Veteran Advisor
Posts: 1,559
Registered: ‎10-18-2016

Re: Herbicide Antagonism

A search online showed this for starters.  (This is a complicated subject.)


Herbicides can interact physically or chemically in the tank mix.or biologically in the plant.  There can be effects even if one sprays them one after the other (not in the same tank mix).


Antagonism is more common than synergism.


Mixing a grass herbicide with a broadleaf herbicide tends to reduce the effectiveness of the grass herbicide.


Among the ways there can be antagonism in the plant are that one herbicide does not reach the site of action at full strength, that it is blocked from binding at the site of action, the two chemicals cancel each other or even that they have the opposite of intended effect.


I wish there was more current research on this.