Optimizing Adjuvants to Overcome Glyphosate Antagonistic Salts

1993 ◽  
Vol 7 (2) ◽  
pp. 337-342 ◽  
Author(s):  
John D. Nalewaja ◽  
Robert Matysiak

Glyphosate toxicity to wheat was antagonized more by calcium chloride than sodium bicarbonate. Mixtures of the salts at greater than 100 mg L−1sodium bicarbonate and 200 mg L−1calcium chloride were additive in antagonism of glyphosate in the greenhouse experiments. Surfactant and oil adjuvants did not overcome sodium bicarbonate or calcium chloride antagonism of glyphosate. Oil adjuvants were generally antagonistic to glyphosate. An equation is presented that determines the amount of diammonium sulfate required to overcome glyphosate antagonism based upon the sodium, potassium, calcium, and magnesium cations in the spray carrier.

1993 ◽  
Vol 7 (1) ◽  
pp. 154-158 ◽  
Author(s):  
John D. Nalewaja ◽  
Robert Matysiak

Calcium chloride in the spray carrier antagonized the toxicity of diethanolamine 2,4-D and sodium 2,4-D, dimethylamine MCPA, sodium bentazon, dimethylamine dicamba and sodium dicamba, sodium acifluorfen, imazamethabenz, ammonium imazethapyr, and isopropylamine glyphosate to kochia in greenhouse experiments. Diammonium sulfate overcame calcium chloride antagonism of the above herbicides, except for glyphosate and imazethapyr. Diammonium sulfate or ammonium nitrate adjuvants overcame calcium chloride and sodium bicarbonate antagonism of dicamba toxicity to kochia and enhanced toxicity of sodium dicamba to nearly equal that of dimethylamine dicamba.


1991 ◽  
Vol 5 (4) ◽  
pp. 873-880 ◽  
Author(s):  
John D. Nalewaja ◽  
Zenon Woznica ◽  
Robert Matysiak

Research was conducted to determine the influence of salts on 2,4-D toxicity to kochia. Calcium, magnesium, sodium, potassium, and iron salts except for sulfate and phosphate salts of calcium and sodium were antagonistic to 2,4-D diethanolamine. None of the ammonium salts antagonized 2,4-D control of kochia. Effects of individual ions generally antagonistic to 2,4-D were additive when in mixture. 2,4-D generally controlled kochia better when mixed with various acids than with their ammonium salts in distilled, sodium bicarbonate, or ferric sulfate water carriers, relating to the lower pH with the acids. However, low pH was not essential in overcoming salt antagonism of 2,4-D for kochia control, nor was 2,4-D always effective with low pH. Sulfate and monobasic phosphate anions were most effective in overcoming sodium bicarbonate and calcium chloride antagonism of 2,4-D. The concentration of diammonium sulfate needed to overcome sodium bicarbonate antagonism of 2,4-D increased with sodium bicarbonate concentration. Diammonium sulfate at 2% (w/v) overcame 1200 mg L–1sodium as sodium bicarbonate. Nonionic surfactants and oil adjuvants also overcame antagonism of 2,4-D caused by water from several sources.


1992 ◽  
Vol 6 (2) ◽  
pp. 322-327 ◽  
Author(s):  
John D. Nalewaja ◽  
Robert Matysiak

Experiments conducted in the greenhouse indicated that 2,4-D antagonism of glyphosate toxicity to wheat was sodium salt = butoxyethyl ester ≥ diethanolamine. Isopropylamine salt of 2,4-D generally was not antagonistic to glyphosate phytotoxicity. Isopropylamine salt of 2,4-D did not influence the antagonism of glyphosate by inorganic salts in the spray carrier. Antagonism of glyphosate toxicity to wheat by 2,4-D increased when sodium bicarbonate, calcium chloride, and ferric sulfate were in the spray carrier water. Isopropylamine alone as an adjuvant enhanced glyphosate toxicity to wheat, and overcame ferric sulfate and sodium bicarbonate antagonism of glyphosate. Diammonium sulfate adjuvant overcame antagonism to glyphosate phytotoxicity from 2,4-D, sodium bicarbonate, and calcium chloride each alone or the salts in combination with 2,4-D. Nonionic surfactants differed in enhancement of glyphosate but none overcame antagonism from salts or 2,4-D.


Weed Science ◽  
1991 ◽  
Vol 39 (4) ◽  
pp. 622-628 ◽  
Author(s):  
John D. Nalewaja ◽  
Robert Matysiak

Glyphosate is often applied with diammonium sulfate to increase weed control. However, many other salts in the spray carrier have antagonized glyphosate phytotoxicity. Research was conducted with wheat as a bioassay species to further determine the influence of various salts on glyphosate phytotoxicity. Cation antagonism of glyphosate occurred with iron > zinc > calcium ≥ magnesium > sodium > potassium. Ammonium cation with hydroxide or most other anions was not antagonistic. Anions of ammonium compounds were of primary importance in overcoming glyphosate antagonistic salts, while the ammonium cation was neutral or slightly stimulatory with certain anions. Sulfate, phosphate, citrate, and acetate anions were not antagonistic, but nitrate and chloride anions were slightly antagonistic when applied as ammonium salts or acids. Antagonism of glyphosate action by sodium bicarbonate and calcium chloride was overcome by phosphoric, sulfuric, and citric acid and phosphate, sulfate, and citrate ammonium salts. Acid and ammonium salts of nitrate and chloride were more effective in overcoming sodium bicarbonate than calcium chloride antagonists of glyphosate. Ferric sulfate antagonism was overcome only by citric, partly by phosphoric and sulfuric but not by nitric and hydrochloric acids or their ammonium salts. Acetic acid, ammonium acetate, and ammonium hydroxide did not overcome any salt antagonism of glyphosate. Glyphosate response to salts was independent of spray carrier pH.


1993 ◽  
Vol 27 (6) ◽  
pp. 455-462 ◽  
Author(s):  
Anete S. Grumach ◽  
Solange E.I. Jerônimo ◽  
Marcia Hage ◽  
Magda M.S. Carneiro-Sampaio

The composition of breast milk from brazilian mothers delivering low birthweight infants and its adequacy as a source of nutrients for this group has not yet been fully elucidated. A total of 209 milk samples from 66 women were analysed. The mothers were divided into three groups: G1, mothers delivering term babies of low birthweight (TSGA, n=16); G2, mothers delivering preterm babies of appropriate birthweight (PTAGA, n=20); G3, mothers delivering term babies of appropriate birthweight (TAGA, n=30). The following factors were analysed: osmolarity, total proteins and protein fractions, creamatocrit, sodium, potassium, calcium and magnesium. Milk samples were collected 48 h and 7, 15, 30 and 60 days after delivery. The groups did not differ significantly in terms of osmolarity, total proteins and fractions, creamatocrit, calcium, magnesium or potassium throughout the study period. Sodium levels were higher in all samples from mothers of TSGA infants and in samples from mothers of PTAGA infants on the 7th, 15th and 30th days than in milk from the TAGA group. The authors consider the needs of the low birthweight and TAGA infants and that these high sodium levels may be necessary for growth of low birthweight infants.


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