All DSILs evaluated for herbicidal efficacy against common lambsquarters showed similar efficacy compared to parent ILs with a single anion (MCPA or dicamba). These results indicate that there were no noticeable synergistic effects for the analyzed systems comprising large amounts of dicamba anion. Interestingly, the system containing a smaller amount of dicamba (MCPA:dicamba in a molar ratio amounting to 8:2) exhibited the highest biological activity within all the active substances tested and achieved 85% of fresh weight reduction compared to control. It can be concluded that a small addition of dicamba can more than compensate for the loss of MCPA dose. Therefore, the total dose of pesticide can be effectively reduced up to 25%