Quinclorac - Not Always an Auxin Mimic

Interestingly, quinclorac does not act like an auxin in grass species that are sensitive, like corn or barnyardgrass. Although quinclorac does act like an auxin in broadleaf species, there is strong evidence that quinclorac is capable of rapidly inhibiting cell wall synthesis in sensitive grasses (Figure 16), leading to plant death.

Fig. 16 Quinclorac inhibition of cell wall synthesis in corn roots. Photo from Joseph C. Neal, NCSU.