AbstractThe fumigant nematicide, 1,3‐dichloropropene (1,3‐D VL; ‘Telone’ II) and a soluble liquid formulation, 1,3‐D SL were tested in a pineapple field experiment to evaluate the vapor movement of the two formulations in soil gas as well as the movement and persistence of 1,3‐D SL in soil profiles. Prior to planting, 1,3‐D VL (407 kg ha−1) was hand‐injected into the soil in two parallel rows per planting bed to approximate the practice of chisel injection. 1,3‐D SL (407 kg ha−1) was applied with 6 mm of water by drip irrigation through a drip tube in the center of the bed. Post‐plant applications of 1,3‐D SL (113 kg ha−1) were made at three‐month intervals during a two‐crop cycle. 1,3‐D concentrations in soil gas were lower at the plant line in the drip treatment compared with the 1,3‐D VL treatment, owing to differences in application method and fumigant placement. 1,3‐D in the vapor phase reached peak concentrations 24 h after injection in the 1,3‐D VL treatment compared with a peak at 48 h in the drip treatment. Post‐plant applications of 1,3‐D SL resulted in a three‐fold difference in peak 1,3‐D soil gas concentrations between replicate applications, the concentration being inversely related to soil moisture at the time of sampling. Drip application of 1,3‐D SL resulted in a relatively uniform distribution of 1,3‐D across the bed and to a depth of 45 cm. There was no effect of formulation on downward movement of 1,3‐D and persistence in soil profiles sampled two weeks and one month after application. Rainfall which occurred 9 days after pre‐plant 1,3‐D fumigation resulted in leaching of 1,3‐D to a depth of 150 cm in soil profiles. Due to the short half‐life of 1,3‐D, significant penetration of 1,3‐D in the soil was observed only when irrigation or rainfall occurred soon after application.