The highly-damaging root-knot nematode(Meloidogyne spp.,RKN)cannot be reliably controlled using only a nematicide such as fosthiazate because of increasing pest resistance.In laboratory and greenhouse trials,we showed...The highly-damaging root-knot nematode(Meloidogyne spp.,RKN)cannot be reliably controlled using only a nematicide such as fosthiazate because of increasing pest resistance.In laboratory and greenhouse trials,we showed that chloropicrin(CP)or dazomet(DZ)synergized the efficacy of fosthiazate against RKN.The combination significantly extended the degradation half-life of fosthiazate by an average of about 1.25 times.CP or DZ with fosthiazate reduced the time for fosthiazate to penetrate the RKN cuticle compared to fosthiazate alone.CP or DZ combined with low or medium rate of fosthiazate increased the total cucumber yield,compared to the use of each product alone.A low-dose fosthiazate with DZ improved total yield more than a low dose fosthiazate with CP.Extending the half-life of fosthiazate and reducing the time for fosthiazate or fumigant to penetrate the RKN cuticle were the two features that gave the fumigant-fosthiazate combination its synergistic advantage over these products used singularly.This synergy provides the opportunity for farmers to use a low dose of fosthiazate which lowers the risk of RKN resistance.Farmers could combine DZ at 30 g m^-2 with fosthiazate at a low rate of 0.375 g m^-2 to control RKN and adequately control two major soil-borne diseases in cucumber greenhouses.展开更多
Soil flame disinfestation(SFD) is a form of physical disinfestation that can be used both in greenhouses and on field crops. Its use for soil disinfestation in different crop growing conditions makes it increasingly a...Soil flame disinfestation(SFD) is a form of physical disinfestation that can be used both in greenhouses and on field crops. Its use for soil disinfestation in different crop growing conditions makes it increasingly attractive for controlling soilborne pathogens and weeds. But little is known about the effect on weeds and soilbrone diseases. This study reports on greenhouses and field crops in China that determined the efficacy of SFD to control weeds, nematodes and fungi. It also determined the impact of SFD on the soil physical and chemical properties(water content, bulk density, NO3^–-N content, NH4^+-N content, conductivity and organic matter) in three field trials. A second generation SFD machine was used in these trials. SFD treatment significantly reduced weeds(>87.8%) and root-knot nematodes(Meloidogyne incognita)(>98.1%). Plant height and crop yield was significantly increased with SFD treatment. NO3^–-N and NH4^+-N increased after the SFD treatment, and there was also an increase in soil conductivity. Water content, bulk density and organic matter decreased significantly in the soil after the SFD treatment compared to the control. Soil flame disinfestation is a potential technique for controlling weeds and diseases in greenhouses or in fields. SFD is a non-chemical, safe, environmentally-friendly soil disinfection method.展开更多
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
Combined use of chloropicrin （Pic） and 1,3-dicloropropene （1,3-D） is as effective as methyl bromide （MB） at controlling soilborne diseases in many trials and commercial uses. However, Pic and 1,3-D are both high...Combined use of chloropicrin （Pic） and 1,3-dicloropropene （1,3-D） is as effective as methyl bromide （MB） at controlling soilborne diseases in many trials and commercial uses. However, Pic and 1,3-D are both highly volatile and may pose strong exposure risks to humans and the environment. A gelatin capsule formulation containing Pic and 1,3-D has been developed to reduce exposure risks to workers and bystanders and improved application safety. We conducted two experiments in tomato and cucumber greenhouses located in Beijing and Qingdao, China, to study the efficacy of Pic plus 1,3-D gelatin capsules applied at different dosages and soil depths. Results indicated that both injection and gelatin capsules of Pic plus 1,3-D provided good control of soil nematodes and reduced disease index of Fusarium wilt and root-knot nematode. Plant yield of tomato and cucumber treated with gelatin capsules was similar to MB treatment. Based on our results, gelatin capsules applied at a soil depth of 15 cm provided better control of soilborne diseases and led to higher fruit yield compared to an application depth of 5 cm. In conclusion, a gelatin capsule of Pic plus 1,3-D is a promising and novel formulation, which not only shows good efficacy in controlling soilborne diseases, but also reduces potential exposure risks of fumigants.展开更多
Sesquiterpenes in Eupatorium adenophorum are abundant in leaves and have great development potential as biopesticides. The toxicity of sesquiterpenes in immune cells and their corresponding immune functions are not fu...Sesquiterpenes in Eupatorium adenophorum are abundant in leaves and have great development potential as biopesticides. The toxicity of sesquiterpenes in immune cells and their corresponding immune functions are not fully understood. We evaluated the immunotoxicity of two cadinene sesquiterpenes 2-deoxo-2-（acetyloxy）-9-oxoageraphorone（DAOA） and 9-oxo-10,11-dehydro-agerophorone（ODA） by using histopathology and toxicology methods in vitro and in vivo in lymphocytes and natural killer cells in Kunming mice. The mice were given single doses of 75, 150 and 300 mg kg^-1 body weight（BW） of DAOA/ODA every day for a week. S erious damage to the thymus and spleen was found in tissue images with clear lysis reduction numbers and a loosened arrangement of splenocytes and thymocytes to the mice treated with 150–300 mg kg^-1 DAOA/ODA. Mice cytology was also affected with significant cellular alterations, increased splenocytes apoptosis rates（P〈0.01）, proliferation reduction（P〈0.05） and natural killer cells activities reduction（P〈0.05） when given 150–300 mg kg^-1 DAOA/ODA, the severities of which were dose-dependent. Howev er, a 75 mg kg^-1 dose of DAOA/ODA showed no change in tissue or cytology after the 7 day treatment, and therefore was considered to be within acceptable safety parameters. Taken together, cadinene sesquiterpenes, as a type of toxic botanical component, have low environmental risks in small doses and should be further studied for their use as biopesticides.展开更多
基金financial support from the Key Research and Development Program of China (2017YFD0201600)the National Natural Science Foundation of China (31672066)+1 种基金the China Scholarship Council (201704280020)the Agricultural Science and Technology Innovation Program of China over the years
文摘The highly-damaging root-knot nematode(Meloidogyne spp.,RKN)cannot be reliably controlled using only a nematicide such as fosthiazate because of increasing pest resistance.In laboratory and greenhouse trials,we showed that chloropicrin(CP)or dazomet(DZ)synergized the efficacy of fosthiazate against RKN.The combination significantly extended the degradation half-life of fosthiazate by an average of about 1.25 times.CP or DZ with fosthiazate reduced the time for fosthiazate to penetrate the RKN cuticle compared to fosthiazate alone.CP or DZ combined with low or medium rate of fosthiazate increased the total cucumber yield,compared to the use of each product alone.A low-dose fosthiazate with DZ improved total yield more than a low dose fosthiazate with CP.Extending the half-life of fosthiazate and reducing the time for fosthiazate or fumigant to penetrate the RKN cuticle were the two features that gave the fumigant-fosthiazate combination its synergistic advantage over these products used singularly.This synergy provides the opportunity for farmers to use a low dose of fosthiazate which lowers the risk of RKN resistance.Farmers could combine DZ at 30 g m^-2 with fosthiazate at a low rate of 0.375 g m^-2 to control RKN and adequately control two major soil-borne diseases in cucumber greenhouses.
基金supported by the National Key Research and Development Program of China (2017YFD0201600)the Beijing Innovation Consortium of Agriculture Research System, China (BAIC01-2017)
文摘Soil flame disinfestation(SFD) is a form of physical disinfestation that can be used both in greenhouses and on field crops. Its use for soil disinfestation in different crop growing conditions makes it increasingly attractive for controlling soilborne pathogens and weeds. But little is known about the effect on weeds and soilbrone diseases. This study reports on greenhouses and field crops in China that determined the efficacy of SFD to control weeds, nematodes and fungi. It also determined the impact of SFD on the soil physical and chemical properties(water content, bulk density, NO3^–-N content, NH4^+-N content, conductivity and organic matter) in three field trials. A second generation SFD machine was used in these trials. SFD treatment significantly reduced weeds(>87.8%) and root-knot nematodes(Meloidogyne incognita)(>98.1%). Plant height and crop yield was significantly increased with SFD treatment. NO3^–-N and NH4^+-N increased after the SFD treatment, and there was also an increase in soil conductivity. Water content, bulk density and organic matter decreased significantly in the soil after the SFD treatment compared to the control. Soil flame disinfestation is a potential technique for controlling weeds and diseases in greenhouses or in fields. SFD is a non-chemical, safe, environmentally-friendly soil disinfection method.
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the financial support from the projects of Dow Agro Sciences, Ministry of Agriculture of China (2110402)the Beijing Agriculture Innovation Consortium (BAIC01-2017) over the years
文摘Combined use of chloropicrin （Pic） and 1,3-dicloropropene （1,3-D） is as effective as methyl bromide （MB） at controlling soilborne diseases in many trials and commercial uses. However, Pic and 1,3-D are both highly volatile and may pose strong exposure risks to humans and the environment. A gelatin capsule formulation containing Pic and 1,3-D has been developed to reduce exposure risks to workers and bystanders and improved application safety. We conducted two experiments in tomato and cucumber greenhouses located in Beijing and Qingdao, China, to study the efficacy of Pic plus 1,3-D gelatin capsules applied at different dosages and soil depths. Results indicated that both injection and gelatin capsules of Pic plus 1,3-D provided good control of soil nematodes and reduced disease index of Fusarium wilt and root-knot nematode. Plant yield of tomato and cucumber treated with gelatin capsules was similar to MB treatment. Based on our results, gelatin capsules applied at a soil depth of 15 cm provided better control of soilborne diseases and led to higher fruit yield compared to an application depth of 5 cm. In conclusion, a gelatin capsule of Pic plus 1,3-D is a promising and novel formulation, which not only shows good efficacy in controlling soilborne diseases, but also reduces potential exposure risks of fumigants.
基金supported by the Special Non-profit Agricultural Industrial Research Fund of China (201103027)
文摘Sesquiterpenes in Eupatorium adenophorum are abundant in leaves and have great development potential as biopesticides. The toxicity of sesquiterpenes in immune cells and their corresponding immune functions are not fully understood. We evaluated the immunotoxicity of two cadinene sesquiterpenes 2-deoxo-2-（acetyloxy）-9-oxoageraphorone（DAOA） and 9-oxo-10,11-dehydro-agerophorone（ODA） by using histopathology and toxicology methods in vitro and in vivo in lymphocytes and natural killer cells in Kunming mice. The mice were given single doses of 75, 150 and 300 mg kg^-1 body weight（BW） of DAOA/ODA every day for a week. S erious damage to the thymus and spleen was found in tissue images with clear lysis reduction numbers and a loosened arrangement of splenocytes and thymocytes to the mice treated with 150–300 mg kg^-1 DAOA/ODA. Mice cytology was also affected with significant cellular alterations, increased splenocytes apoptosis rates（P〈0.01）, proliferation reduction（P〈0.05） and natural killer cells activities reduction（P〈0.05） when given 150–300 mg kg^-1 DAOA/ODA, the severities of which were dose-dependent. Howev er, a 75 mg kg^-1 dose of DAOA/ODA showed no change in tissue or cytology after the 7 day treatment, and therefore was considered to be within acceptable safety parameters. Taken together, cadinene sesquiterpenes, as a type of toxic botanical component, have low environmental risks in small doses and should be further studied for their use as biopesticides.
