Low volatility auxin herbicide formulations

Abstract

Low volatility dicamba herbicide formulations are described. In some embodiments, concentrate formulations comprising dicamba monoethanolamine salt, dicamba potassium salt, or mixed dicamba salts are provided. In other embodiments, a dicamba salt is combined with a polybasic polymer.

What is claimed is: 
     
         1 . An aqueous herbicidal solution concentrate formulation useful for killing or controlling the growth of unwanted plants, the formulation comprising an auxin herbicide salt and a pH buffer. 
     
     
         2 . The formulation of  claim 1  wherein the pH buffer comprises a polybasic polymer. 
     
     
         3 . The formulation of  claim 1  wherein the auxin herbicide salt is selected from the group consisting of the monethanolamine salt, sodium salt, potassium salt, diethanolamine salt, isopropylamine salt, diglycolamine salt, dimethylamine salt, and combinations thereof. 
     
     
         4 . The formulation of  claim 1  wherein the pH is from about 4 to about 11. 
     
     
         5 . The formulation of  claim 1  wherein the pH is from about 5 to about 10. 
     
     
         6 . The formulation of  claim 1  wherein the pH is from about 7 to about 9. 
     
     
         7 . The formulation of  claim 1  comprising at least 50, 100, 150, 200, 250, 300, 350, 400, 450, 480, 500, 520, 540, 560, 580, 600, 620, 640, 660, 680 or 700 grams acid equivalent per liter of dicamba salt. 
     
     
         8 . The formulation  claim 7  further comprising at least one surfactant wherein the weight ratio of dicamba salt acid equivalent to surfactant is from 1:1 to 20:1. 
     
     
         9 . The formulation of  claim 8  wherein the surfactant is selected from alkoxylated tertiary etheramines, alkoxylated quaternary etheramines, alkoxylated etheramine oxides, alkoxylated tertiary amines, alkoxylated quaternary amines, alkoxylated polyamines, sulfates, sulfonates, phosphate esters, alkyl polysaccharides, alkoxylated alcohols, and combinations thereof. 
     
     
         10 . The formulation of  claim 1  further comprising at least one co-herbicide. 
     
     
         11 . The formulation of  claim 10  wherein the co-herbicide is selected from the group consisting of acetyl CoA carboxylase (ACCase) inhibitors, acetolactate synthase (ALS) or acetohydroxy acid synthase (AHAS) inhibitors, photosystem II inhibitors, photosystem I inhibitors, protoporphyrinogen oxidase (PPO or Protox) inhibitors, carotenoid biosynthesis inhibitors, enolpyruvyl shikimate-3-phosphate (EPSP) synthase inhibitor, glutamine synthetase inhibitor, dihydropteroate synthetase inhibitor, mitosis inhibitors, synthetic auxins, auxin transport inhibitors, nucleic acid inhibitors, and salts and esters thereof; racemic mixtures and resolved isomers thereof; and combinations thereof. 
     
     
         12 . The formulation of  claim 11  wherein the co-herbicide is selected from the group consisting of acetochlor, acifluorfen, alachlor, atrazine, azafenidin, bifenox, butachlor, butafenacil, carfentrazone-ethyl, diuron, dithiopyr, flufenpyr-ethyl, flumiclorac-pentyl, flumioxazin, fluoroglycofen, fluthiacet-methyl, fomesafen, glyphosate, glufosinate, imazethapyr, lactofen, metazochlor, metolachlor (and S-metolachlor), oxadiargyl, oxadiazon, oxyfluorfen, pretilachlor, propachlor, propisochlor, pyraflufen-ethyl, sulfentrazone and thenylchlor, and salts and esters thereof; racemic mixtures and resolved isomers thereof, and combinations thereof. 
     
     
         13 . A method of using dicamba herbicide to control auxin-susceptible plants growing in and/or adjacent to a field of crop plants, the method comprising the steps of (i) preparing an aqueous herbicidal application mixture by diluting with water an aqueous herbicidal solution concentrate formulation comprising a dicamba salt and a pH buffer, and (ii) applying the aqueous herbicidal application mixture to the foliage of the auxin-susceptible plants.