MANAGEMENT OF 1,3-DICHLOROPROPENE IN PINEAPPLE FOR EFFICACY AND REDUCED VOLATILE LOSSES

Two application methods, single- and double-chisel injection of the fu migant nematicide 1,3-dichloropropene (1,3-D) were evaluated for effic acy and environmental fate in pineapple field experiments. The objecti ves were to compare the 1,3-D soil distribution between injection meth ods, evaluate volatile losses to the atmosphere, and to determine effi cacy with each method. In a small-plot field experiment, 1,3-D (224, 3 37, and 393 1 ha(-1)) was manually injected 30 cm deep with fumiguns t o simulate the commercial practice of a single- or double-chisel injec tion per planting bed. 1,3-D concentrations in the soil atmosphere and in soil samples were determined and compared to nematode control. In two large-scale field experiments, 1,3-D (2241 ha(-1)) was applied wit h commercial injection equipment with and without polyethylene mulch. Air monitoring for 1,3-D showed a reduction in 1,3-D air emissions wit h single-chisel injection compared with double-chisel injection. In al l experiments, the two injection methods resulted in equivalent 1,3-D concentrations in the plant line. Single-chisel injection resulted in improved retention of 1,3-D within the planting bed as shown by low 1, 3-D soil concentrations in the interbed. Nematode counts and bioassay studies found equivalent nematode control in the planting bed with eit her injection method. The single-chisel method, however, resulted in r educed nematode control in the interbed region.