Species Differ in Response to Adjuvants with Glyphosate

Publisher Website
Google Scholar
Abstract
Diammonium sulfate often is used as an adjuvant with glyphosate. Experiments were conducted in the greenhouse to determine the effectiveness of diammonium sulfate in overcoming calcium antagonism of glyphosate toxicity to wheat, sunflower, kochia, and soybean. Each species was a separate experiment and treatments varied with the experiment. Diammonium sulfate at 0.5% (w/v) in a spray carrier containing calcium chloride (500 ppm calcium) overcame calcium antagonism of glyphosate toxicity to wheat, overcame antagonism and enhanced toxicity to sunflower, but only partly overcame calcium antagonism of toxicity to kochia and soybean. With glyphosate at 100 g ae ha–1, diammonium sulfate at 2% (w/v) in a distilled water spray carrier enhanced toxicity to sunflower from a 11% to a 55% fresh weight reduction but was antagonistic to glyphosate toxicity to kochia and soybean.