C from Raleigh, Nc writes
MSO surfactants are recommended by some herbicide manufacturers.
This product is a non-ionic surfactant that contains alkylaryl polyethoxyethanol. The type of surfactant used will depend upon the weather conditions and the size of the weeds. A methylated seed oil (MSO) would be used when weeds are stressed or the weather is extremely dry. A nonionic product, such as the Surf-Ac 820, can be used in normal weather conditions when weeds and small and well. Oil based surfactants are recommended when using for the control of grasses (unless it specifically says on the label not to use an oil based surfactant).
Answer last updated on: 06/16/2014