Airborne loss represents an important pathway for the attenuation of foliar applied pesticides. The research reported here describes the application of a field chamber technique for measuring airborne loss of the dinitroaniline herbicide pendimethalin (N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitro-benzen- amine) following application to turfgrass. Sanders et al. (1985) demonstrated the utility of this technique for measuring airborne loss of the dinitroaniline anagtrifurain(aaa-trifur-26-dinitr-NN-diprpy-p-tuidene)frmwaste disposal sites. They compared results of field studies with laboratory studies employing a model soil and water disposal system (Sanders and Seiber, 1983). The purpose of the research reported here was to determine the applicability of this field chamber technique to the measurement of pendimethalin airborne loss from turfgrass. The validation of this technique was intended to support the development and implementation of field sampling methodology for the determination of pendimethalin airborne loss from turfgrass utilizing a replicated small plot design (Cooper et a1.,1990). In addition, to monitor foliar residues available for airborne loss a method for determining pendimethalin foliar dislodgeable residues was also developed. Foliar dislodgeable residues are thought to be those residues that are most easily dislodged from the foliar surface, as opposed to more tightly bound or penetrated residues. The measurement of foliar dislodgeable residues was originally designed to assess dermal exposure to workers reentering treated fields (Gunther et al., 1973). However, foliar dislodgeable residues may also be characterized as those residues that are most available for airborne loss, and movement to other parts of the canopy with infiltrating water or by dry deposition (Jenkins et al., 1983; Jenkins et al., 1990).