Table 1. The Effectiveness of DSMA at 4 lb/A in Controlling Dallisgrass in Bermudagrass as Affected by the Addition of a Surfactant

ethylene oxide have generally provided m a x i m u m crabgrass control when applied in mixtures containing diuron. In these and other greenhouse studies at the Delta Branch Experiment Station, Stoneville, Mississippi, ethoxyla ted nonylphenol surfactants containing 15-30 moles of ethylene oxide were also effective in increasing diuron toxicity, but t h e y w e r e comparatively poor in increasing spray-mixture wettability. Surfactants also enhance the activity of herbicides other than diuron. For example, surfactants increase t h e a c t i v i t y of 3,4dichloropropionanil ide (DPA), used for the control of grasses in r ice; 2,2-dichloropropionic acid (dalapon), used primarily for johnsongrass c o n t r o l ; and disodium monomethy la r sena te (DSMA), extensively used in the Midsouth for nutgrass and johnsongrass control. In addition, DSMA is very effective for controlling dal l isgrass in bermudagrass (Fig. 1). The data in Table 1 shows that 0.5% (wt/v) of surfactant increased the control of dallisgrass by 32% over that of DSMA without surfactant.