Indaziflam is a new preemergence herbicide for the control of annual grass and broadleaf weeds in various cropping systems including pecan orchards.The objectives of this study were to(1) determine the mobility and dissipation of indaziflam and(2) evaluate herbicide efficacy in a flood-irrigated pecan orchard in southern New Mexico,USA.Indaziflam was applied at 0,35.5,and 73.1 g/ha in areas with(impacted) and without(unimpacted) tree injury symptoms.Soil samples were collected at 0-15,15-30,and 30-46 cm depths 25,63,90,and 125 days after the first herbicide application.Additional soil samples were collected 4,30,and 55 days after the second application.Indaziflam was detected in soil samples collected at each depth,suggesting movement with irrigation water.Indaziflam concentrations decreased with increasing soil depth and time.Indaziflam mass recoveries were greater in the unimpacted area than in the impacted area after the first and second applications.Dissipation half-lives of indaziflam in the soil ranged from 30 to 85 days for total indaziflam recovered from the entire soil profile after the first and second applications in both areas.The percent weed control was similar in the impacted and unimpacted areas for both rates of indaziflam on 25 and 53 days after application;however,on 90 days after the application,percent weed control was lower in the impacted than unimpacted area. Indaziflam is a new preemergence herbicide for the control of annual grass and broadleaf weeds in various cropping systems including pecan orchards. The objectives of this study were to (1) determine the mobility and dissipation of indaziflam and (2) evaluate herbicide efficacy in a flood -irrigated pecan orchard in southern New Mexico, USA. Indaziflam was applied at 0,35.5, and 73.1 g / ha in areas with (impacted) and without (unimpacted) tree injury symptoms. Slip samples were collected at 0-15, 15- 30, and 30-46 cm depths 25, 63, 90, and 125 days after the first herbicide application. Additional soil samples were collected 4, 30, and 55 days after the second application. Indaziflam was detected in soil samples collected at each depth , suggesting movement with irrigation water. Indaziflam mass decreased with increasing soil depth and time. Indaziflam mass recoveries were greater in the unimpacted area than in the impacted area after the first and second applications. Dissipation half-lives of indazi flam in the soil ranged from 30 to 85 days for total indaziflam recovered from the entire soil profile after the first and second applications in both areas. The percent weed control was similar in the impacted and unimpacted areas for both rates of indaziflam on 25 and 53 days after application; however, on 90 days after the application, percent weed control was lower in the impacted than unimpacted area.