Over-expression of FPS2 in the cytosol and targeting of its translated product to chloroplasts in arabidopsis led to synthesis of several novel sesquiterpenes, including E-β-farnesene, and induced alarm responses in M. persicae. The results suggest a potential for engineering aphid-resistant strains of arabidopsis.
In a field study carried out at three different locations, the dissipation of spiromesifen on cotton and chili was studied and its DT50, and DT99 were estimated at each location. Spiromesifen was sprayed on chili at 96 and 192 g a.i. ha(-1) and cotton at 120 and 240 g a.i. ha(-1). Samples of chili fruits were drawn at 0, 1, 3, 5, 7, 10, 15, 21, 30 days after treatment and that of cotton seed and lint at first picking and harvest. Soil samples were drawn 30 days after treatment from 0 to 15 and 15 to 30 cm layer. Quantification of residues was done on GC-MS in Selected Ion Monitoring (SIM) mode in mass range 271-274 m/z. The LOQ of this method was found 0.033 microg g(-1), LOD being 0.01 microg g(-1). The DT50 of spiromesifen when applied at recommended doses in chili fruits was found to be 2.18-2.40 days. Ninety-nine percent degradation was found to occur within 14.5-16.3 days after application. Residues of spiromesifen were not detected in cotton seed and lint samples at the first picking. In soil, no residues of spiromesifen were detectable 15 days after treatment.
Mango (Mangiferae indica L.) is an important export horticultural crop of India. Various insects and diseases infest the fruit especially in the fruiting season. The common insect pests are mango leafhopper, mealy bug, leaf webber, inflorescence midge and fruit fly. The major loss of about 60% is due to leafhopper and mango leafhopper. These pests infest the mango at the floral and bud stage to fruit setting, tender leaves and small fruits. The crop protection measures undertaken to control pest infestation involves spray of insecticides along with biological and cultural practices.India produces 65% of the world's mango crop, 9,000,000 MT, but with very little export. Although, Asia accounts for 75% world production, its dominance does not translate into international trade. The presence of pesticide remnants in mango lowers the export quality of mango fruits in the international market. To increase foreign trade, under the WTO regime, it is imperative to produce pesticide free mangoes.The insecticides commonly applied by the farmers are endosulfan, parathion methyl, chlorpyrifos, cypermethrin and fenvalerate. This paper presents a method for the estimation of the multi-class pesticides in mango and their recovery. Materials and MethodSolvents like acetone, dichloromethane, hexane (analytical grade), were distilled before use. Adsorbents neutral alumina and Florisil were activated before use. Pesticide standards of methyl parathion, endosulfan, chlorpyrifos, cypermethrin and fenvalerate were of analytical grade quality. Gas Chromatogram instrumen-Shimadzu GC-17A fitted with an auto-sampler and ECD detector was used for analysis. Other minor equipments required were rotary evaporator and Waring blender, etc.Individual stock standard solutions (1,000 lg/mL) of parathion methyl, endosulfan, chlorpyrifos, cypermethrin and fenvalerate were prepared in hexane (analytical grade). Working standard solutions of each pesticide was prepared by serial dilutions to 100 lg/mL, which was further diluted to 0.1-10 lg/mL as per detector response. All the stock solutions were stored at 4°C. Appropriate aliquot of individual pesticides solutions were taken and a mixture of five pesticides of 100 lg mL -1 concentration were prepared. Mixture solutions of lower concentrations were prepared by serial dilutions using hexane.Limit of detection (LOD) of each pesticide, individually and in a mixture was determined by injecting standard solutions of different concentration levels in duplicate in the GLC. The lowest concentration of the pesticide that gave peak area five times that of background level was considered as LOD.Mango fruit samples without peel (20 g, cut into small pieces) were fortified with the standard mixture at 0.5 lg/mL levels in ten sets each set in triplicate. One control was set-aside for each of the sets. The spiked mango samples were extracted in a Waring blender-Remi make with acetone 50 ml for 2-3 min. The solvent was
Studies were undertaken to analyze the residues of commonly used pesticides viz. chlorpyrifos, endosulfan, dicofol, cypermethrin, fenvalerate, propargite, malathion, phorate, carbendazim, carbosulfan, thiamethoxam, and mancozeb in apple of integrated pest management (IPM) and non-IPM samples collected from the IPM and non-IPM fields of Shimla. We also present a method for the determination of these pesticides in apple samples. Residues of chlorpyrifos, endosulfan, dicofol, cypermethrin, fenvalerate, and propargite were analyzed by gas chromatography, while residues of carbendazim, carbosulfan, and thiamethoxam were analyzed by high-performance liquid chromatography. Residues of mancozeb were determined by a colorimetric method. Recoveries of all of the pesticides ranged from 61.30 to 95.46% at 0.1, 0.2, and 1.0 microg g(-1) levels of fortification with relative standard deviations ranging between 0.8 and 8.7. Apples from IPM and non-IPM orchards were analyzed for these pesticides using a developed method. Except for carbendazim and chlorpyrifos, the residues of all of the pesticides analyzed were below detectable limits. Although residues of carbendazim and chlorpyrifos were below the prescribed limits of maximum residue levels in both IPM and non-IPM orchards, residues were lower in apples from IPM orchards.
Studies were conducted to analyze the residue of commonly used pesticides viz. methyl parathion, chloropyrifos, endosulfan, cypermethrin, fenvalerate, carbendazim, imidacloprid and carbaryl in mango, Dashehari variety, integrated pest management (IPM) and non-IPM samples were collected from the IPM and non-IPM orchards, Lucknow, India. We also present a method for the simultaneous determination of these pesticides in mango samples. Residues of methyl parathion, chloropyriphos, endosulfan, cypermethrin, fenvalerate were extracted from the samples with acetone: cyclohexane: ethyl acetate in the ratio 2:1:1 followed by cleanup using neutral alumina. Analysis was performed by gas chromatography-electron capture detector (GC-ECD) with a megabore column (OV-1). Residues of carbendazim, imidacloprid and carbaryl were extracted with acetone and after cleanup, analysis was performed by high performance liquid chromatography (HPLC) using photo diode array (PDA) detector. Recoveries of all the pesticides ranged between 72.7-110.6%, at 0.1 and 1.0 microg g(-1) level of fortification. The residues detected in non-IPM samples of mango were found to be below the prescribed limits of maximum residue limit (MRL) while IPM samples were free from pesticide residues.
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