Effect of temperature,organic amendment rate and moisture content on the degradation of 1,3‐dichloropropene in soil

1,3‐Dichloropropene (1,3‐D), which consists of two isomers, (Z)‐ and (E)‐1,3‐D, is considered to be a viable alternative to methyl bromide, but atmospheric emission of 1,3‐D is often associated with deterioration of air quality. To minimize environmental impacts of 1,3‐D, emission control strategies are in need of investigation. One approach to reduce 1,3‐D emissions is to accelerate its degradation by incorporating organic amendments into the soil surface. In this study, we investigated the ability of four organic amendments to enhance the rate of degradation of (Z)‐ and (E)‐1,3‐D in a sandy loam soil. Degradation of (Z)‐ and (E)‐1,3‐D was well described by first‐order kinetics, and rates of degradation for the two isomers were similar. Composted steer manure (SM) was the most reactive of the organic amendments tested. The half‐life of both the (Z)‐ and (E)‐isomers in unamended soil at 20 °C was 6.3 days; those in 5% SM‐amended soil were 1.8 and 1.9 days, respectively. At 40 °C, the half‐life of both isomers in 5% SM‐amended soil was 0.5 day. Activation energy values for amended soil at 2, 5 and 10% SM were 56.5, 53.4 and 64.5 kJ mol^?1, respectively. At 20 °C, the contribution of degradation from biological mechanisms was largest in soil amended with SM, but chemical mechanisms still accounted for more than 58% of the (Z)‐ and (E)‐1,3‐D degradation. The effect of temperature and amendment rate upon degradation should be considered when describing the fate and transport of 1,3‐D isomers in soil. Use of organic soil amendments appears to be a promising method to enhance fumigant degradation and reduce volatile emissions. Published in 2001 for SCI by John Wiley & Sons, Ltd     

Higher-tier assessment of the potential for groundwater issues due to the use of 1,3-D soil fumigant; evaluation of the active ingredient, metabolites and potentially related chlorinated compounds

BACKGROUND: 1,3‐Dichloropropene (1,3‐D, CAS No. 542‐75‐6) is a broad‐spectrum soil fumigant used to control numerous species of soilborne plant‐parasitic nematodes. 1,3‐D consists of two isomers, (Z)‐ and (E)‐1,3‐D. There are a number of low‐level chlorinated compounds that could potentially be produced as a part of the 1,3‐D manufacturing process. 1,3‐D and its metabolites, as well as potentially related chlorinated compounds, represent potential groundwater contaminants. RESULTS: This study has investigated the hydrolytic stability, under biotic and abiotic conditions in the laboratory, of an extensive representative list of 1,3‐D and potentially related chlorinated compounds in order to predict their environmental fate. All of these compounds showed intrinsic hydrolytic instability under both abiotic and biotic test conditions. Furthermore, a monitoring programme was carried out. Twenty‐five wells were monitored in five Italian regions characterised by historical and existing use of 1,3‐D. The parent compound, its two major metabolites and potentially related chlorinated compounds were not detected in the well water at > 0.1 µg L^?1 at any sampling location. CONCLUSION: The soil fumigant (E,Z)‐1,3‐D, its metabolites and potentially related chlorinated compounds constitute a low risk to groundwater. Copyright © 2011 Society of Chemical Industry     

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.), two major 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 g m^?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. Copyright © 2012 Society of Chemical Industry     

含香豆素基团的二氯丙烯类衍生物的合成及杀虫活性

以丙二酸二乙酯、间苯二酚和1,1,3-三氯丙烯等为原料,经取代、环合、缩合等反应合成了9个含有香豆素基团的二氯丙烯类衍生物,化合物结构经IR、 1H NMR、 MS及元素分析确证。初步的生物活性测定结果表明,该类化合物在400 mg/L质量浓度下对小菜蛾Plutella xylostella有较好的杀虫活性,其中化合物 5e 对小菜蛾的致死率达到93%。     

Surface application of ammonium thiosulfate fertilizer to reduce volatilization of 1,3‐dichloropropene from soil

Atmospheric emission of the soil fumigant 1,3‐dichloropropene (1,3‐D) is of environmental concern because of its toxicity and carcinogenicity. Thiosulfate fertilizers have been found to rapidly transform 1,3‐D in soil to non‐volatile ions which are less toxic. We investigated the use of surface application of ammonium thiosulfate (ATS) for reducing 1,3‐D volatilization. In packed soil columns, emission of 1,3‐D applied by sub‐surface injection decreased with increasing ATS application rate and the amount of water used for delivering ATS. When ATS was applied in 9 mm water at 64 g m⁻², total 1,3‐D emission was reduced by 61%. The reduction was 89% when ATS was applied at 193 g m⁻². Bioassays showed that ATS application did not affect the effectiveness of 1,3‐D for controlling citrus nematodes. In field plots where a 1,3‐D emulsified formulation was applied via sub‐surface drip, surface spray of ATS reduced 1,3‐D emissions by 50%, and by 71% when the surface was also covered with polyethylene film. ATS application had no effect on the efficacy of root‐knot nematode control or tomato yields. These results suggest that surface application of thiosulfate fertilizers may be a feasible and effective strategy for minimizing 1,3‐D emissions. © 2000 Society of Chemical Industry     

Fumigation toxicity of volatile natural and synthetic cyanohydrins to stored-product pests and activity as soil fumigants

Insecticidal fumigation toxicity of natural and synthetic cyanohydrins was evaluated with four stored-product pests: the lesser grain borer, Rhyzopertha dominica (F), the red flour beetle, Tribolium castaneum Herbst, the saw-toothed grain beetle Oryzaephilus surinamensis L, the maize weevil, Sitophilus zeamais (Motsch) and the house fly, Musca domestica L. The fumigation LC50 values were calculated by probit analysis. For house flies, all but one of the cyanohydrins tested were more potent than 1,3-dichloropropene (Telone). Three were as efficacious as chloropicrin. For the lesser grain borer, all cyanohydrins tested were more insecticidal than dichloropropene, and all but one were more potent than chloropicrin. Four were as insecticidal as dichlorvos. The acetate of 1-cyano-1-hydroxy-2-propene (CHP-ace) was also tested in soil for antifungal and antibacterial activity, and inhibition of weed seed germination. CHP-ace reduced the total soil bacterial and fungal counts significantly, and was effective in inhibiting the germination of weed seeds in soil, indicating a broad spectrum of activity as a soil fumigant.     

Fumigant combinations for Cyperus esculentum L control

The phase-out of methyl bromide as a soil fumigant has stimulated research into the use of other soil fumigants for weed control. Methyl bromide, methyl iodide, propargyl bromide, 1,3-dichloropropene (1,3-D) and metam-sodium were tested alone and in combination with chloropicrin in laboratory experiments to determine their efficacy against Cyperus esculentus L (yellow nutsedge) tubers. Propargyl bromide and metam-sodium were the most efficacious fumigants tested, with EC50 values of 3.7 and 6.5 microM, respectively. The relative potencies of methyl iodide and chloropicrin were not significantly different but were 2.6 and 2.9 times more potent than methyl bromide, respectively. The EC50 values for all fumigants other than 1,3-D were significantly lower than that of methyl bromide. Combining each fumigant with 17% chloropicrin resulted in a synergistic interaction. The greatest increase in potency between the expected result and the actual result was a relative potency of 3.8 with the methyl bromide/chloropicrin combination. The smallest increase in efficacy was with propargyl bromide and chloropicrin, with a relative potency of 1.5. There was no significant difference between the EC50 values of methyl bromide/chloropicrin and methyl iodide/chloropicrin combinations. Combining 1,3-D with 17% chloropicrin resulted in an EC50 value for C. esculentus control similar to that of methyl iodide applied alone.