Auxin herbicidal mixtures

A herbicidal mixture, comprising:

• an auxin herbicide comprising a first cation and an adjuvant comprising a salt comprising a second cation, wherein the salt is selected from the group consisting of:
• (a) an ammonium salt of Formula I
• wherein R1, R2, R3, and R4 are independently a C1-C12 alkyl or benzyl and X is an agronomically acceptable anion;
• (b) a salt containing a nitrogen heterocycle of Formula II
• wherein A is a 5 or 6-membered heterocyclic ring;
• R5 is a C1-C20 alkyl;
• R6 is hydrogen or a C1-C6 alkyl, and X is an agronomically acceptable anion;
• (c) a phosphonium salt of Formula III
• wherein R7, R8, R9, and R10 are independently a C1-C12 hydrocarbyl and X is an agronomically acceptable anion;
• and mixtures thereof, wherein the herbicidal mixture has a total herbicide concentration no greater than about 40% by weight acid equivalent (a.e.), and wherein the molar ratio of auxin herbicide to adjuvant salt (a), (b), and/or (c) is from about 1:1 to about 3:1.