Interaction between quinclorac and imidazolinones in the control of resistant Cyperus iria to ALS inhibitors

Herbicides belonging to the chemical group imidazolinones and the quinclorac herbicide are important to control weeds in flooded rice. The objective of this research was to evaluate the interaction of imidazolinones with quinclorac to control Cyperus iria resistant to acetolactate synthase inhibitors (ALS). It was conducted two experiments in a greenhouse in a completely randomized design with four replications. Colby’s methodology was used for experiment 1, through the application of quinclorac isolated and in mixture with herbicides imazethapyr, imazapyr e imazapic. The experiment 2, using dose–response curves, tested the herbicides quinclorac isolated and in different mixtures with the herbicide imazethapyr. For experiment 1, the expected and observed averages were compared. For experiment 2, the results were analyzed using the sigmoidal logistic model. Additive is the main interaction of mixtures of quinclorac with different herbicides from the chemical group of imidazolinones to control resistant C. iria . Mixing with imazethapyr at different proportions can cause an additive effect with quinclorac at higher doses.