Effects of Application Methods and Plastic Covers on Distribution of Cis- and Trans-1,3-Dichloropropene and Chloropicrin in Root Zone

This study examined the effects of three application methods (chisel injection, Avenger coulter injection, and drip irrigation) and two plastic films (polyethylene film [PE] and virtually impermeable film [VIF]) on distribution of cis- and trans- 1,3-dichloropropene (1,3-D) and chloropicrin (CP) in a Florida sandy soil after application of Telone C35 or Telone In-Line. Regardless of application method, VIF retained greater amounts of cis- and trans-1,3-D and CP in the root zone with longer residential time than PE. There was better retention of the three compounds in the root zone when applied with the Avenger coulter injection rig than chisel injection, especially in combination with VIF. Distribution of the three compounds in the root zone was less predictable when applied by drip irrigation. Following drip irrigation, more than 50% of the three compounds in the PE and VIF-covered beds was found near the end of the drip tapes in one experiment, whereas the distribution was much more uniform in the root zone in a second experiment. Among the three biologically active compounds, CP disappeared from the root zone more rapidly than cis- and trans-1,3-D, especially in the PE-covered beds.