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The study evaluates the effects of seed priming (5 g or ml kg − 1 seed) and soil application (2 kg or l ha − 1 ) of eight organophosphate pesticides on rice root-knot disease caused by Meloidogyne graminicola . Seed priming (SP) or soil application (SA) of phorate, carbofuran and chlorpyriphos (1000 J 2 of M. graminicola kg − 1 soil) suppressed galling in the rice nursery by 92 and 99%, 80 and 88% and 76 and 80%, respectively, over control. Relatively similar decreases in the galling were recorded when this nursery was grown for four months in the sterilized soils in earthen pots. Rice cv. PS-5 grown in naturally infested soil in earthen pots (1000 J 2 kg − 1 soil) became stunted, showing chlorotic foliage, and terminal galls developed on the roots. The treatment of SP + SA 15 + 30 days after planting (DAP) with phorate, carbosulfan, and chlorpyriphos significantly suppressed the root-knot development and improved the plant growth of rice over the controls ( P ≤ 0.05). The overall effect of the SP + SA 15 DAP treatments was marginally weaker than the SP + SA 15 + 30 DAP treatments but statistically on par. Under field conditions, the greatest decrease in the galling occurred due to SP + SA 15 + 30 DAP of phorate (69−71%) and SP + SA 15 DAP (65−67%) followed by carbosulfan and chlorpyriphos. The yield of rice plants was also highest with phorate (32−36% and 29−34%) over the control during the two years of the study. The soil population of M. graminicola decreased by 58–84% over four months due to the phorate treatments. The study demonstrates that seed priming with phorate effectively controls nematode infections in the nursery and that soil application at 15 DAP (2 kg ai ha − 1 ) prevents root-knot development in an infested field under irrigated conditions. Use of SP + SA 15 DAP may enable to avoid one soil application of phorate in the field. [ABSTRACT FROM AUTHOR]

Abstract: The effectiveness of chlorine dioxide (CD) to remove phorate and diazinon residues on fresh lettuce and in aqueous solution was investigated. The results indicated that CD (20 mg/L) added in tap water can significantly improve the removal of phorate and diazinon on lettuce (p < 0.05), as compared to tap water wash. The study in aqueous solutions suggested that addition of CD could increase the removal rates of phorate and diazinon by 40–80% and 10–20% more than that in tap water without CD, respectively, indicating CD can result in the degradation of the both pesticides. The removal of the both pesticides in aqueous solutions was influenced by concentration of CD, pH value, treatment time, initial concentration and kind of pesticides. The degradation efficiency increased with the concentration of CD and treatment time, and the least removal rates of the both pesticides were obtained in the aqueous solution at pH 4.6. Furthermore, the lower initial concentration of pesticides, the higher degradation rate would be obtained. The degradation kinetics of both pesticides were fitted to the first-order kinetics model well, and the kinetics parameters indicated that phorate was much easier to be degraded than diazinon. The degradation products of both pesticides were identified by GC–MS, phorate and diazinon were oxidized to phorate sulfoxide and phoratoxon sulfoxide, diazoxon, respectively. The present study validates the application of CD treatment as a safe and promising method for the removal of pesticides on fresh fruits and vegetables. [Copyright &y& Elsevier]

A disordered silver nanowires membrane combining solid-phase extraction (SPE) with surface-enhanced Raman spectroscopy (SERS) was used for the rapid collection and detection of food contaminants. The membrane was fabricated via filtration of the silver nanowires colloid solution, which was prepared by a solvothermal polyol process. Analytes in 5 mL of liquid phase were concentrated in less than 10 s due to their affinity for the silver nanowires on the filter membrane. The membrane combined the advantages of SPE and SERS technology for the analysis of food safety contaminants. The use of the SERS-active extraction membrane eliminated the procedure of elution, which shortened the time of analysis. It has been shown that the as-prepared membrane had good uniformity and high temporal stability under continuous laser irradiation. Qualitative and quantitative detection of phorate and melamine was further performed based on a flow-through method. The characteristic SERS intensity plotted against phorate and melamine concentrations exhibited a good linear relationship over the concentration range of 2.5 to 10 μg mL−1 (phorate) and 2.5 to 100 μg mL−1 (melamine). [ABSTRACT FROM AUTHOR]

In vitro genotoxic effects of organophosphorus insecticides Phorate (PHR) and Trichlorfon (TCF) were investigated using four genotoxicity endpoints. Different concentration ranges between 0.25-2.00 μg mL−1 of PHR and 2.34-37.50 μg mL−1 of TCF were applied to lymphocytes. PHR and TCF significantly increased the frequency of chromosomal aberrations (except 2.34 μg mL−1 for TCF) and sister chromatid exchanges at all treatment times and concentrations. Most of the used concentrations induced a significant increase in the frequency of micronuclei. Furthermore, PHR and TCF significantly decreased the mitotic index at the higher concentrations after 24- and 48-h treatments. In the comet assay, PHR and TCF significantly increased the comet tail at all concentrations. However, the comet tail intensity was significantly increased at only the highest concentration of PHR and at all concentrations of TCF. According to these results, PHR and TCF possess clastogenic, mutagenic, and DNA damaging effects in human lymphocytes in vitro. © 2012 Wiley Periodicals, Inc. Environ Toxicol 29: 577-587, 2014. [ABSTRACT FROM AUTHOR]

Traditional pesticide residue detection methods are usually complicated, time consuming, and expensive. Rapid, portable, online, and real-time detection kits are the developing direction of pesticide testing. In this paper, we used a surface-enhanced Raman spectroscopy (SERS) technique to detect the organophosphate pesticide residue of phorate and fenthion in apple skin, for the purpose of finding a fast, simple, and convenient detection method for pesticide detection. The results showed that the characteristic wavenumbers of the two organophosphorus pesticides are more easily identified using SERS. We selected the Raman peaks at 728 cm−1of phorate and 1215 cm−1of fenthion as the target peaks for quantitative analysis, and utilized internal standards to establish linear regression models for phorate and fenthion. The detection limit was 0.05 mg/L for phorate and 0.4 mg/L for fenthion. This method can be used as a quantitative analytical reference for the detection of phorate and fenthion. [ABSTRACT FROM AUTHOR]

Susceptible discriminating doses of phorate (0.2 g/L) and sulfoxaflor (0.01 g/L) against cotton aphid Aphis gossypii Glover were determined by laboratory bioassay where aphids were sprayed with insecticide with the aid of a Potter spray tower. All of the populations tested were susceptible to sulfoxaflor, and only a pirimicarb resistant strain had cross-resistance to phorate. If phorate is used as a side dressing in Australian cotton for insect control, neither pirimicarb, or any other chemical associated with insensitive acetylcholinesterase type one resistance, should be used as the first foliar spray for any subsequent aphid control. [ABSTRACT FROM AUTHOR]

Phorate, an extremely hazardous organophosphorus insecticide, is still widely used in many countries and territories currently. It may be released in the atmosphere where it can undergo transport and chemical transformations. In this study, the reaction mechanism for the OH-initiated atmospheric oxidation of phorate was investigated. The geometrical parameters and vibrational frequencies of all the stationary points were calculated at the MPWB1K level with the 6-31G(d,p) basis set. Single-point energy calculations were carried out at the MPWB1K/6-311+G(3df,2p) level. Canonical variational transition-state theory with small curvature tunneling contribution was used to calculate the rate constants over the temperature range of 200-370 K. The Arrhenius formulas were fitted. The results indicate that the channel of the formation of phorate oxon resulting from OH addition to phorate, and H abstractions from the -CH- portion of the -CHCH group in phorate are energetically favorable. The main degradation products include phorate oxon, SO. [ABSTRACT FROM AUTHOR]

Based upon 16S rDNA sequence homology, 15 phorate-degrading bacteria isolated from sugarcane field soils by selective enrichment were identified to be different species of Bacillus, Pseudomonas, Brevibacterium, and Staphylococcus. Relative phorate degradation in a mineral salt medium containing phorate (50 μg ml) as sole carbon source established that all the bacterial species could actively degrade more than 97 % phorate during 21 days. Three of these species viz. Bacillus aerophilus strain IMBL 4.1, Brevibacterium frigoritolerans strain IMBL 2.1, and Pseudomonas fulva strain IMBL 5.1 were found to be most active phorate metabolizers, degrading more than 96 % phorate during 2 days and 100 % phorate during 13 days. Qualitative analysis of phorate residues by gas liquid chromatography revealed complete metabolization of phorate without detectable accumulation of any known phorate metabolites. Phorate degradation by these bacterial species did not follow the first-order kinetics except the P. fulva strain IMBL 5.1 with half-life period ( t½) ranging between 0.40 and 5.47 days. [ABSTRACT FROM AUTHOR]

ABSTRACT The purpose of this study was to investigate the toxic effect of long-term and low-level exposure to phorate using a metabonomics approach based on ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). Male Wistar rats were given phorate daily in drinking water at low doses of 0.05, 0.15 or 0.45 mg kg-1 body weight (BW) for 24 weeks consecutively. Rats in the control group were given an equivalent volume of drinking water. Compared with the control group, serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TBIL), urea nitrogen (BUN) and creatinine (CR) were increased in the middle- and high-dose groups whereas albumin (ALB) and cholinesterase (CHE) were decreased. Urine metabonomics profiles were analyzed by UPLC-MS. Compared with the control group, 12 metabolites were significantly changed in phorate-treated groups. In the negative mode, metabolite intensities of uric acid, suberic acid and citric acid were significantly decreased in the middle- and high-dose groups, whereas indoxyl sulfic acid (indican) and cholic acid were increased. In the positive mode, uric acid, creatinine, kynurenic acid and xanthurenic acid were significantly decreased in the middle- and high-dose groups, but 7-methylguanine (N7G) was increased. In both negative and positive modes, diethylthiophosphate (DETP) was significantly increased, which was considered as a biomarker of exposure to phorate. In conclusion, long-term and low-level exposure to phorate can cause disturbances in energy-related metabolism, liver and kidney function, the antioxidant system, and DNA damage. Moreover, more information can be provided on the evaluation of toxicity of phorate using metabonomics combined with clinical chemistry. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Studies were conducted to determine damage potential of Meloidogyne graminicola on the commonly grown rice cv. Sugandh-5 and to devise an effective management strategy. The nematicides were applied through root-dip (200 ppm solution) and soil application of 2 kg ha-1 phorate 10G (25 mg a.i./pot), carbofuran 3G (83.3 mg a.i./pot and 1 L ha-1), carbosulfan 20EC (5µL/pot) and chlorpyriphos 20 EC (6.25 µL/pot) in both nematode infested and non-infested soil with five modes of application viz., root-dip, single soil application (15 days after transplanting), root-dip + one soil application, two soil applications, and root-dip + two soil applications (15 and 30 days). Application of nematicides did not cause any toxicity symptoms on rice plants. In nematode infested soil, terminal and spiral galls developed on the rice roots, and plants suffered 20−31% decrease in the plant growth parameters. Carbofuran and phorate through root-dip plus single soil application provided greatest suppression in galling (16−20%), egg mass production (18−22%) and soil population (27.5−58.2%) of M. graminicola, and subsequently increased all the plant growth variables by 9−19%. Root-dip + two soil applications increased plant growth and suppressed nematodes, but was equal to root dip + one soil application. Root-dip treatment alone with carbosulfan also significantly suppressed root galling (10−12%) and improved the dry weight of roots and shoots (7−10%).

Beneficial soil bacteria contributes a good share in maintaining the fertility of agronomical lands naturally .This work was undertaken with the aim to isolate, identify, characterize and study growth pattern of these non targeted beneficial soil bacteria under the influence of organophosphates and Biopesticides. In this regard the morphological examination followed by biochemical characterization of isolated bacterial culture was done Further species level identification was carried out based on 16S rDNA sequence method. The results of BLAST and phylogenetic analyses revealed 1318nt and 1347nt contig region of sample F and H which were characterized as Bacillus cereus strain JY9 and Methylobacterium sp. HJM2 7 respectively, found homologous with sequence with Genbank accession no. HQ833026.1 and HM243761.1. Growth of Bacillus cereus was most adversely affected by Dimethoate followed by Phorate. The effect of Malathion and Chloripyrifos were not significant on its growth. Similarly Methylobacterium sp under the influence of Dimethoate, Chloripyriphos and Phorate showed an increased generation time whereas in presence of Malathion, it showed a normal growth curve similar to that of control. The growth pattern of both the species were not much affected by biopesticides. Our results emphasizes on less use of organophosphates in agroecosystem to reduce biotic stress on normal beneficial soil bacteria, that would ultimately be helpful in better crop yield, thereby maintaining natural ecological balance. [ABSTRACT FROM AUTHOR]

The influence of organic matter and clay contents on headspace solid phase microextraction (HS-SPME) determination of triazine and organophosphorus pesticides in different soils was studied. The results of the study showed that content of soil organic matter dominantly participated in sorption of triazines (simazine, atrazine and prometryn) to soil, while sorption of organophosphorus pesticides (phorate and tebupirimfos) could not be explained only by contents of dominant soil sorption components (soil organic matter and clay). Sorption of all pesticides studied to different soil types was similar at their lower concentrations while the influence of soil composition was expressed at higher concentration levels. Except for phorate, the obtained sorption trends were different from those obtained by direct SPME mode (DM-SPME) and exhaustive liquid-solid extraction (LSE) method. These results indicated that most likely co-extractants from the analyzed medium complicated evaporation and diffusion of the pesticides to the PDMS fiber during HS-SPME sampling. [ABSTRACT FROM AUTHOR]

Five pesticide formulations registered for use in Canada containing organophosphate-insecticide active ingredients azinphos-methyl, chlorpyrifos, diazinon, malathion and phorate were subjected to treatment by membrane bioreactor (MBR) technology. The target active ingredients were introduced to the MBR at ppm level concentrations. The biodegradation of these compounds was analyzed daily using selected ion monitoring gas chromatography−mass spectrometry (GC/MS-SIM) following extraction of the analytes using solid-phase extraction (SPE). Amounts measuring 83 % to 98 % of the target analytes were removed with steady-state concentrations being reached within 5 days of their introduction. The dissolved oxygen, temperature, pH, and total heterotrophic bacterial population were monitored daily to ensure optimal conditions for biodegradation. The quality of the effluent from the MBR was assessed daily through spectrophotometric methods. Measurements were conducted for the concentration of ammonia, nitrate, nitrite, total and reactive phosphorus, as well as the chemical oxygen demand (COD) of the effluent. This study demonstrated that the MBR technology is feasible and efficient for treatment of organophosphate pesticides without introducing additional chemical additives. [ABSTRACT FROM PUBLISHER]

Abstract: The investigation was carried out to assess the potential of bacterial isolates to degrade phorate in soil and to study the effect of presence of plants, Brassica juncea, on the biodegradation process. The bacterial consortium consisting of three isolates viz. Ralstonia eutropha, Pseudomonas aeruginosa and Enterobacter cloacae obtained by enrichment on phorate could degrade it up to 73 ± 3% in aqueous medium and 55 ± 4% in a sandy loam soil. The degradation of phorate by the consortium in the soil was increased up to 64 ± 5% in the presence of B. juncea. Biodegradation of phorate in soil in presence of plants alone was 38 ± 4% as compared to 15 ± 2% in controls. Additionally, all the three isolates were found to possess plant growth promoting potential. Thus, the isolates can be used for remediation of sites contaminated with phorate and other organophosphates. B. juncea may be a potential plant for phytoremediation and rhizoremediation of such sites. [Copyright &y& Elsevier]

Abstract: Effects of the insecticides quinalphos, chlorfenvinphos, dimethoate and phorate on photosystem activity of Chlorella vulgaris were investigated by different chlorophyll fluorescence measurements. Exposure to each of the insecticides increased the proportion of inactivated PS II reaction center. Quinalphos and chlorfenvinphos caused OJIP fluorescence reduction at all levels by decreasing the proportion of QA-reducing PS II reaction centers (RCs). The other two insecticides affected OJIP fluorescence rise by hindering the electron transport beyond QA. Insecticide treatment resulted in decrease of the density of active RC and performance indices (PI) by enhanced dissipated energy flux per active RC. Antenna size was severely minimized by quinalphos and chlorfenvinphos treatment whereas other two insecticides had no such effect. Each insecticide treatment caused increase of photosystem antenna/core and PS II/PS I fluorescence ratios. Quinalphos and chlorfenvinphos affected the donor sides of photosystems whereas dimethoate and phorate inhibited electron transfer beyond QA (acceptor side). [Copyright &y& Elsevier]

Abstract: The in vitro interaction of the organophosphorous insecticide (OPs) phorate with calf thymus DNA (ctDNA), and its potential to cause changes in cell cycle, membrane damage, and cytotoxicity leading to cell death (necrosis) was investigated in human amnion epithelial (WISH) cells. Fluorescence quenching revealed high binding affinity (K a =5.62×104 M−1) of phorate to ctDNA. Molecular modeling of the phorate–ctDNA interaction suggested the binding of phorate at AT rich regions on minor groove of DNA. The interaction ensued alkylation of the N-6, N-7 of adenine and C-4 carbonyl oxygen of thymine. Binding of phorate was stronger in the presence of the transition metal ion copper II (Cu2+), and has accentuated the destabilization of the DNA secondary structure. A discernable change in the voltammetric E 1/2 (E 0′) with lesser cathodic (i pc) and anodic (i pa) peak currents confirmed the formation of phorate–DNA and phorate–DNA–Cu (II) association complexes. Furthermore, the MTT and NRU assays demonstrated substantial phorate cytotoxicity due to loss of mitochondrial and lysosomal membrane integrity, and reduction in mitochondrial membrane potential (ΔΨm) of treated WISH cells. Cell cycle analysis of WISH cells treated with 1000μM phorate exhibited 13.7-fold (p <0.01) augmentation in the sub-G1 peak. Annexin V-PE and 7-ADD staining of phorate treated cells reaffirmed the development of late apoptotic or necrotic cell population in a concentration dependent manner. Thus, this study demonstrated the phorate induced DNA structural alterations and cellular damage in cultured human cells. [Copyright &y& Elsevier]

Studies were conducted to determine damage potential of Meloidogyne graminicola on the commonly grown rice cv. Sugandh-5 and to devise an effective management strategy. The nematicides were applied through root-dip (200 ppm solution) and soil application of 2 kg ha-1 phorate 10G (25 mg a.i./pot), carbofuran 3G (83.3 mg a.i./pot and 1 L ha-1), carbosulfan 20EC (5μL/pot) and chlorpyriphos 20 EC (6.25 μL/pot) in both nematode infested and non-infested soil with five modes of application viz., root-dip, single soil application (15 days after transplanting), root-dip + one soil application, two soil applications, and root-dip + two soil applications (15 and 30 days). Application of nematicides did not cause any toxicity symptoms on rice plants. In nematode infested soil, terminal and spiral galls developed on the rice roots, and plants suffered 20-31% decrease in the plant growth parameters. Carbofuran and phorate through root-dip plus single soil application provided greatest suppression in galling (16-20%), egg mass production (18-22%) and soil population (27.5-58.2%) of M. graminicola, and subsequently increased all the plant growth variables by 9-19%. Root-dip + two soil applications increased plant growth and suppressed nematodes, but was equal to root dip + one soil application. Root-dip treatment alone with carbosulfan also significantly suppressed root galling (10-12%) and improved the dry weight of roots and shoots (7-10%). [ABSTRACT FROM AUTHOR]

Over 5 days, Brassica juncea removed 54% of the highly toxic insecticide phorate from the medium with the formation of phorate sulfoxide in small quantity. The loss of phorate from the medium followed first-order kinetics. The half-life of phorate disappearance from water decreased by ~4.5-fold in the presence of B. juncea. Mild phorate phytotoxicity was evident from the elevated activities of the antioxidative enzymes like glutathione-disulfide reductase, glutathione S-transferase, superoxide dismutase, and catalase in the plants. Nevertheless, the ubiquitous antioxidative peroxidase was not significantly increased, nor the total glutathione content, due to phorate exposure. Phosphotriester bond hydrolysis and glutathione S-transferase-mediated conjugation seemed to be the key reactions for phorate metabolism by B. juncea. From the limited information available, for the first time, a tentative mapping of phytotransformation pathways was performed. [ABSTRACT FROM AUTHOR]

Abstract: Male Wistar rats exposed to a systemic organophosphorus insecticide, phorate [O,O-diethyl S-[(ethylthio) methyl] phosphorothioate] at varying oral doses of 0.046, 0.092 or 0.184mg phorate/kg bw for 14days, exhibited substantial oxidative stress, cellular DNA damage and activation of apoptosis-related p53, caspase 3 and 9 genes. The histopathological changes including the pyknotic nuclei, inflammatory leukocyte infiltrations, renal necrosis, and cardiac myofiber degeneration were observed in the liver, kidney and heart tissues. Biochemical analysis of catalase and glutathione revealed significantly lesser activities of antioxidative enzymes and lipid peroxidation in tissues of phorate exposed rats. Furthermore, generation of intracellular reactive oxygen species and reduced mitochondrial membrane potential in bone marrow cells confirmed phorate-induced oxidative stress. Significant DNA damage was measured through comet assay in terms of the Olive tail moment in bone marrow cells of treated animals as compared to control. Cell cycle analysis also demonstrated the G2/M arrest and appearance of a distinctive SubG1 peak, which signified induction of apoptosis. Up-regulation of tumor suppressor p53 and caspase 3 and 9 genes, determined by quantitative real-time PCR and enzyme-linked immunosorbent assay, elucidated the activation of intrinsic apoptotic pathways in response to cellular stress. Overall, the results suggest that phorate induces genetic alterations and cellular toxicity, which can adversely affect the normal cellular functioning in rats. [Copyright &y& Elsevier]

Abstract: The degradation of phorate in apple juice by sonication was investigated in the present study. Results showed that sonication was effective in eliminating phorate in apple juice, and the ultrasonic power and sonication time significantly influenced the degradation of phorate (p <0.05). The degradation of phorate followed the first-order kinetics model well. Phorate-oxon and phorate sulfoxide were identified as the degradation products of phorate by gas chromatography–mass spectrometry (GC–MS). Moreover, the toxicity of apple juice samples spiked with phorate was significantly reduced by sonication (p <0.05). The quality indexes of apple juice including pH, titratable acidity (TA), electrical conductivity (EC), total soluble solids (TSS), and the contents of sucrose, glucose and fructose were not affected by sonication, and no visible difference in color was observed between the sonicated samples and the control. [Copyright &y& Elsevier]

Organic nematicides such as neem cake, press mud, groundnut oil cake, neem mark and cotton seed oil and inorganic nematicides such as carbofuron, phorate and aldicarb have been found to have inhibitory effect against the soil nematodes including plant parasitic nematodes of sugarcane crop. The percent reductions of nematode population with the organic and chemical nematicides were studied. Among the organic amendments neem cake recorded the maximum reduction of nematode population density of 89.36 per cent and the cotton seed oil cake the minimum 60.84 per cent compared with control plots. Among the chemical nematicides, carbofuron reduced the population density of nematodes to the maximum, i.e. being 100 per cent followed by phorate while aldicarb recorded the minimum compared to the population density of control. [ABSTRACT FROM AUTHOR]

The article provides information about a study on airborne concentrations of organophosphorus pesticides among pesticide manufacturing workplaces in Korea. According to the study, pesticide manufacturing workers are primarily exposed to organophosphorus pesticides rather than farmers. The results of the study were utilized to revise the values of chlorpyrifos, parathion and phorate.

Abstract: Spotted wilt disease of peanut (Arachis hypogaea) (SWP), caused by Tomato spotted wilt virus (TSWV) (genus Tospovirus, family Bunyaviridae), was first observed in Alabama, Florida, and Georgia in the late 1980s and rapidly became a major limiting factor for peanut production in the region. Tobacco thrips (Frankliniella fusca) and western flower thrips (Frankliniella occidentalis) both occur on peanut throughout the southeastern U.S., but F. fusca is the predominant species that reproduces on peanut, and is considered to be the more important vector. Several non-crop sources of potential primary vectors and TSWV inoculum have been identified, but their relative importance has not been determined. The peanut growing season in Alabama, Florida, and Georgia is from April through November, and ‘volunteer’ peanut plants can be present for much of the remainder of the year. Therefore peanut itself has huge potential for perpetuating both vector and virus. Symptoms are often evident within a few days of seedling emergence, and disease progress is often rapid within the first 50–60 days after planting. Based on destructive sampling and assays for TSWV, there is often a high incidence of asymptomatic infections even in peanut genotypes that produce few and mild symptoms of infection in the field. Severity of SWP epidemics fluctuates significantly from year to year. The variability has not been fully explained, but lower incidences have been associated with years categorized as “La Niña” in the El Niño-Southern Oscillation. Planting date can have a large effect on disease incidence within a location. This may be linked to the thrips reproductive cycle and environmental effects on the plant and plant–thrips–virus interactions. Row pattern, plant population, and in-furrow applications of phorate insecticide can also affect epidemics of SWP. Considerable progress has been made in developing cultivars with natural field resistance to TSWV. Use of cultivars with moderate field resistance combined with other suppressive measures has been very successful for managing spotted wilt disease. Several new cultivars with higher levels of field resistance can improve control and allow more flexibility in the integrated management programme. Although effects of these factors on epidemics of SWP have been documented, mechanisms responsible for disease suppression by most factors have not been fully elucidated. [Copyright &y& Elsevier]

Abstract: Phorate, an organophosphorus insecticide is known for its adverse effects on acetylcholinesterase, and other neuronal and pulmonary activities. Most likely, the toxicity of drugs/agrochemicals is modulated through cellular distribution bound to plasma proteins. Therefore, the in vitro interaction of phorate with human serum albumin (HSA) has been investigated, using sensitive techniques like fluorescence spectroscopy and circular dichroism, to ascertain its binding mechanism and toxicological implications. Fluorescence studies revealed the quenching constant (Ksv) as 2.5×104 M−1 and binding affinity (Ka) as 2.96×104 M−1 (r 2 =0.99), with a primary binding site of phorate at sub-domain IIA of HSA. Circular dichroism (CD) data demonstrated a noticeable reduction in secondary structure (α-helical content) of phorate treated HSA. Albumin treated with 200–1000μM phorate released significant amounts of acid soluble amino and carbonyl groups, whereas higher concentrations resulted in protein fragmentation. It is postulated that the 1′-O and 3-O alkyl groups of phorate have a role in binding with electrophilic centers of Trp 214, and Arg 218/Lys 195, respectively. Moreover, the significant ultrastructural changes, reactive oxygen species (ROS) generation, mitochondrial damage and cell death in phorate treated cultured human amnion epithelial (WISH) cells, elucidated phorate induced cellular toxicity. [Copyright &y& Elsevier]

The effects of Pseudomonas fl uorescens and Trichoderma harzianum, on the control of the rootknot nematode, Meloidogyne incognita, were investigated in three tobacco cultivars (RK-18 P8, RK-26 P3 and RK-12 P3). Soil application of the biocontrol agents was compared with two nematicides, Phorate and Furadan. Greatest reduction in the numbers of second-stage juveniles in soil, host root galls and egg mass indices were recorded with Furadan and P. fluorescens compared with experimental controls. The greatest increase in the plant growth and biomass of tobacco was obtained in cv. RK-18 P8 with P. fluorescens (16- 32%) followed by Furadan (15-30 %) compared with experimental controls. Increases in total phenol (TP) and salicylic acid (SA) were negatively correlated with numbers of root galls and egg masses/root system. Greatest increases in the leaf contents of SA (20%) and TP (31%) were recorded in cv. RK-12 P3, whereas least increases were detected in cv. RK-18 P8 (17% TP and 10% SA). The study has revealed that cv. RK-12 P3 may be exploited commercially for nematode resistance to M. incognita, and P. fluorescens may be used as an alternative to nematicides in nematode infested field, to obtain higher productivity of tobacco [ABSTRACT FROM AUTHOR]

India, with its huge human population and fragmented wildlife habitat, is plagued with human-animal conflicts. In conflict areas, large carnivores are often primary targets for malicious poisoning. The effects of certain poisons do not stop with the target animal but also affects other species of wildlife in the form of secondary poisoning. This paper describes incidences of secondary poisoning of a tiger ( Panthera tigris) and a black panther (melanistic Panthera pardus) in the Nilgiri Biosphere Reserve. Wild boars ( Sus scrofa), which are considered pests in horticultural plantations, were the primary targets in both cases and were poisoned using phorate, a highly toxic organophosphorus compound. Tigers and leopards hold significant position in the upper most trophic level of the ecological pyramid and are grouped in schedule I of the Wildlife Protection Act of India. The tiger, as a species, is currently waging a grim battle of survival in the wild. The world over, leopard populations are also dwindling. The implications of the death of these endangered apex predators due to the increase in population of the ubiquitous wild boars are analysed. The merits of introducing a policy of selective culling of wild boars in conflict areas are discussed. [ABSTRACT FROM AUTHOR]

Abstract: The photocatalytic degradation of phorate in aqueous suspensions was examined with the use of titanium dioxide (TiO2) as a photocatalyst. About 99% of phorate was degraded after UV irradiation for 60min. The photodegradation of phorate followed pseudo-first-order kinetics and parameters such as pH of the system, TiO2 dosage, and presence of anions were found to influence the reaction rate. To obtain a better understanding of the mechanistic details of this TiO2-assisted photodegradation of phorate with UV irradiation, the intermediates of the processes were separated, identified, and characterized by the solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS) techniques. The probable photodegradation pathways were proposed and discussed. To the best of our knowledge, this is the first study that reports the degradation pathways of phorate. The electrical energy consumption per order of magnitude for photocatalytic degradation of phorate was also calculated and showed that a moderated efficiency (E EO =96kWh/(m3 order)) was obtained in TiO2/UV process. [Copyright &y& Elsevier]

Wireworms (larval Elateridae) are perennial pests of newly planted sugarcane causing stand loss directly by damaging growing points and indirectly by introducing disease. Two organophosphate insecticides, phorate and ethoprop, are currently labeled for controlling wireworms in sugar cane. In the first experiment, 4 rates of phorate (100, 87.5, 75, and 62.5% of the current maximum field rate) were used in 2 different types of soil: Dania Muck and Immokalee Fine Sand. In the second experiment, 4 rates of phorate and ethoprop (100, 75, 50, and 25% of current maximum field rates) were used in a Lauderhill Muck soil. A notreatment and a wireworm-free treatment were used as controls in both experiments. The effect of the insecticide was evaluated in simulated field experiments conducted in 18.9-L (5- gallon) buckets filled with soil and artificially infested with 10 wireworms ( Melanotus communis (Gyllenhall), Coleoptera: Elateridae) per bucket. After 60 d, the contents of the buckets were emptied to evaluate damage to the plant and count the surviving wireworms. Insecticides resulted in fewer live wireworms and reduced damage to sugarcane shoots, roots, and seed pieces compared to the no-treatment control. In the first experiment, phorate proved to be very effective at controlling wireworms even at the 62.5% rate. Phorate was more effective in the Immokalee Fine Sand than in the Dania Muck. In the second experiment, phorate was found to be more effective at reducing stand loss and wireworm numbers than ethoprop. [ABSTRACT FROM AUTHOR]

Abstract: The effects of an organophosphate pesticide phorate on cytoplasmic malate dehydrogenase (cMDH), mitochondrial malate dehydrogenase (mMDH), lactate dehydrogenase (LDH), supernatant and mitochondrial proteins of an epigeic (Perionyx sansibaricus), anecic (Lampito mauritii) and endogeic (Metaphire posthuma) earthworms were studied. The treatment of different concentrations (20, 40, 80 and 160ppm) of phorate for 16days gradually decreased the specific activities of cMDH, mMDH and LDH as well as cytoplasmic and mitochondrial protein contents. This showed the inhibitory effect of phorate on metabolic enzymes and proteins in tropical earthworms. The inhibition was dose- and time-dependent. The inhibitory response in mitochondrial enzyme (mMDH) and protein was somewhat earlier and more as compared to the inhibitory effect of phorate on cytoplasmic enzymes (cMDH, LDH) and protein. This indicates a greater interference of phorate in cellular respiration of earthworms. The phorate related decreases in enzyme and protein profiles were about 60% and 58% in P. sansibaricus, 54% and 49% in L. mauritii and 47% and 42% in M. posthuma, respectively. It reflects phorate-induced substantial decline in protein synthesis and aerobic and anaerobic capacity of earthworms. The maximum effect of phorate was on epigeic earthworm followed by anecic and endogeic species. The present findings suggest the differential sensitivity of different earthworm species in enzymatic and protein responses to phorate and the sensitivity was associated with the ecophysiological categories of earthworms. [Copyright &y& Elsevier]

Aims: To study the degradation of phorate by a bacterium isolated from phorate-contaminated sites. Methods and Results: Ralstonia eutropha strain AAJ1 isolated from soil was found to degrade phorate (supplied as sole carbon source) upto 85% in 10 days in liquid medium. Half-life ( t½) of phorate in the liquid medium in control (uninoculated) and in experimental (inoculated with R. eutropha, strain AAJ1) samples was recorded as 36·49 and 6·29 days, respectively. Kinetics revealed that phorate degradation depends on time and the reaction follows the first order kinetics. Diethyl dithiophosphate was one of the degradation products, which is markedly less toxic than the parent compound; other degradation products included phorate sulfoxide and phorate sulfone. Release of inorganic phosphates and sulfates indicated the potential of the isolate to further degrade the above-mentioned metabolites to simpler forms. The strain was also found to posses phosphomonoesterase and phosphodiesterase enzymatic activity, which are involved in biodegradation of organophosphorus compounds. Conclusions: Ralstonia eutropha AAJ1 could degrade and detoxify phorate upto 85% in 10 days in laboratory conditions. Significance and Impact of the Study: The isolate has the potential to be utilized for remediation of phorate-contaminated water and soil. [ABSTRACT FROM AUTHOR]

The degradation of 15 organophosphorus insecticides was studied in drinking, ground, and surface waters under different laboratory-controlled and environmental conditions. Surface waters originated from rivers Savinja (near the city of Celje) and Kamniska Bistrica (at the spring), which both belong to the Danube river basin. Groundwater was collected from wells (70 m deep) in Ljubljana, which are the direct source of drinking water for the capital. These matrices were selected on the basis of their different chemical composition and microbial activity. Major factors influencing the degradation were determined, such as temperature, oxygen, sunlight, pH, and type of water. The degradation of atrazine, present in many water sources in Slovenija, was followed simultaneously as a reference under the same conditions. The degradation kinetics was followed by gas chromatography with mass-selective detection, which also allowed the identification of some degradation by-products, such as oxon analogues paraoxon, dyfoxon, malaoxon, phenyl-methyl sulfoxide, fenthion sulfone, phorate sulfoxide, and phorate sulfone. The results show that the half-lives of the selected organophosphorus insecticides varied from 4 to 192 days or more, depending on the water source and experimental conditions. As a result, kinetically constants and half-lives were calculated for every tested insecticide, and major degradation products were determined. [ABSTRACT FROM AUTHOR]

Phorate (O,O-diethyl S-ethylthiomethyl phosphorodithioate) dissolved in aqueous solution was almost completely decomposed by ozonation to form various species within 10 minutes of reaction time for the experimental conditions examined in this research. The generation rate of sulfate was found to be fairly independent of solution pH value. However, the formation of phosphate and carbonate was more favorable for alkaline solutions where hydroxyl free radical is the primary oxidative species. The reaction rates increased with initial gaseous ozone concentrations, indicating the reaction was mass transfer-controlled within the experimental range of this research. Combining the analytical results by various instruments, including gas chromatograph equipped with an electron ionization detector (GC-EID), high performance liquid chromatography (HPLC), ion chromatography (IC), and total organic carbon (TOC), the temporal sequence of phorate ozonation was proposed in this study. The oxidation of sulfur atoms on the phosphorus-sulfur double bond or carbon-sulfur-carbon bond by ozonation was found to occur at first to form sulfate and various intermediates. [ABSTRACT FROM AUTHOR]