Herbicidal ionic liquids containing double or triple anions as a new potential tool for weed control including herbicide-resistant biotypes

Herbicides are commonly used in modern agriculture for the control of unwanted plants. Contemporary expectations regarding agrochemicals emphasize the need to ensure high effectiveness and reduce side effects. Multicomponent herbicidal ionic liquids possess these features. In planning the syntheses of herbicidal ionic liquids (HILs), we took into account ensuring high activity against weeds using reduced doses of active substances and the problem of controlling herbicide-resistant weeds.
Eight new double-anion and eight new triple-anion HILs were synthesized. All obtained HILs contained methyl dodecylbetainate cation and herbicidal anions belonging to both sulfonylurea and auxin-like groups of active substances in a single compound. The new HILs were tested under greenhouse and field conditions and they showed excellent efficacy against target dicotyledonous weeds. Some compounds showed very good surface properties, which are desirable for foliar application to plants. Moreover, HILs with three herbicidal anions (iodosulfuron or metsulfuron + 2,4-D + clopyralid) were very effective against cornflower biotype resistant to acetolactate synthase inhibitors.
Our research indicate that herbicidal ionic liquids containing a cation of natural origin and herbicidal anions characterized by a different mode of action in a single compound are a potential new tool for weed management. The use of multicomponent herbicidal ionic liquids enables effective weed control with lower doses of the active ingredient.