Published online by Cambridge University Press: 12 June 2017
Dicamba (3,6-dichloro-o-anisic acid) dissipated in 4 weeks and in 9 to 16 weeks when sprayed on grassland soils of Texas at 0.28 kg/ha and 0.56 kg/ha, respectively. At three of four locations ranging from humid to semiarid and from clay to sandy loam and sampled from 9 to 63 weeks after treatment, usually residues were no deeper than 120 cm and never deeper than 150 cm. However, dicamba residues were detected 120 cm deep 53 weeks after application of granules at 1.68 or 2.24 kg/ha to sand of semiarid grassland. Since dicamba sprays are usually applied at 0.56 kg/ha or less for grassland restoration in Texas, it is unlikely that residues of dicamba will persist in soil through the growing season from spring applications.