Mitigating Necrosis in Transgenic Glyphosate-Tolerant Cotton Plants Treated with Herbicidal Glyphosate Formulations

Abstract

This invention relates generally to improved methods and herbicidal glyphosate compositions for use in controlling the growth of weeds and unwanted vegetation, and particularly for use in controlling weeds in a crop of transgenic glyphosate-tolerant cotton plants by over-the-top, foliar application of a herbicidal glyphosate formulation.

What is claimed is: 
     
         1 . A herbicidal glyphosate composition in the form of an aqueous concentrate, comprising:
 N-(phosphonomethyl)glycine predominantly present in the form of the potassium salt, the concentration of said N-(phosphonomethyl)glycine being at least about 500 grams per liter on an acid equivalent basis;   N-(phosphonomethyl)iminiodiacetic acid or a salt thereof;   a safening agent comprising polyvalent iron ions;   a solubilizing ligand comprising citric acid; and   a surfactant component comprising an etheramine of formula (4):   
       
         
           
           
               
               
           
         
       
       wherein R 1  is a straight or branched chain C 6  to about C 22  alkyl, aryl or arylalkyl group, m is an average number from 1 to about 10, R 2  in each of the m (O—R 2 ) groups is independently C 1 -C 4  alkylene, R 3  groups are independently C 1 -C 4  alkylene, and x and y are average numbers such that x+y is in the range from 2 to about 60; and
 an ethoxylated alkylamine of formula (3): 
 
       
         
           
           
               
               
           
         
       
       wherein m+n is between about 2 and about 25 and R is a branched or straight chain alkyl group having from about 12 to about 22 carbon atoms;
 wherein the solubilizing ligand is present in the composition in molar excess relative to the polyvalent iron ions and the molar ratio of polyvalent iron ions to N-(phosphonomethyl)iminodiacetic acid equivalent is at least about 0.4:1. 
 
     
     
         2 . The composition of  claim 1  wherein the safening agent is derived from a compound selected from the group consisting of ferric sulfate, ferric chloride, iron salts of di-, tri-, and other polycarboxylic acids and mixtures thereof. 
     
     
         3 . The composition of  claim 1  wherein the molar ratio of polyvalent iron ions to N-(phosphonomethyl)iminodiacetic acid equivalent is no greater than about 25:1. 
     
     
         4 . The composition of  claim 1  wherein the molar ratio of polyvalent iron ions to N-(phosphonomethyl)iminodiacetic acid equivalent is from about 0.5:1 to about 25:1. 
     
     
         5 . The composition of  claim 1  wherein the safening agent is derived from ferric sulfate and the solubilizing ligand comprises citric acid. 
     
     
         6 . The composition of  claim 1  wherein the solubilizing ligand is present in the composition in molar excess relative to the polyvalent iron ion. 
     
     
         7 . The composition of  claim 6  wherein the molar ratio of solubilizing ligand to polyvalent iron ion is from about 1.5:1 to about 4:1. 
     
     
         8 . The composition of  claim 1  wherein R 1  is a straight or branched chain C 6  to about C 22  alkyl group. 
     
     
         9 . The composition of  claim 1  wherein R 2  is ethyl or propyl and R 3  is ethyl or propyl. 
     
     
         10 . The composition of  claim 1  wherein x+y is 5. 
     
     
         11 . The composition of  claim 1  wherein R in formula (3) is coco or tallow. 
     
     
         12 . The composition of  claim 1  wherein R in formula (3) is coco. 
     
     
         13 . The composition of  claim 1  wherein the concentration of N-(phosphonomethyl)glycine or an agronomically acceptable salt thereof is from about 500 to about 600 grams per liter on an acid equivalent basis. 
     
     
         14 . The composition of  claim 1  wherein the concentration of N-(phosphonomethyl)glycine or an agronomically acceptable salt thereof is at least about 520 grams per liter on an acid equivalent basis. 
     
     
         15 . The composition of  claim 1  wherein the concentration of N-(phosphonomethyl)glycine or an agronomically acceptable salt thereof is at least about 540 grams per liter on an acid equivalent basis. 
     
     
         16 . The composition of  claim 1  wherein the concentration of N-(phosphonomethyl)glycine or an agronomically acceptable salt thereof is at least about 560 grams per liter on an acid equivalent basis. 
     
     
         17 . The composition of  claim 1  wherein the amount of N-(phosphonomethyl)iminodiacetic acid or salt thereof is less than 5 grams per liter of the composition on an acid equivalent basis.