Mode of Action
Three main groups of agrichemicals are used in horticulture: insecticides, fungicides, and herbicides. Agriculture primarily uses herbicides, animal remedies and, in the dairy sector, dairy detergents.
Agrichemicals in each group are further categorised according to their mode of action - how they kill or disrupt their target.
Insecticides
Mode of action |
How it works |
Examples |
Systemic |
Moves within plant sap, eaten by sucking insects |
Attack, Counter 20G, Rogor E |
Contact |
Picked up when insects are hit directly by spray droplets or move across treated plant surfaces |
Azinphos methly, Lannate L |
Stomach poison |
Must be eaten by the insect |
Azinphos methyl, Foray, 48B |
Nerve poison |
Affects the insect's nervous system |
Lorsban, Rogor E, Folidol M50, Tamaron |
Fumigant |
Active in the vapour phase |
Attack, Thimet 20G, Pirimor 50 |
Fungicides
Mode of action |
How it works |
Examples |
Protectant |
Contact acting chemicals that prevent new infections by killing fungal spores |
Combo, Baycor, Kocide, Rovral |
Partially systemic or translaminar |
Usually exhibit protectant activity plus suppression or control of established disease within plant tissue |
Combo, Acrobat MZ 690, Twist |
Fully systemic |
Move freely in plant vascular system, exhibit curative activity against established disease |
Bayleton, Speartek, Ridomil |
Curative or eradicant |
Kill out established diseases |
Rizolex, Tilt EC, Topas |
Herbicides
Mode of action |
How it works |
Examples |
Desiccants or knockdowns (contact) |
Rapid response to burn off green parts of plants |
Reglone, Preeglone |
Translocated or systemic |
Absorbed into the plant and moves to active area |
Amitrole, Answer, Glyphospate |
Hormone-type (translocated) |
Mimic plant growth regulators, often translocated. Phenoxy-herbicides are the main group |
2,4-D, MCPA, MCPB |
Pre-emergent |
Applied to seed bed before planting or crop emergence |
Treflan NF |
Animal Remedies
Animal remedies are usually categorised by the way in which they are applied to the animal.
Mode of action |
How it works |
Examples |
Pour-on |
Drench applied to the skin of animal |
Cydectin, Bomectin, ProAbamec |
Oral drench |
Drench given via the mouth using a drench gun |
Alliance, Converge, SCANDA Selenised |
Injection |
Administered into the neck of the animal via a needle and syringe |
Cydectin, Closamectin, Noromectin |
Intramammary |
Tube containing antibiotic that is inserted into one of the cow's teat canals |
Bovaclox Dry Cow, Cobactan lC, Penalone |
Controlled release drug |
Capsule delivered down the animal's throat via an applicator |
Rumetrace,Magnesium Capsules, Rumensin |
Dairy Detergents
Milking plant and vat cleaning routines involve the use of acid and alkaline solutions,
Mode of action |
How it works |
Examples |
Acid detergent |
Removes mineral deposits |
|
Acid sanitisers |
Chemicals such as chlorine, iodine or cationics kill bacteria |
Quantum, Optimum |
Alklaine (base) detergents |
Remove fat and protein |
Rapid, Protosol, Quantum |