiplication and growth of other specific groups of microorganisms.


A pesticidal mixture that contains a toxicant (active constituent), a food that the pest prefers and possibly an attractant, eg a pheromone bait.

The formulation type code used by the APVMA for a bait is BA.

bait (ready to use)

A formulation designed to attract and be eaten by a target pest when applied directly from the package without further preparation.

bait concentrate

A solid or liquid intended for dilution before use as a bait, usually designed to be incorporated into material that is a preferred food for the pest.

bait shyness

The tendency for rodents, birds or other pests to avoid a poison bait.

band spray

In relation to the application of a spray, a strip (band) of spray that is applied over a continuous restricted area along a crop row, rather than applied to the whole field as an overall spray.

band spray, band application or band treatment

A spray or granules applied to a continuous restricted area, such as strips on or along a crop row, rather than to the entire field area as an overall spray.

bark spraying

The application of herbicide spray to the bark of woody species.

basal bark treatment

A treatment for killing trees and bushes in which a chemical is applied by sprayer or paintbrush to bark in a band encircling the lower 300 to 600 mm of the stem.

basal treatment

An application to the stems of plants at, or just above, the level of the soil.

baseline data

Information (data) collected after an acclimatisation period in the experimental setting and before the administration of any experimental product to the test animals or plants.

Baseline data for chemical stability studies are the analytical results obtained at the beginning of the study.


The development or maturation of tissues or organs, or the movement of substances (such as hormones), from the apex towards the base of an organism or structure.


The defined quantity of material produced in a single operation or series of operations by a non-continuous process (ie in the same cycle of manufacture), using the same initial starting materials, so that it might be expected to be homogeneous with respect to composition and probability of microbial and/or chemical contamination. The product within a batch will have a uniform quality and character, within specified limits.

batch number

A distinctive combination of letters and/or numbers that specifically identifies a batch during all steps in the manufacture. The production history can be determined from the batch number and its associated records.


A narrow, flat-topped ridge of soil formed for planting crops and located above furrows on each side for drainage.

An area in which seedlings or sprouts are grown for transplanting in the field later.

beneficial insects

Insects that feed on plant pests. Pest management systems should monitor and encourage the presence of these insects as they reduce the reliance on, or need for, chemical insecticides.


Not harmful, not malignant, not recurrent. Favourable for recovery.

benthic region

The bottom region of a body of water. The organisms inhabiting such a region are referred to as benthos.


Aquatic, bottom-dwelling organism communities.


A narrow ledge between the bank of a canal or channel or ditch and the canal itself—may be used as a path or service area.

between-run precision

The within-laboratory, between-run variations of a test or analysis.


A process resulting in a tendency to produce results that differ in a systematic value from the true values.


A plant with a two-year life cycle. It produces leaves and stores food in the first year, produces fruits and seeds in the second year, then dies.

binary variable

A variable that identifies the presence or absence of a trait, characteristic, etc.; 'yes/no' variables.

binary variables
binomial variable

A discrete variable that represents the number of successes out of n (the sample size) identical and independent trials.

binomial variables

The process whereby the amount of a substance becomes concentrated in living organisms with time. The substance may be ingested or taken up by any other means from the environment in which the organisms live.


A quantitative estimation of the potency or concentration of biologically active substances by the extent of their actions, under standardised conditions, on specific living organisms.

Determination of the concentration (dose) of a substance (agent) necessary to obtain a specific response of the test organism. The laboratory determination of the effects of substances or conditions upon specific living organisms.


The rate and extent to which the active constituent or metabolite(s) enters the systemic circulation.


The capability of a substance or mixture of substances to kill living organisms.


Products containing one or more active constituents (or the active constituents themselves) that are supplied to destroy, deter, render harmless, prevent the action of, or otherwise exert a controlling effect on any harmful organism by chemical or biological means.


Capable of being decomposed by the action of microorganisms.


The process whereby microorganisms utilise a substance as a source of energy and bring about its destruction. Usually refers to biological processes in soil, water orsewage,


for agricultural chemical products

Agricultural chemical products are considered bioequivalent if they have the same efficacy and crop safety when applied at the same rate to the same crop under the same conditions.

for veterinary chemical products

The absence of a difference between two products (within predefined acceptance criteria) in the bioavailability of the active constituent or its metabolite(s) of the veterinary chemical products at the site of action when administered at the same molar dose under similar conditions in an appropriately designed study.


An accumulation of microbial cells immobilised on a substratum and embedded in an organic polymer matrix of microbial origin.

biological chemical product

A biological chemical product is one where the active constituent (whether living or not) comprises or is derived from a living or dead organism (plant, animal, virus, microorganism, etc.), with or without modification, but where some essential characteristics of the source material are retained in the product.

biological compound
biological control

A method to control pests using other organisms such as predators, parasites and pathogens, instead of pesticides.

biological index

An index that provides a warning level of biological response to a substance or agent, or warning levels of the substance or agent or its metabolite(s) in tissues, fluids or exhaled air of an exposed worker.

biological monitoring

Measurement of a contaminant or metabolite in a body tissue, fluid, blood, expired air, breast milk and sweat. Biological monitoring is usually used as a marker or indicator of exposure to environmental chemicals.

biological or physiological tolerance

The ability of an organism to withstand unfavourable conditions (such as pest attacks, extreme weather or pesticides) without marked deviation from natural growth or function.

biological oxygen demand (BOD)

The amount of oxygen consumed in biochemical oxidation of the substances contained in the environment.

biological pesticide

From r. 3 of the Agvet Code Regulations (unless the contrary intention appears):

Means an agricultural chemical product containing, or derived from, a living organism, whether or not the organism is genetically modified.

biological product

A product with an active constituent that is a living organism or derived from a living organism.

biologically compatible mixture

A mixture of formulations or chemicals (usually pesticides) that does not have any unwanted biological side effects when used, and of which the components, under defined conditions, retain their separate activities.


Any measurement reflecting an interaction between a biological system and an environmental agent, which may be chemical, physical or biological. Often used to describe measurements used in biological monitoring.


The total mass of living plant and/or animal populations.

biorational pesticide

A pesticide based on bacteria, viruses, fungi or protozoa, including pest control agents, and chemical analogues of naturally occurring biochemicals (pheromones, insect growth regulators, etc.). Biorational pesticides are generally considered safer to humans and the environment.

biorational pesticide and microbial pesticide

The flora and fauna; all living organisms.

biotechnology chemical product

A biotechnology chemical product is one that is developed by means of one of the following biotechnological processes:

  • recombinant DNA technology
  • controlled expression of genes coding for biologically active proteins in prokaryotes and eukaryotes, including transformed mammalian cells
  • hybridoma and monoclonal antibody methods.
biotic insecticide

A pathogen—usually an entomopathogen—that is applied in the same manner as a conventional insecticide to control pest species.


A group of microorganisms that have the same genetic characteristics.


A group of synthetic organic pesticides that contain the herbicides paraquat and diquat.

bird repellent

A pesticide that repels birds or discourages them from roosting or feeding.

Compare with 'avicide'.


An infection of poultry caused by the protozoan parasite Histomonas meleagridis.

blanket application
blanket spray

A pesticide applied as surface spray cover to the entire application site (eg crop, pasture). Compare with more selective band or spot spraying. Typically, boom spraying equipment or aerial spraying is used in commercial broad-acre situations to achieve uniform 'blanket' coverage.


Causing failure to produce fruit or seeds.


A general term used to describe symptoms of plant disease, which may include spotting, sudden wilting and death of leaves, flowers, stems or entire plants.

blind cultivation

Cultivation before the planted crop emerges.


A procedure to reduce potential study bias in which designated study personnel are kept uninformed of the treatment assignments.


From r. 3 of the Agvet Code Regulations (unless the contrary intention appears):

Means a blend or mixture of one or more stockfood ingredients compressed or poured into a solid block form for voluntary consumption by livestock.

block bait

A form of bait that is compressed or moulded.


A readily visible proliferation of phytoplankton, macrophytes or zooplankton in a body of water.

bloom period

The period during which flowers are opened.

blossom stage

From the time the first blossoms open until the petals fall.


A blot or spot, usually superficial or irregular in shape and size, on leaves, shoots and fruit. There is no sharp distinction between leaf blight, leaf blotch and leaf spot.


A section of pipe or tubing that connects several nozzles so that a pesticide can be applied over a wider area.

boom sprayer

Application equipment consisting of a rig of pipes or tubing mounted on a horizontal or vertical boom, with a series of regularly spaced nozzles that can apply pesticide evenly over a target area. Boom sprayers can be self-propelled, or fully trailed tractor- or vehicle-mounted. To reduce the occurrence of spray drift, boom height needs to be adjusted to the minimum practical height, without affecting uniformity of coverage.


The sheath and partially opened blade of the upper leaf in grasses.

boot stage

In cereals (and grasses generally), the boot stage of a growing crop immediately precedes development of the flag leaf, usually a wider leaf and the last leaf to appear before the ear or head starts to emerge. The flag leaf sheath contains the 'boot', a swelling in the sheath, from which the ear will emerge.

botanicals or botanical pesticides

Pesticides made from naturally occurring plant toxins (eg nicotine, pyrethrum, rotenone and strychnine). Also known as plant-derived pesticides.


Of, or pertaining to, cattle


The design of trials (eg stability trials), so that at any time only the samples on the extremes (such as container sizes and dosage strengths) are tested. The design assumes the regularity of the intermediate samples between the extremes.


The husk of wheat or other grain that is separated from flour meal by sieving.

brand name

The manufacturer's name of the product. The name used in product marketing and advertising.


Attaching a brand mark or brand name to a product in order to distinguish it from other product variants.


Members of the Brassica genus of plants in the Brassicaceae (cabbage) family. Members of the genus may also be collectively referred to as cole or crucifer crops. This genus includes many important agricultural and horticultural crops, eg cabbage, cauliflower, brussels sprouts, kale and rape.


A term that refers to the separating of an emulsion into its components or phases. An emulsion may be designed to separate (break) into oil and water phases as soon as it is sprayed on the target. Breaking of an emulsion may occur in the spray tank—this is undesirable because it means a uniform spray cannot be applied.

breeding animal

Any animal that is actively breeding, intended for breeding, or pregnant.


Formation of arches of keyed or jammed particles across the direction of flow of particles of solid material.

British pharmacopoeia

From r. 3 of the Agvet Code Regulations (unless the contrary intention appears):

Means the book of that name published for the British Pharmacopoeia Commission.

British pharmacopoeia (veterinary)

From r. 3 of the Agvet Code Regulations (unless the contrary intention appears):

Means the book of that name published on the recommendation of the Medicines Commission of the United Kingdom.

British pharmacopoeia and British pharmacopoeia (veterinary)
broad-leaf plants

Dicotyledonous plants, including both woody and herbaceous species. Those plants having wide, rounded or flattened leaves and netted veins, as distinct from grasses and grass-like plants. Examples include roses and dandelions.

Compare with 'narrow-leaf plants'.

broad-spectrum herbicide

A chemical that is toxic to a wide variety of plants.

broad-spectrum pesticide

A pesticide that controls or is toxic to a wide range of pests or toxic to more than one plant or animal when applied correctly. A broad-spectrum pesticide does not discriminate between pests and beneficial species, weeds, crops, etc. This type of pesticide may be used when several different pests are a problem. Same as 'non-selective pesticide'.


Distribute evenly over a given area, usually by hand.

broadcast application or treatment

Distribution of an agricultural chemical product uniformly over the entire area to be treated and not just to portions of the area.

broadcast equivalent

For band treatments, the amount of herbicide applied per unit when only the band area is considered. All rates for band treatment should be expressed as the broadcast rate equivalent.

broken emulsion

An emulsion in which there is a visible separation of the originally dispersed oil phase and where there may be visible gradation of emulsified layers or layers at the top or bottom of the emulsion that contain a higher concentration of the active constituent than the other parts of the broken emulsion.

brush control

Control of woody plants such as brambles, sprout clumps, shrubs, trees and vines.


Of, or pertaining to, buffalo.

bud burst or bud opening

A phenological stage leading up to development of the fruit in deciduous fruit trees (ie pre-bud swell, bud swell, bud burst and leaf emergence), where buds begin to show green and young shoots begin to grow from the buds.

bud swell

A phenological stage leading up to development of the fruit in deciduous fruit trees (ie pre-bud swell, bud swell, bud burst and leaf emergence), where buds become engorged and shed their scaled sheaths.

buffer zone

Strip of land of specified minimum width between the edge of an area where pesticide application is permitted and sensitive non-target areas, eg watercourses, wetlands, woodlands, sensitive crops, schools and hospitals.

buffer zone value

Incremental distances (value) determined by APVMA to determine no-spray zones for ground and aerial spray application.


A small bulb. Usually applied to structures produced in the axils of leaves, eg Oxalis incarnata, but also used for small immature offshoots of a root bulb.

bulk density

Mass of the material divided by the volume occupied under stated conditions of free pouring.

bulk product

Any product that has completed all processing stages up to, but not including, final packaging.


A ridge around a chemical storage area in a building or on soil that is used to contain chemical in the event of chemical spillage.


A fungal disease of wheat transmitted on seed or in soil and characterised by the production of masses of fungal spores within the grain.

bypass agitation

Use of returning liquid from a pressure relief valve to agitate a vat or tank of (diluted) product or spray mix. This form of agitation is sufficient to maintain a uniform spray concentration for soluble powders and liquid formulations, eg emulsifiable concentrates and other solutions. Bypass agitation is not appropriate for wettable powders and suspension concentrates, or in large-capacity vats or tanks (eg 200 litres), unless a centrifugal pump is used.

Was this page helpful?

Your feedback will be submitted to the APVMA anonymously. If you require a response, please contact us.