12%difenoconazole+fluxapyroxad SC(commercial name:Jiangong)was first released by BASF in China in 2016.It has been registered to control many diseases,including pear scab,apple Alternaria leaf spot,tomato early blight...12%difenoconazole+fluxapyroxad SC(commercial name:Jiangong)was first released by BASF in China in 2016.It has been registered to control many diseases,including pear scab,apple Alternaria leaf spot,tomato early blight,cucumber powdery mildew,etc.This study evaluated the bioactivity of Jiangong against Alternaria alternata and explored variations of phyllosphere microorganisms in both asymptomatic and tobacco brown spot leaves at different persistence periods(0,5,10,and 15 days post-fungicide application)using high-throughput sequencing technology.The results indicated that Jiangong effectively inhibited mycelial growth(average EC_(50) value of 0.51μg/mL),conidia germination(average EC_(50) value of 3.47μg/mL),and the carbon metabolism of A.alternata.Both asymptomatic and symptomatic leaves presented complex microbial communities.Higher fungal diversity was noted in asymptomatic leaves,while higher bacterial diversity was found in symptomatic leaves.After application,the diversity and abundance of microbial community structures in both types of leaves changed over time.Fungal microbiome communities showed greater sensitivity than bacterial groups,with the microbiome communities of asymptomatic leaves being more affected than those of symptomatic leaves.Fungal community diversity decreased for both symptomatic and asymptomatic leaves after 5 days of application,while the diversity of fungal community in symptomatic leaves showed an upward trend after 10 days of application.Meanwhile,bacterial community diversity increased in both symptomatic and asymptomatic leaves after 5 days of application but then declined in asymptomatic leaves after 15 days.The abundance of the dominant function group of phyllosphere bacteria(metabolism,genetic information processing,environmental information processing)was not affected by the application of Jiangong.However,the abundance of the dominant function group of phyllosphere fungi(animal pathogen-endophyte-wood saprotroph,endophyte-plant pathogen,plant pathogen-undefined saprotroph)was significantly affected by the application of Jiangong,and high variation was found in symptomatic leaves than that of asymptomatic leaves.The application of Jiangong-induced alterations in the community structure of the tobacco phyllosphere microbiome provides a basis for future tobacco brown spot control strategies based on phyllospheric microecology.展开更多
Resistance of Venturia inaequalis to the first IBS triazoles occurred in the 80’s in Italy and other countries. Successively number of applications sensibly decreased and problems of resistance to IBS generally disap...Resistance of Venturia inaequalis to the first IBS triazoles occurred in the 80’s in Italy and other countries. Successively number of applications sensibly decreased and problems of resistance to IBS generally disappeared. In 2010 suspects of resistance to the newer IBS difenoconazole, the actually most used IBS, appeared in several countries. In vitro tests the results confirmed the previous researches: the monoconidia from populations which were poorly controlled showed moderate reduced sensitivity respect to well controlled and wild-types. New in vivo tests were realized with preventive and curative applications on seedlings. No different activity among the three types of populations (poorly, well-controlled and wild-types) was found in preventive applications. On the contrary, in curative applications, wild-types and well controlled populations showed a visible and statistically significant activity respect to the poorly controlled. A survey of sensitivity to difenoconazole was carried out in two Italian apple areas in 2013-2015 and showed the presence of populations resistant to difenoconazole. Probably the cause of the resistance spread was the increase of the number of applications of this IBS in the last years. However the problem appears more complex because nowadays resistance regards about all fungicides and with a higher severity respect previous decades. An increase of virulence of V. inaequalis strains appears to be the cause of this situation also for the high presence of cultivars with high or moderate susceptibility to scab. Foreseeable remedies consist in a differentiate and appropriate setting of each chemical groups of fungicides in apple scab control, but in long terms new strategies in apple cultivation should be necessary.展开更多
A field experiment was employed to study the degradation of triadimefon and difenoconazole residues in strawberry and soil. The results showed that the degradation of both the two kinds of pesticides was in accordance...A field experiment was employed to study the degradation of triadimefon and difenoconazole residues in strawberry and soil. The results showed that the degradation of both the two kinds of pesticides was in accordance with the first order kinetic equation. The half-lives of difenoconazole in strawberry fruit, strawberry stem leaf and soil were 4.09, 8.21 and 13.38 d, respectively; and the half-lives of triadimefon in strawberry fruit, strawberry stem and leaf and soil were 3.38, 5.31 and 15.64 d, respectively. The maximum residue limit （MRL） of difenoconazole in strawberry was recommended as 0.5 mg/kg, and 10% difenoconazole WG and 20% triadimefon EC should be applied four times with a safety interval of 7 d according to the amounts of 100 and 60 g a. i./hm2,respectively.展开更多
A new synthesis method of difenoconazole is studied.Difenoconazole is prepared from m-dichlorobenzene by Friedel Crafts reaction,cyclization,bromination,nucleophilic substitution and etherification.The new process imp...A new synthesis method of difenoconazole is studied.Difenoconazole is prepared from m-dichlorobenzene by Friedel Crafts reaction,cyclization,bromination,nucleophilic substitution and etherification.The new process improves the selectivity of the reaction and simplified the pu-rification process.The total yield of this process is 84%,which provides a green and economical synthetic route for industrialization.展开更多
基金Supported by China National Tobacco Corporation[No.110202101048(LS-08)]Hundred’Level Innovative Talent Foundation of Guizhou Province(No.GCC[2022]028-1,GCC[2023]108)+2 种基金Guizhou Science Technology Foundation(No.ZK[2021]Key036)the National Natural Science Foundation of China(No.32160522)Guizhou Province Applied Technology Research and Development Funding Post-subsidy Project and Guizhou Tobacco Company(No.2020XM03,2020XM22,2024XM06).
文摘12%difenoconazole+fluxapyroxad SC(commercial name:Jiangong)was first released by BASF in China in 2016.It has been registered to control many diseases,including pear scab,apple Alternaria leaf spot,tomato early blight,cucumber powdery mildew,etc.This study evaluated the bioactivity of Jiangong against Alternaria alternata and explored variations of phyllosphere microorganisms in both asymptomatic and tobacco brown spot leaves at different persistence periods(0,5,10,and 15 days post-fungicide application)using high-throughput sequencing technology.The results indicated that Jiangong effectively inhibited mycelial growth(average EC_(50) value of 0.51μg/mL),conidia germination(average EC_(50) value of 3.47μg/mL),and the carbon metabolism of A.alternata.Both asymptomatic and symptomatic leaves presented complex microbial communities.Higher fungal diversity was noted in asymptomatic leaves,while higher bacterial diversity was found in symptomatic leaves.After application,the diversity and abundance of microbial community structures in both types of leaves changed over time.Fungal microbiome communities showed greater sensitivity than bacterial groups,with the microbiome communities of asymptomatic leaves being more affected than those of symptomatic leaves.Fungal community diversity decreased for both symptomatic and asymptomatic leaves after 5 days of application,while the diversity of fungal community in symptomatic leaves showed an upward trend after 10 days of application.Meanwhile,bacterial community diversity increased in both symptomatic and asymptomatic leaves after 5 days of application but then declined in asymptomatic leaves after 15 days.The abundance of the dominant function group of phyllosphere bacteria(metabolism,genetic information processing,environmental information processing)was not affected by the application of Jiangong.However,the abundance of the dominant function group of phyllosphere fungi(animal pathogen-endophyte-wood saprotroph,endophyte-plant pathogen,plant pathogen-undefined saprotroph)was significantly affected by the application of Jiangong,and high variation was found in symptomatic leaves than that of asymptomatic leaves.The application of Jiangong-induced alterations in the community structure of the tobacco phyllosphere microbiome provides a basis for future tobacco brown spot control strategies based on phyllospheric microecology.
文摘Resistance of Venturia inaequalis to the first IBS triazoles occurred in the 80’s in Italy and other countries. Successively number of applications sensibly decreased and problems of resistance to IBS generally disappeared. In 2010 suspects of resistance to the newer IBS difenoconazole, the actually most used IBS, appeared in several countries. In vitro tests the results confirmed the previous researches: the monoconidia from populations which were poorly controlled showed moderate reduced sensitivity respect to well controlled and wild-types. New in vivo tests were realized with preventive and curative applications on seedlings. No different activity among the three types of populations (poorly, well-controlled and wild-types) was found in preventive applications. On the contrary, in curative applications, wild-types and well controlled populations showed a visible and statistically significant activity respect to the poorly controlled. A survey of sensitivity to difenoconazole was carried out in two Italian apple areas in 2013-2015 and showed the presence of populations resistant to difenoconazole. Probably the cause of the resistance spread was the increase of the number of applications of this IBS in the last years. However the problem appears more complex because nowadays resistance regards about all fungicides and with a higher severity respect previous decades. An increase of virulence of V. inaequalis strains appears to be the cause of this situation also for the high presence of cultivars with high or moderate susceptibility to scab. Foreseeable remedies consist in a differentiate and appropriate setting of each chemical groups of fungicides in apple scab control, but in long terms new strategies in apple cultivation should be necessary.
基金Supported by Tripartite Joint Fund of Science and Technology Department of Guizhou Province(LH[2016]7278)Agricultural Science and Technology Project of Science and Technology Department of Guizhou Province(NZ[2013]3029)+1 种基金Tripartite Joint Fund of Science and Technology Department of Guizhou Province(Key Project)(JLKA[2012]03)Natural Science Research Project of Department of Education of Guizhou Province(2011054)~~
文摘A field experiment was employed to study the degradation of triadimefon and difenoconazole residues in strawberry and soil. The results showed that the degradation of both the two kinds of pesticides was in accordance with the first order kinetic equation. The half-lives of difenoconazole in strawberry fruit, strawberry stem leaf and soil were 4.09, 8.21 and 13.38 d, respectively; and the half-lives of triadimefon in strawberry fruit, strawberry stem and leaf and soil were 3.38, 5.31 and 15.64 d, respectively. The maximum residue limit （MRL） of difenoconazole in strawberry was recommended as 0.5 mg/kg, and 10% difenoconazole WG and 20% triadimefon EC should be applied four times with a safety interval of 7 d according to the amounts of 100 and 60 g a. i./hm2,respectively.
文摘A new synthesis method of difenoconazole is studied.Difenoconazole is prepared from m-dichlorobenzene by Friedel Crafts reaction,cyclization,bromination,nucleophilic substitution and etherification.The new process improves the selectivity of the reaction and simplified the pu-rification process.The total yield of this process is 84%,which provides a green and economical synthetic route for industrialization.
