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Mary H Chapman - One of the best experts on this subject based on the ideXlab platform.
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relative toxicity of bacillus thuringiensis var tenebrionis to the two spotted spider mite tetranychus urticae koch and its predator metaseiulus occidentalis nesbitt acari tetranychidae and phytoseiidae
Journal of Applied Entomology, 1991Co-Authors: Mary H ChapmanAbstract:Abstract Bacillus thuringiensis var. tenebrionis (Btte) Wettable Powders were tested in the laboratory to determine their relative toxicity to the two-spotted spider mite (Tetranychus urticae Koch) and its predator Metaseiulus (= Typhlodromus) occidentalis (Nesbitt). These microbial preparations, when tested at 0.1X, 0.5X, and 1.0X the recommended field rate of 0.9 kg ai/75.7 l/acre (2.0 lb ai/20.0 gal/acre) caused little mortality to adult females of T. urticae but were considerably more toxic to M. occidentalis females at 48 h. Female T. urticae exhibited 90.0 ± 14.2 % survival vs. 26.0 ± 23.4 % survival for M. occidentalis at the field rate. Starvation of female predators for 24 h prior to treatment with Btte Wettable powder significantly increased mortality. Neither predator nor spider mite eggs treated with Btte Wettable powder at the field rate suffered a depression in hatch rate (98.0% and 97.2 % hatch, respectively, of eggs treated when 24 h old). However, only 65.0 % of the resulting immature predators reached adulthood compared to 88.8 % of the immature spider mites. Female predators which survived treatment as eggs and developed on residues did not show a significant decrease in fecundity. Thus, under these laboratory conditions, Btte was moderately toxic to predator mites. Finally, treatment of M. occidentalis females with other Btte products (Mycogen M-ONE® and Sandoz Trident®) and with B. t. var. kurstaki (Dipel 2X) also resulted in significant mortality. Zusammenfassung Zur Wirkung von Bacillus thuringiensis var. tenebrionis auf Tetranychus urticae Koch und dessen Rauber, Metaseiulus occidentalis (Nesbitt) (Acori, Tetranychidae und Phytoseiidae) Im Labor wurden pulverformig formulierte Site-Praparate hinsichtlich ihrer Wirkung auf Tetranychus urticae und dessen Rauber, Metaseiulus occidentalis getestet. Die Praparate, die in 0,1-, 0,5- und 1,0-fachen Dosis der im Freiland ublichen Ausbringungsmenge von 0,9 kg a.i./75,7 l/acre appliziert wurden, bewirkten bei adulten Weibchen von T. urticae nur eine geringe Mortalitat. Jedoch wurde nach 48 h bei M. occidentalis-Weibchen eine deutliche Wirkung festgestellt. Bei Anwendung der ublichen Freilanddosis uberlebten 90,0 ± 14,2 % der T. urticae-Weibchen, dagegen nur 26,0 ± 23,4 % der M. occidentalis-Wibchen. Eine Hungerphase von 24 h vor der Btte-Behandlung erhohte die Mortalitat von M. occidentalis deutlich. Die Schlupfrate der Eier beider Arten, die zum Zeitpunkt der Btte-Behandlung 24 h alt waren, wurde nicht beeintrachtigt. Jedoch entwickelten sich nur 65 % der geschlupften M. occidentalis-Larven zu Imagines, im Gegensatz zu 88,8 % bei T. urticae. Weibliche Imagines von M. occidentalis, die die Btte-Behandlung im Eistadium uberlebt hatten, zeigten keine reduzierte Fekunditat. Die Untersuchungen zeigen, das Btte unter Laborbedingungen eine gewisse toxische Wirkung auf rauberische Milben hat. Auch die Behandlung von M. occidentalis-Weibchen mit anderen Btte-Produkten (Mycogen m-one® und Sandoz Trident®) und mit B.t. var. kurstaki (Dipel 2x) bewirkten eine signifikante Mortalitat.
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Relative toxicity of Bacillus thuringiensis var. tenebrionis to the two‐spotted spider mite (Tetranychus urticae Koch) and its predator Metaseiulus occidentalis (Nesbitt) (Acari, Tetranychidae and Phytoseiidae)
Journal of Applied Entomology, 1991Co-Authors: Mary H ChapmanAbstract:Abstract Bacillus thuringiensis var. tenebrionis (Btte) Wettable Powders were tested in the laboratory to determine their relative toxicity to the two-spotted spider mite (Tetranychus urticae Koch) and its predator Metaseiulus (= Typhlodromus) occidentalis (Nesbitt). These microbial preparations, when tested at 0.1X, 0.5X, and 1.0X the recommended field rate of 0.9 kg ai/75.7 l/acre (2.0 lb ai/20.0 gal/acre) caused little mortality to adult females of T. urticae but were considerably more toxic to M. occidentalis females at 48 h. Female T. urticae exhibited 90.0 ± 14.2 % survival vs. 26.0 ± 23.4 % survival for M. occidentalis at the field rate. Starvation of female predators for 24 h prior to treatment with Btte Wettable powder significantly increased mortality. Neither predator nor spider mite eggs treated with Btte Wettable powder at the field rate suffered a depression in hatch rate (98.0% and 97.2 % hatch, respectively, of eggs treated when 24 h old). However, only 65.0 % of the resulting immature predators reached adulthood compared to 88.8 % of the immature spider mites. Female predators which survived treatment as eggs and developed on residues did not show a significant decrease in fecundity. Thus, under these laboratory conditions, Btte was moderately toxic to predator mites. Finally, treatment of M. occidentalis females with other Btte products (Mycogen M-ONE® and Sandoz Trident®) and with B. t. var. kurstaki (Dipel 2X) also resulted in significant mortality. Zusammenfassung Zur Wirkung von Bacillus thuringiensis var. tenebrionis auf Tetranychus urticae Koch und dessen Rauber, Metaseiulus occidentalis (Nesbitt) (Acori, Tetranychidae und Phytoseiidae) Im Labor wurden pulverformig formulierte Site-Praparate hinsichtlich ihrer Wirkung auf Tetranychus urticae und dessen Rauber, Metaseiulus occidentalis getestet. Die Praparate, die in 0,1-, 0,5- und 1,0-fachen Dosis der im Freiland ublichen Ausbringungsmenge von 0,9 kg a.i./75,7 l/acre appliziert wurden, bewirkten bei adulten Weibchen von T. urticae nur eine geringe Mortalitat. Jedoch wurde nach 48 h bei M. occidentalis-Weibchen eine deutliche Wirkung festgestellt. Bei Anwendung der ublichen Freilanddosis uberlebten 90,0 ± 14,2 % der T. urticae-Weibchen, dagegen nur 26,0 ± 23,4 % der M. occidentalis-Wibchen. Eine Hungerphase von 24 h vor der Btte-Behandlung erhohte die Mortalitat von M. occidentalis deutlich. Die Schlupfrate der Eier beider Arten, die zum Zeitpunkt der Btte-Behandlung 24 h alt waren, wurde nicht beeintrachtigt. Jedoch entwickelten sich nur 65 % der geschlupften M. occidentalis-Larven zu Imagines, im Gegensatz zu 88,8 % bei T. urticae. Weibliche Imagines von M. occidentalis, die die Btte-Behandlung im Eistadium uberlebt hatten, zeigten keine reduzierte Fekunditat. Die Untersuchungen zeigen, das Btte unter Laborbedingungen eine gewisse toxische Wirkung auf rauberische Milben hat. Auch die Behandlung von M. occidentalis-Weibchen mit anderen Btte-Produkten (Mycogen m-one® und Sandoz Trident®) und mit B.t. var. kurstaki (Dipel 2x) bewirkten eine signifikante Mortalitat.
Li Xu - One of the best experts on this subject based on the ideXlab platform.
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determination of 30 carbendazim thiram Wettable Powders by hplc
Journal of Anhui Agricultural Sciences, 2014Co-Authors: Li XuAbstract:[Objective]The aim was to establish detection method with amethanol and water as mobile phase. [Method]A method was introduced for determination of Carbendazim + Thiram Wettable Powders by HPLC with C18column,UV 254 nm detection,methanol + water( V∶ V = 55∶ 45) as mobile phase. [Result]The results showed that the standard deviation was 0. 551 8 and 0. 206 1; the coefficients of variations were 3. 341% and 1. 442%; the average recoveries were 99. 64% and 99. 69%; linear correlations were 0. 999 7 and 0. 999 9 for carbendazim and thirm respectively.[Conclusion] The analysis method of 30% Carbendazim + Thiram Wettable Powders was established with a fast simple, quantitative accuracy,repeatability and high accuracy.
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Determination of 30% Carbendazim + Thiram Wettable Powders by HPLC
Journal of Anhui Agricultural Sciences, 2014Co-Authors: Li XuAbstract:[Objective]The aim was to establish detection method with amethanol and water as mobile phase. [Method]A method was introduced for determination of Carbendazim + Thiram Wettable Powders by HPLC with C18column,UV 254 nm detection,methanol + water( V∶ V = 55∶ 45) as mobile phase. [Result]The results showed that the standard deviation was 0. 551 8 and 0. 206 1; the coefficients of variations were 3. 341% and 1. 442%; the average recoveries were 99. 64% and 99. 69%; linear correlations were 0. 999 7 and 0. 999 9 for carbendazim and thirm respectively.[Conclusion] The analysis method of 30% Carbendazim + Thiram Wettable Powders was established with a fast simple, quantitative accuracy,repeatability and high accuracy.
Derun Zhang - One of the best experts on this subject based on the ideXlab platform.
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a novel method for measuring surface free energy of highly Wettable mineral Powders
Construction and Building Materials, 2019Co-Authors: Derun ZhangAbstract:Abstract This paper develops a novel method to measure the surface free energy for the highly Wettable mineral Powders by means of the capillary rise measurements. In this method, a generalized modified Washburn equation is first derived to capture the spreading wetting mechanism of the probe liquid into the mineral Powders with high wettability. A series of apolar liquids are then selected to conduct the capillary rise test to generate a plot of the measured test results against the square root of the liquid surface tension. Fitting such a plot with a parabolic function, the resultant effective capillary radius and the powder apolar surface energy component can be solved. Then the spreading pressure of two independent liquids is calculated from their capillary rise test results. The polar acid and polar base surface energy components of the highly Wettable Powders can be finally determined by substituting the calculated spreading pressure values into the Good-van Oss-Chaudhury model. The proposed method has been successfully applied to measure the surface free energy for four typical types of mineral Powders. The measured surface free energies of the selected Powders are found to be approximately the same as those obtained from a previous method with different principle. In this regard, the proposed method is validated to be capable of accurately measuring the surface free energy for highly Wettable mineral Powders.
Lyu Yuexing - One of the best experts on this subject based on the ideXlab platform.
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field efficacy of bacillus subtilis Wettable Powders against northern corn leaf blight
Journal of Shanxi Agricultural Sciences, 2013Co-Authors: Lyu YuexingAbstract:To test field efficacy and safety of Bacillus subtilis Wettable Powders against northern corn leaf blight,4 treatments of Bacillus subtilis Wettable Powders spraying were applied in the field in the period of corn leaf blight occurrence.4 treatments all showed control efficacy to northern corn leaf blight.The control efficacy of spraying 300 g every hectare twice,spraying 450 g every hectare once,spraying 300 g every hectare added 75 g organosilicone every hectare twice and spraying 450 g every hectare added 75 g organosilicone every hectare once were 81.25%,68.45%,82.63% and 74.33% respectively.Bacillus subtilis is safe to the corn plants at the tested dosage range.Spraying 300 g Bacillus subtilis every hectare twice exhibit satisfactory control efficacy against northern corn leaf blight,and might be recommended for corn production.
G U Aigu - One of the best experts on this subject based on the ideXlab platform.
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the determination of 50 dinotefuran and pymetrozine Wettable Powders by hplc
Journal of Anhui Agricultural Sciences, 2015Co-Authors: G U AiguAbstract:[Objective] The aim was to establish a determination method of 50% Dinotefuran and Pymetrozine Wettable Powders by HPLC.[Method]The quantitative analysis of Dinotefuran and Pymetrozine WP by HPLC was established with Agilent XDB C18 column and diode array detector,using acetonitrile-water as mobile phase. [Result]Dinotefuran and Pymetrozine showed good linear relationship between 100 mg/L and500 mg/L,and the linear correlations were 0. 999 8 and 0. 999 6,respectively; the standard deviations of Dinotefuran and Pymetrozine were0. 045 and 0. 063; the coefficient of variations were 0. 11% and 0. 61%; the average recoveries were 99. 79% and 99. 64%. [Conclusion]This method has advantages in great efficiency of separation,high accuracy and good reproducibility,and it could be used in the determination of Dinotefuran and Pymetrozine.
