Evaluation of the combination of 1,3-dichloropropene and dazomet as an efficient alternative to methyl bromide for cucumber production in China

BACKGROUND: The combination of 1,3-dichloropropene (1,3-D) and dazomet (DZ) offers a potential alternative to methyl bromide (MB) for soil disinfection. MB is scheduled to be withdrawn from routine use by 2015 in developing countries. Combination treatments of 1,3-D + DZ were evaluated in a laboratory study and in two commercial cucumber fields. RESULTS: Laboratory studies found that nearly all of the tested combinations of 1,3-D and DZ displayed positive synergistic activity on root-knot nematodes (Meloidogyne spp.), twomajor soilborne fungi (Fusarium spp. and Phytophthora spp.) and the seeds of two major weed species (Digitaria sanguinalis and Abutilon theophrasti). Field trials revealed that the combination of 1,3-D and DZ (at 10 + 25 gm-2) successfully suppressed Meloidogyne spp. root galling, sharply reduced Fusarium spp. and Phytophthora spp. and maintained high cucumber yields. The combination treatment of 1,3-D + DZ was more effective than 1,3-D or DZ alone and provided results similar to methyl bromide with respect to pest control, plant mortality, plant height, yield and income. All of the treatments were significantly better than the non-treated control. CONCLUSION: The results indicate that the tested combination of 1,3-D and DZ offers an efficient alternative to methyl bromide for cucumber production. (C) 2012 Society of Chemical Industry