Six methods of application of DBCP response and best kill in the 0 to 30-cm layer, but in deeper layers injection followed by irrigation gave higher percentage kill. The polythene column experiment indicated that DBCP penetrated, 30-45 cm deep, when applied with irrigation water. Injections at 15- and 23-cm depths resulted in the restricted movement of DBCP within 0 to 30- and 15 to 45-cm depths, respectively. When injections were given at 23-cm depth followed by irrigation, an upward as well as downward movement of the nematicide apparently occurred. The depth of application by spot injection, with or without irrigation apparently is a critical factor in obtaining highest percentage kill of the nematode population.