Market basket monitoring of some organophosphorus pesticides on apple and strawberry in Izmir Province, Turkey

WOS: 000182422500004Organophosphorus (OP) insecticides are widely used in fruits and vegetables in Turkey. Levels of OP-insecticides residues were investigated on apple and strawberry samples, 32 for each, in Izmir to check for compliance with Maximum Residue Levels (MRLs) and to assess the pesticide exposure of the people in Izmir. This study was conducted at University of Ege, Agriculture Faculty, in collaboration with Drug Research Developing and Pharmacokinetics Research Center between 1999-2001. Residues of azinphos-methyl, chlorpyriphosethyl, diazinon, dichlorvos, malathion, methidathion and parathionmethyl were extracted from samples according to DFG (Deutschen Forschungsgemeinschaft) S19 multiresidue method. For the determination of OP-insecticides multiresidue analysis method with GC/NPD detector was used. The findings for apple demonstrated that OP-insecticides residues are generally below codex tolerances. Residues of OP-insecticides were detected in 13 out of 32 apple samples analysed in this study. In 1 sample malathion, in 2 samples azinphos-methyl and methidathion, and in 3 samples chlorpyrifos-ethyl were detected exceeding their respective tolerance levels. Residues of OP-insecticides were detected in 23 out of 32 strawberry samples. Diazinon and methidathion residues were detected only in 1 sample each, but the values exceeded the tolerance limit. In 5 samples parathion and in 3 samples chlorpyrifos-ethyl were detected over their tolerance levels. Out of 32 samples, 21 were found to contain residues of dichlorvos and 15 of them exceeded the MRL. Importantly, some contaminated samples were found to contain dichlorvos residues 10-77 times higher than the MRL

Landfill settlement with decomposition and gas generation

A one-dimensional multiphase numerical model is developed to simulate the vertical settlement involving liquid and gas flows in a deformable.(settling) municipal solid waste (MSW) landfill. MSW is represented by a chemical composition, and a global stoichiometric reaction is used to estimate the maximum yield of gas generation. Following the general assumption accepted in the literature, the gas generated by waste decomposition is assumed to comprise of in I ethane (CH4)and carbon dioxide (CO2). The gas generation rate follows an exponentially decaying function of time. The gas generation model developed based on a first-order kinetic single-bioreactor approach includes the governing equations of gas migration, liquid flow, and landfill deformation. The. Galerkin finite element method is used to solve the resulting equations. The model developed can be used to estimate the transient and ultimate settlements due to waste decomposition and gas generation in MSW landfills. The proposed model can estimate the waste porosity, gas pressure, liquid pressure, gas saturation, liquid saturation, and stress distributions in settling landfills. The results obtained for a deformable landfill are compared with a landfill having a rigid solid skeleton. Due to settlement, the depth of waste is 27% smaller in deformable landfills than that of the rigid ones

Modeling of landfill settlement: Theory

Theory of a one-dimensional multiphase mathematical model developed to simulate the settlement involving liquid and gas flows in a compressible landfill is presented. Landfill domain is assumed comprised of a deformable solid matrix, a liquid phase, and a gas phase with transient gas generation. After a two-phase model, i.e., liquid and gas phase, was developed, a solid phase was incorporated into the model. A gas generation term was employed as source and sink for solid and gas phases. After governing equations are developed, the Galerkin finite element technique is employed to discretize the partial differential equations

Active ingredient contents of 'me-too' registered abamectin products and differences in their efficacy on Tetranychus cinnabarinus

Many agrochemical companies in Turkey purchase generic active ingredients (a.i.) and, by way of 'me-too' registration, sell pesticides under different brand names. Farmers and researchers often claim that these products are ineffective. In order to determine the a.i. content and efficacy of me-too registered abamectin-based products, we studied seven (in 2004) and ten (in 2005) products, which were chosen based on their availability and high market share. Differences in both efficacy and a.i. contents were observed in the products investigated in the study, but making speculative statements that could affect all me-too registered products based on our investigations of only 17 abamectin-based samples is not realistic. Timectin® was found to be statistically less effective on Tetranychus cinnabarinus in both laboratory and greenhouse trials than all other tested products. Furthermore, Timectin was determined to have 69.8% less a.i. than in its product specifications. Our findings make it clear that grower complaints about the qualities of agricultural pesticides are based on actual chemical inadequacies of formulated pesticides. Analysis of the a.i. should be carried out as part of regular market inspection in order to determine whether agricultural pesticides comply with their product specifications. In this way growers will be provided with good quality but inexpensive products.Firat University Scientific Research Projects Management UnitWe would like to thank Syngenta, Turkey, for providing the abamectin standard; EBILTEM for providing HPLC to be used in analysis; and Ege University Scientific Research Projects Commission for the financial support they provided for the study. -

Effects of two different neem products on different states of Nezara viridula (L.) (heteroptera, pentatomidae)

In this study, the effects of two different commercial neem insecticides (NeemAzal T/S and Neem Oil) were determined on different stages of Nezara viridula (L.) (Heteroptera: Pentatomidae) under laboratory conditions. Neem Azal and Neem Oil were applied at concentrations of 0.5 % and 2 %, respectively. Mortality was recorded after 3, 7 and 14 days for nymphs and adults; 7 and 14 days for old (4-day-old) eggs; and 14 days for newly laid (one-day-old) eggs. Both products have no significant effect on adults and newly laid eggs. However Neem Oil was found to be more effective than NeemAzal T/S on nymphs and on old laid eggs after 7 and 14 days. It can be concluded that both neem products have potential for insecticidal efficacy (approximately 60 %) against nymphs of N. viridula. at concentrations recommended by manufacturers for registered pests