There are a couple of other MoAs that are specific to herbicides:
Selective – contact herbicide that interrupts the production and effect of auxin (the PGR that controls growth) in broad leaved (dicotyledon) weeds. The weeds die but grasses are unaffected so these herbicides are used on lawns.
Residual – these remain active in the soil after application and either kill newly germinated seeds and seedlings or create a barrier preventing their emergence from the soil.
Exercise – answers diquat dibromide contact 5. herbicide Flufenacet / metosulam (both residual) glyphosate (contact) residual/contact 4. herbicide triticonazole systemic 3. fungicide glyphosate systemic 2. herbicide thiacloprid systemic 1. pesticide Active ingredient Mode of action Type of chemical
Allows plants to be precisely identified – not lumped together by a single characteristic.
Same common names are often used for unrelated plants.
No language barrier – Latin is the botanical naming convention all over the world.
Gives information about the plant and about its inheritance and possibilities for cross breeding etc.
Group exercise answers In each case control could also be achieved in ground that was not intended to bear vegetation with a residual weed killer. Diquat (contact) Chenopodium album Fat Hen Diquat (contact) Cardamine hirsuta Hairy Bitter Cress Diquat (contact) Senecio vulgaris Groundsel Diquat (contact) Stellaria media Chickweed Diquat (contact) Gallium aparine Cleavers Chemical Control Botanical name Common name