This list of definitions is of commonly used terms in the agriculture and plant science industry.

BiotechnologyThe use of biological systems, or living organisms, to make or change products. Modern biotechnology (also referred to as gene technology includes the discovery of genes (genomics), understanding gene functions and interactions (functional genomics), use of DNA markers and genetic modification.
Bacillus thuringiensis (also known as Bt)A naturally occurring soil bacterium that produces proteins which are toxic to some insects and nematodes (roundworms). Bt genes have been inserted into some plants, for example cotton, to provide protection from insects. Farmers who produce certified organic crops often use Bt as a spray to provide protection from insects.
ChromosomesOrganised structures of DNA and proteins found in cells.
Conventional (Classical) plant breedingConventional plant breeding produces crops with improved characteristics by changing their genetic makeup.

Conventional breeding achieves it by crossing together plants with relevant characteristics, and selecting the offspring with the desired combination of characteristics, as a result of particular combinations of genes inherited from the two parents.

Breeders use methods and techniques that are based on the mode of reproduction of the species self-pollinating, cross-pollinating, or clonally propagated. Conventional breeding relies largely on homologous recombination between chromosomes to generate genetic diversity. The conventional plant breeder may also make use of a number of in vitro techniques such as protoplast fusion, embryo rescue or mutagenesis (see definition below) to generate diversity and produce hybrid plants that would not exist in nature.

Hybrids may also be produced by a technique called protoplast fusion. In this case protoplasts are fused, usually in an electric field. Viable recombinants (mix of the two 'parent' genes) can be regenerated in culture.
CRISPR-Cas9CRISPR-Cas9 is a modern plant breeding method.

CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats, and Cas for the CRISPR-associated protein. Like a pair of molecular scissors, it can snip precisely at a plant’s DNA enabling plant breeders to turn genes on or off by editing DNA in specific locations.
DNA (deoxyribonucleic acid)Nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses. DNA is usually double-stranded (double helix) with four nucleotides – Adenine, Thymine, Guanine and Cytosine.
DNA marker (also molecular or genetic marker)A known DNA sequence located near a gene of interest. DNA markers are tools that help locate genes of interest in plants and animals.
DNA sequenceThe order of all nucleotides in a stretch of DNA.
FungicidesProtect plants from disease-causing organisms called fungi, like the one that caused the infamous Irish potato famine of the 1800s. In people’s home gardens, roses, tomatoes and peppers are particularly susceptible to fungi. On a farm, a fungus can spread quickly from one plant to destroy an entire field.
Gene technologyThe modern application of biotechnology, including the discovery of genes (genomics), understanding gene functions and interactions (functional genomics), use of DNA markers and genetic modification.
GenesA segment of DNA that carries the instructions for heritable traits.
Gene silencingA method of ‘turning down’ or ‘switching off’ the activity of genes.
Genetic modification (GM)A method of modern plant breeding, genetic modification is altering the genes or DNA of an organism using modern biotechnology techniques.

This includes controlling gene activity, modifying genes and transferring genes in order to investigate gene function. This can be used to generate GMOs or provide information that can be used to speed up conventional breeding.
Genetically modified organism (GMO)An organism that has been altered by genetic modification (a modern plant breeding method).
GenomeThe entire genetic makeup, or all the genes, of an organism.
HerbicidesA pesticide that kills unwanted plants — weeds — so crops can flourish. Weeds and other invasive plants are actually the most damaging pests for many agricultural crops because they compete for vital nutrients, space, water and sunlight.
InsecticidesA pesticide that controls insects that could damage crops by eating them or infecting them with diseases. Fighting these pests is difficult in part because of the wide variety of insects, and because new invasive species are continually being introduced as a result of globalisation. Insecticides protect against insects like locusts, lawn-devouring grubs, tree-smothering caterpillars, maggots that tunnel through fruit crops, and moths/aphids that can devastate grain crops.
Modern plant breedingModern plant breeding may use techniques of molecular biology to select, or in the case of genetic modification, to insert, desirable traits into plants.
Mutagenesis (mutation breeding)A process by which the genetic information of an organism is changed, resulting in a mutation. It may occur spontaneously in nature, or as a result of exposure to mutagens such as radiation, chemical mutagens or transposons (see definition below). Plants bred using mutagenesis are considered conventionally bred and may be used in all forms of farming (conventional and organic).
Organic farmingCrops are grown according to organic standards.

Australia's National Standard for Organic and Bio‐Dynamic Produce is available online. The Standard was implemented for marketing purposes as the Australian Export Standard for products labelled organic or biodynamic.

Australia's organic standards are set and managed by a group of organic standard certifiers, the Organic Industry Standards and Certification Committee (OISCC).

In organic farming, farmers use chemicals (pesticides) approved for use by their chosen organic certifier. The pesticides allowed into an organic production systems are generally derived from plant, animal or mineral resources, with the exception of microbiological processes. There are also exemptions in place for occurrences where organic certifier approved products are not commercially available at the quantities required and where infestations occur that cannot be managed appropriately, and to the potential detriment of yield, using organic certifier approved products. In these instances, synthetically produced chemicals may be used with the approval of the organic certifier and still sold as organic produce.

For a list of Australian Certified Organic approved crop protection products, input, aids and additives see Annex 1, 3 and 4 from page 73 of the Australian Certified Organic Standard 2017
PesticidesAlso known as crop protection products, are used in both conventional and organic farming to keep crops healthy and abundant by protecting them against pests (insecticides), weeds (herbicides) and diseases (fungicides).

Pesticides are also used to control public health disease vectors (like mosquitos) that threaten communities in Australia and around the world.

In conventional farming, farmers use specific chemicals labelled for very specific uses and in specific amounts. In Australia, crop protection products help agricultural industries produce safe, high quality, affordable and abundant food and fibre that is competitive on world markets. They increase Australian crop yields by about 40 per cent as well as increasing the value of our food production by $13 billion each year.

For a list of approved, registered and independently regulated agricultural chemical products allowed to be used in Australia see the APVMA's database.
Plant breedingPlant breeding is the art and science of changing the traits of plants in order to produce desired characteristics.

Plant breeding can be accomplished through many different techniques ranging from simply selecting plants with desirable characteristics for propagation, to methods that make use of knowledge of genetics and chromosomes, to more complex molecular techniques.

Since the practice of agriculture began, eight to ten thousand years ago, farmers have been altering the genetic makeup of the crops they grow. Early farmers selected the best looking plants and seeds and saved them to plant for the next season. Then, once the science of genetics became better understood, plant breeders used what they knew about the genes of a plant to select for specific desirable traits to develop improved varieties.
Transposon (a Transposable Element or TE)A DNA sequence that can change its position within a genome, sometimes creating or reversing mutations and altering the cell's genetic identity and genome size. Transposition often results in duplication of the same genetic material.