Enhanced method of killing weeds with glyphosate herbicide

摘要

A method of enhancing herbicidal activity of a glyphosate herbicide comprises adding to the glyphosate herbicide a mixture of a first surfactant and a second surfactant at a weight ration of a total surfactant to a glyphosate acid equivalent of about 1:30 to about 1:2. The first surfactant has a structure comprising a cationic or protonatable amino group and a C8-24 hydrocarbyl group. The second surfactant has the formula R-CO-NR'-(CR'2)n-COOM wherein R is C7-23 hydrocarbyl group, n is 1 to 4, m is hydrogen or a cationic counterion, and the R' groups are H, C1-4 alkyl or a group -(CH2)m-COOM where m is 1 to 4 and M is as defined above, with the proviso that no more than one R' group is the group -(CH2)m-COOM. The first surfactant and the second surfactant are in the weight ratio of 1:10 to about 10:1. Also described is a herbicidal composition comprising a glyphosate herbicide and the first surfactant and second surfactant as defined above.