The combination of 1,3-dichloropropene＋dimethyl disulfide （1,3-D＋DMDS）, which forms a pre-plant soil fumigant, can provide a substitute for the environmentally unfriendly methyl bromide （MB）. Three greenhouse tr...The combination of 1,3-dichloropropene＋dimethyl disulfide （1,3-D＋DMDS）, which forms a pre-plant soil fumigant, can provide a substitute for the environmentally unfriendly methyl bromide （MB）. Three greenhouse trials were performed to evaluate the root-knot nematode and soilborne fungi control efficacy in the suburbs of Beijing in China in 2010-2014. Randomized blocks with three replicates were designed in each trial. The combination of 1,3-D＋DMDS （10＋30 g m-2） significantly controlled Meloidogyne incognita, effectively suppressed the infestation of Fusarium oxysporum and Phytophthora spp., and successfully provided high commercial fruit yields （equal to MB but higher than 1,3-D or DMDS）. The fumigant soil treatments were significantly better than the untreated controls. These results indicate that 1,3-D＋DMDS soil treatments can be applied by soil injection or chemigation as a promising MB alternative against soilborne pests in cucumber in China.展开更多
Photochemical production of carbonyl sulfide（COS）,carbon disulfide（CS_2） and dimethyl sulfide（DMS） was intensively studied in the water from the Aohai Lake of Beijing city.The lake water was found to be highly s...Photochemical production of carbonyl sulfide（COS）,carbon disulfide（CS_2） and dimethyl sulfide（DMS） was intensively studied in the water from the Aohai Lake of Beijing city.The lake water was found to be highly supersaturated with COS,CS_2 and DMS,with their initial concentrations of 0.91 ± 0.073 nmol/L,0.55 ± 0.071 nmol/L and 0.37 ± 0.062 nmol/L,respectively.The evident photochemical production of COS and CS_2 in the lake water under irradiation of 365 nm and 302 nm indicated that photochemical production of them might be the reason for their supersaturation.The similar dependence of wavelength and oxygen for photochemical production of COS,CS_2 and DMS implied that they might be from the same precursors.The water cage effect was found to favor COS production but inhibit CS_2and DMS formation,indicating that COS photochemical production was mainly from direct degradation of the precursors and the formation of CS_2 and DMS needed intermediates via combination of carbon-centered radicals and sulfur-centered radicals.The above assumptions were further confirmed by simulation experiments with addition of carbonyls and amino acids（cysteine and methionine）,and the photochemical formation mechanisms for COS,CS_2 and DMS in water were derived from the investigations.展开更多
基金supported by Beijing Team-Innovation, Modern Agricultural and Industrial Technology Innovation System of China (2010B064)the Program on Substituted Technology for Methyl Bromide in China (Special Finance of Chinese Ministry of Agriculture, 2110402) over the years
文摘The combination of 1,3-dichloropropene＋dimethyl disulfide （1,3-D＋DMDS）, which forms a pre-plant soil fumigant, can provide a substitute for the environmentally unfriendly methyl bromide （MB）. Three greenhouse trials were performed to evaluate the root-knot nematode and soilborne fungi control efficacy in the suburbs of Beijing in China in 2010-2014. Randomized blocks with three replicates were designed in each trial. The combination of 1,3-D＋DMDS （10＋30 g m-2） significantly controlled Meloidogyne incognita, effectively suppressed the infestation of Fusarium oxysporum and Phytophthora spp., and successfully provided high commercial fruit yields （equal to MB but higher than 1,3-D or DMDS）. The fumigant soil treatments were significantly better than the untreated controls. These results indicate that 1,3-D＋DMDS soil treatments can be applied by soil injection or chemigation as a promising MB alternative against soilborne pests in cucumber in China.
基金supported through Strategic Priority Research Program projects(B)of the Chinese Academy of Sciences(No.XDB05010100)the Special Fund for Environmental Research in the Public Interest(No.201509002)the National Natural Science Foundation of China(Nos.21477142,41575121,41203070)
文摘Photochemical production of carbonyl sulfide（COS）,carbon disulfide（CS_2） and dimethyl sulfide（DMS） was intensively studied in the water from the Aohai Lake of Beijing city.The lake water was found to be highly supersaturated with COS,CS_2 and DMS,with their initial concentrations of 0.91 ± 0.073 nmol/L,0.55 ± 0.071 nmol/L and 0.37 ± 0.062 nmol/L,respectively.The evident photochemical production of COS and CS_2 in the lake water under irradiation of 365 nm and 302 nm indicated that photochemical production of them might be the reason for their supersaturation.The similar dependence of wavelength and oxygen for photochemical production of COS,CS_2 and DMS implied that they might be from the same precursors.The water cage effect was found to favor COS production but inhibit CS_2and DMS formation,indicating that COS photochemical production was mainly from direct degradation of the precursors and the formation of CS_2 and DMS needed intermediates via combination of carbon-centered radicals and sulfur-centered radicals.The above assumptions were further confirmed by simulation experiments with addition of carbonyls and amino acids（cysteine and methionine）,and the photochemical formation mechanisms for COS,CS_2 and DMS in water were derived from the investigations.
