Dissipation of spiromesifen and spiromesifen-enol on tomato fruit,tomato leaf,and soil under field and controlled environmental conditions

Dissipation of spiromesifen and its metabolite, spiromesifen-enol, on tomato fruit, tomato leaf, and soil was studied in the open field and controlled environmental conditions. Sample preparation was carried out by QuEChERS method and analysis using LC-MS/MS. Method validation for analysis of the compounds was carried out as per “single laboratory method validation guidelines.” Method validation studies gave satisfactory recoveries for spiromesifen and spiromesifen-enol (71.59–105.3%) with relative standard deviation (RSD) < 20%. LOD and LOQ of the method were 0.0015 μg mL^?1 and 0.005 mg kg^?1, respectively. Spiromesifen residues on tomato fruits were 0.855 and 1.545 mg kg^?1 in open field and 0.976 and 1.670 mg kg^?1 under polyhouse condition, from treatments at the standard and double doses of 125 and 250 g a.i. ha^?1, respectively. On tomato leaves, the residues were 5.64 and 8.226 mg kg^?1 in open field and 6.874 and 10.187 mg kg^?1 in the polyhouse. In soil, the residues were 0.532 and 1.032 mg kg^?1 and 0.486 and 0.925 mg kg^?1 under open field and polyhouse conditions, respectively. The half-life of degradation of spiromesifen on tomato fruit was 6–6.5 days in the open field and 8.1–9.3 days in the polyhouse. On tomato leaves, it was 7–7.6 and 17.6–18.4 days and in soil 5.6–7.4 and 8.4–9.5 days, respectively. Metabolite, spiromesifen-enol, was not detected in any of the sample throughout the study period. Photodegradation could be the major route for dissipation of spiromesifen in the tomato leaves, whereas in the fruits, it may be the combination of photodegradation and dilution due to fruit growth. The results of the study can be utilized for application of spiromesifen in plant protection of tomato crop under protected environmental conditions.     

Dissipation behavior of propargite--an acaricide residues in soil, apple (Malus pumila) and tea (Camellia sinensis)

Propargite, recently introduced in India, is an effective acaricide on a large number of crops most of which are consumed by human beings directly or after processing. Therefore, it has become important to check the dissipation behavior of propargite in edible raw commodities, processed products and in the environment. In the present study, dissipation of residue of this acaricide in soil, apple fruit and tea (green tea leaves, manufactured tea, infusion and spent leaves) was studied. Analysis was carried out using high performance-liquid chromatography with UV detection system. The dissipation rate was found to vary with the nature of studied crop/sample. In soil, half-life ranged from 43 to 45 days, while in plant matrices (tea and apple) it ranged 1.66-2.61 days. The percent transfer of propargite residue from manufactured tea to infusion was 23.60-40.00; however, 35.71-53.20% of the residues remained stuck to the spent leaves.     

Phytotoxicity to and uptake of enrofloxacin in crop plants

Phytotoxicity of enrofloxacin on crop plants Cucumis sativus, Lactuca sativa, Phaseolus vulgaris and Raphanus sativus was determined in a laboratory model: the effect of 50, 100 and 5000 microgl(-1) were evaluated after 30 days exposure by measuring post-germinative growth of primary root, hypocotyl, cotyledons and leaves. Concentrations between 50 and 5000 microgl(-1) induced both toxic effect and hormesis in plants, by significantly modifying both length of primary root, hypocotyl, cotyledons and the number/length of leaves. A toxic effect is induced by high concentration (5000 microgl(-1)), while hormesis occurs at low concentrations (50 and 100 microgl(-1)). A continuum between toxic effect and hormesis is found in the four plant species. Both toxic effect and hormesis can be related to an efficient plant drug uptake, in the order of microgg(-1). Plants are able to metabolize enrofloxacin into ciprofloxacin, as also happens in animals; Cucumis, Lactuca and Phaseolus biologically convert about one quarter of stored enrofloxacin. The ecological implication of enrofloxacin contamination in terrestrial environments is discussed.     

Residues of dioxins (PCDD/Fs) and PCBs in eggs, fat and livers of laying hens following consumption of contaminated feed

Laying hens were fed with feed from the Belgian dioxin incident diluted ten-fold with non-contaminated feed, resulting in concentrations of 61 ngTEQkg(-1) PCDD/Fs, 23 ngTEQkg(-1) non-ortho PCBs, 116 ngTEQkg(-1) mono-ortho PCBs and 3.2 mgkg(-1) of the seven indicator PCBs. Following exposure for seven days, feed was replaced by non-contaminated feed for a period up to six weeks. Concentrations of PCDD/Fs in eggs showed a maximum of 214 pgTEQg(-1) fat after nine days and decreased to 44 pgTEQg(-1) after seven weeks. Dioxin concentrations in abdominal fat of chickens killed just after the last treatment, or after 1, 3 or 6 weeks on clean feed were 69, 84, 54 and 41 pgTEQg(-1) fat, respectively. Concentrations in livers decreased more rapidly, being 35, 7, 4 and 3 pgTEQg(-1) tissue, respectively. In both eggs and tissues, total TEQ concentrations were 3-4 times higher. Concentrations of the seven indicator PCBs in egg fat showed a stronger decrease with concentrations of 16.5 microgg(-1) at the peak (day 9) and 2.2 microgg(-1) after seven weeks. Corresponding concentrations in abdominal fat were, respectively, 4.6 and 2.6 microgg(-1) fat, and in livers 0.77 and 0.14 microgg(-1) tissue. The ratio of indicator PCBs to PCDD/Fs in feed was 52200. In eggs this ratio was initially higher (85000), but decreased towards 50000 after six weeks on clean feed. In abdominal fat the ratio varied between 49000 and 67000. In livers, the ratio was initially low (22000) but increased to 45000 towards the end of the study. It is concluded that the behaviour of PCDD/Fs and PCBs in laying hens is comparable and that the use of indicator PCBs appears to be a good alternative for PCDD/Fs but only in the case of co-exposure to both PCBs and PCDD/Fs, such as in incidents with PCB oil.     

Uptake and translocation of metals in Spinacia oleracea L. grown on tannery sludge-amended and contaminated soils: effect on lipid peroxidation, morpho-anatomical changes and antioxidants

The plants of Spinacia oleracea L. grown on contaminated soil (CS) and different amendments of tannery sludge (TS) have shown high accumulation of metals in its edible part. The accumulation of toxic metal (Cr) in the leaves of the plants grown on CS was recorded as 40.67 microgg(-1)dw. However, the leaves of the plants grown on 100% TS have accumulated about two times (70.80 microgg(-1)dw) higher Cr than the 10% TS (31.21 microgg(-1)dw). Among growth parameters, the root length was more affected at 90 d than the shoot length, number of leaves and leaf area. The study of scanning electron micrographs showed 29.31% increase in stomatal length in the leaves of the plants grown on CS as compared to garden soil (GS), which served as control, however it decreased in the plants grown on higher amendments of TS. The decrease in MDA content at initial period of exposure and lower amendment was recorded in the leaves, whereas, significant increase (>10% TS onward) was observed with increase in tannery sludge ratio at 90 d as compared to GS. A coordinated increase in all the studied antioxidants (cysteine, non-protein thiol, ascorbic acid, carotenoid contents) was found up to 75 d of growth. At 90 d, most of the antioxidant decreased as compared to 75 d causing oxidative stress as evidenced by increased level of lipid peroxidation and decreased chlorophyll and protein contents. Maximum increase of 181.43% in MDA content and maximum decrease of 53.69% in total chlorophyll content was recorded in the leaves of the plants grown on 100% TS after 90 d of growth. The plants grown on CS have shown an increase in shoot length, number of leaves, leaf area, photosynthetic pigments and protein contents and in all the studied antioxidants. Thus, these plants are able to combat stress involving defense mechanism, resulting in healthy growth of the plants. The results are well coordinated as there is no change in the MDA content as compared to the plants grown on GS. In view of high Cr accumulation in edible part of S. oleracea grown on CS after irrigation with tap water, it is not advisable to use these plants for edible purposes. Summing up, it is recommended that the level of metals in the edible part should be checked instead of healthy growth as deciding parameter for consumption. It is demonstrated through this study that metal enriched plants have detoxification mechanism and grow well on organic matter enriched contaminated soil.     

Dissipation of 14C carbaryl and quinalphos in soil under a groundnut crop (Arachis hypogaea L.) in semi-arid India

The dissipation of 14C carbaryl in undisturbed soil cores, and of quinalphos (25EC and 20AF) after seed and soil treatments, was investigated under field use conditions, in a semi-arid groundnut field. Residues were analyzed by TLC and HPLC and additionally by LSC for 14C carbaryl. The harvested seed kernels were also tested for the presence of insecticide residues. The movement of carbaryl was limited to 15 cm depth in the loamy sand of Jaipur and was detected till 120 days (DT50 of 14.93 days) after application. Bound residues and 1-naphthol had a DT50 of 11.45 and 13.68 days, respectively. Irrespective of the three types of soil samples investigated, the principal metabolite formed on seed and soil treatments with quinalphos, was 2-hydroxyquinoxaline. With seed treatment, a thiol metabolite of quinalphos was also detected. Higher yields of groundnut were realized with quinalphos treatments in comparison to those from control. Post-harvest, no pesticide residues were found in seeds.     

Dissipation of sulfosulfuron in water - bioaccumulation of residues in fish - LC-MS/MS-ESI identification and quantification of metabolites

Dissipation study of sulfosulfuron in natural water and its bioaccumulation in fish was conducted at 25+/-2 degrees C and at two different concentration levels 1mgl(-1) and 2mgl(-1). The dissipation data in water showed the DT50 and DT90 values 67-76 and 222-253 days and followed first order kinetics. Bioaccumulation of sulfosulfuron in fish was conducted under static conditions exposing the fish at one-tenth of sub-lethal concentration 9mgl(-1) and at double the concentration 18mgl(-1), for a period of 56 days. On different occasions fish samples were collected and analyzed. A HPLC-RF method was used for the quantification of sulfosulfuron and aminopyrimidine with the limit of quantification 0.001microg ml(-1). Results showed the accumulation of residues of sulfosulfuron in fish over the concentration range 0.009-0.496microg g(-1). Both in water and fish samples, identified the presence of metabolites aminopyrimidine, desmethyl sulfosulfuron, guanidine, sulfonamide, ethyl sulfone and rearranged amine. The formations of these metabolites are confirmed by LC-MS/MS analysis. An LC-MS/MS electro spray ionization technique was used for this purpose. One of the metabolite Aminopyrimidine was identified at higher concentration levels (0.01-0.1microg ml(-1)) when compared with other metabolites. Subsequently dissipation of aminopyrimidine in water and its bioaccumulation was also studied at the concentration level 1mgl(-1) and 2mgl(-1). The calculated DT50 and DT90 values are 66-68 days and 218-226 days, respectively. This followed first order kinetics. Three hundred days after the exposure complete demineralization was observed.     

Assessment of imidacloprid in Brassica environment

Imidacloprid was applied as seed treatment (Gaucho 70 WS, 5 and 10 g ai kg(-1) seed) and foliar spray (Confidor 200 SL, 20 and 40 g ai ha(-1)) at 50% pod formation stage on mustard (Brassica campestris Linn.) to control mustard aphid, Lipaphis erysimi Kalt. It was detectable upto 82 and 96 days in plants after sowing from lower and higher doses of seed treatment. However, it dissipated faster and became nondetectable after 7 and 15 days of foliar treatments from lower and higher rates of application, respectively. The dissipation models yielded the rate constants of 0.0209 and 0.0230 and 0.0736 and 0.0779 day(-1) from seed and foliar treatment. The corresponding half-lives of 14.40 and 13.07 and 4.09 and 3.86 days were recorded. This suggested that the dissipation was independent of initial doses and followed a first order rate kinetics. The projected TMRC of imidacloprid from seed (0.136 and 0.225 mg person(-1) day(-1)) and foliar (0.069 and 0.1497 mg person(-1) day(-1)) treatments were found lower than the MPI (3.135 mg person(-1) day(-1)). At harvest mustard grains did not contain imidacloprid residues. The absence of imidacloprid in 0-10 and 10-20 cm soil layers indicated no leaching of insecticide. Therefore, imidacloprid treatments could be taken as safe for crop protection, consumption of leaves and environmental contamination point of view.     

Dissipation and leaching of (14)C-monocrotophos in Soil Columns under subtropical climate

Dissipation and leaching behavior of 14C-monocrotophos was studied for 365 days under field conditions using PVC cylinders. The first set (24 cylinders) was spiked with 1.0 microCi 14C-labeled monocrotophos along with 1.06 mg unlabeled monocrotophos to give a concentration of 2 mg kg -1 in the soil up to 15 cm depth. The second set (24 cylinders) received 14C-labeled monocrotophos along with other non-labeled insecticides viz., dimethoate @ 300 g a.i ha-1, deltamethrin @ 12.5 g a.i ha-1, endosulfan @ 750 g a.i ha-1, cypermethrin @ 60 g a.i ha-1, and triazophos @ 600 g a.i ha-1 at an interval of 15 days each as recommended for the cotton crop. 14C-monocrotophos dissipated faster, up to 45% in first 90 days in columns treated with only monocrotophos compared to 25% in columns that received monocrotophos along with other insecticides. However, both the columns showed similar residues 180 days onward. After 180 days of treatment, 46% radiolabeled residues were observed, which reduced up to 39.6% after 365 days. Leaching of 14C-monocrotophos to 15-30 cm soil layer was observed in both the experimental setups. In the 15-30 cm soil layer of both soil columns, up to 0.19 mg 14C-monocrotophos kg-1d. wt. soil was detected after 270 days.     

Studies on the residues of phosalone on chilli by GLC after multiband plate cleanup

Abstract

Four sprays of 0.05 ana 0.10% phosalone were given on chilli (Capsicum annuum Linn.) crop at an interval of 15 days starting from 21 days after transplanting. Residues were determined in the green chilli fruits by GLC after cleanup of extract on multiband thin‐layer plate. The half‐lives of residues were 1.55 and 1.68 days on chilli fruits from the crop treated with four sprays of 0.05 and 0.10% phosalone respectively. The time required to reach the tolerance limit of 1 ppm after last spray with 0.05 and 0.10 % emulsion was 4.75 and 7.62 days respectively. Washing of fruits under tap water was found effective in bringing down the level of phosalone residues by 21.64 to 75.11 %.     

Behaviour of forchlorfenuron residues in grape,soil and water

Persistence of forchlorfenuron residues in grape berries at harvest following its dip application as single or split doses to grape berry clusters and periodic dissipation of forchlorfenuron residues in grape berries following foliar spray application were studied. Periodic dissipation of forchlorfenuron residues following its fortification in soil and water were also studied. Splitting the dip application concentration of forchlorfenuron to grape berries reduced its residues in the berries at harvest, which persisted for more than 65 days from all treatments. In case of foliar application, however, the residues of forchlorfenuron in/on the grape berries persisted for 15-20 days only from three treatment concentrations of 2, 3 and 4 ml/l and dissipated with half-lives of 3.4-4.5 days. The residues of forchlorfenuron dissipated faster in soils maintained at field capacity moisture condition than in air dry soils. There was wide variation in its residue persistence in soil (DT50 = 15.1-121.3 days) depending on soil type and moisture condition. Forchlorfenuron residues persisted for more than 30 days in water and its dissipation was fastest at a water salinity level of 3.85 mmho/ cm although the rate of dissipation was not significantly affected by the change in salinity level from <0.04 to 5.90 mmho/cm.     

Total and subcellular distribution of trace elements (Cd, Cu and Zn) in the liver and kidney of green turtles (Chelonia mydas) from the Mediterranean Sea

This study investigated the subcellular distribution of Cd, Cu and Zn in liver and kidney of green turtles (Chelonia mydas) stranded along the Italian coast of the South Adriatic Sea (Eastern Mediterranean). Cd and Zn mean concentrations did not differ significantly between liver (4.26microgg(-1) and 34.53microgg(-1), respectively) and kidney (5.06microgg(-1) and 26.39microgg(-1), respectively), whereas the levels of Cu were significantly higher in liver (32.75microgg(-1)) than in kidney (8.20microgg(-1)) (p<0.009). Most of Cd, Cu and Zn was present in hepatic and renal cytosol, and their concentrations increased with total levels in both organs, indicating that cytosol has a crucial role in metal accumulation. Cd and Cu in hepatic and renal cytosol were present mostly in metallothionein fractions (MTs), whereas Zn was fractionated into MTs and high-molecular-weight-substances (HMWS). The comparison with the results of other investigations on individuals of the same species collected in different marine areas shows good agreement relatively to essential metals. For Cd our data are comparable with those encountered in specimens from the Mediterranean Sea (Cyprus) confirming the homogeneity of the area comprising the south-eastern basin of the Mediterranean Sea from an ecological point of view.     

Bioefficacy of iprodione against two desapers, its compatibility with T. harzianum and residues on cabbage crop

Iprodione (3-(3,5-dichlorophenyl)-N-isopropyl-2,4-dioxoimidazolidine-1-carboxamide) bio-assayed against fungi Alternaria brassicicola and Sclerotinia sclerotiorum was found to be highly effective for inhibiting these desapers. Inhibition of A. brassicicola was 100% up to the dose of 75 ppm and for S. sclerotiorum there was 50% inhibition for the same concentration. Formulation of the pesticide was applied @ 500 and 1000 g. a.i./ha on the cabbage crop grown in the fields. Residues in the edible sample of cabbage were analyzed by gas choromatography for the fungicide and its metabolites. The dissipation of residues of the fungicide and its bio-efficacy against two fungi are presented. It dissipated from 3.72 to 0.072 microg/g on cabbage head by 15 days after treatment. The EC50 values of iprodione were found to be 11.5 ppm and 79.4 ppm for A. brassicicola and S. sclerotiorum, respectively. Half-life of iprodione was found to be 3 days for both cabbage head and leaves. The compatibility of the fungicide with a bio agent, T. harzianum was also studied and these two were not found to be compatible.     

Influence of crop residues on trifluralin mineralization in a silty clay loam soil

Trifluralin is typically applied onto crop residues (trash, stubble) at the soil surface, or onto the bare soil surface after the incorporation of crop residues into the soil. The objective of this study was to quantify the effect of the type and amount of crop residues in soil on trifluralin mineralization in a Wellwood silty clay loam soil. Leaves and stubble of Potato (Solanum tuberosum) (P); Canola (Brassica napus) (C), Wheat (Triticum aestivum) (W), Oats (Avena sativa), (O), and Alfalfa (Medicago sativa) (A) were added to soil microcosms at rates of 2%, 4%, 8% and 16% of the total soil weight (25 g). The type and amount of crop residues in soil had little influence on the trifluralin first-order mineralization rate constant, which ranged from 3.57E-03 day(-1) in soil with 16% A to 2.89E-02 day(-1) in soil with 8% W. The cumulative trifluralin mineralization at 113 days ranged from 1.15% in soil with 16% P to 3.21% in soil with 4% C, again demonstrating that the observed differences across the treatments are not of agronomic or environmental importance.     

Nitrate reductase, arginine deaminase, urease and dehydrogenase activities in natural soil (ridges with forest) and in cotton soil after acetamiprid treatments

Soil enzymes are indicators of microbial activities in soil and are often considered as an indicator of soil health and fertility. They are very sensitive to the agricultural practices, pH of the soil, nutrients, inhibitors and weather conditions. To understand the effect of an insecticide, acetamiprid (IUPAC Name: (E)-N1-[(6-chloro-3-pyridyl) methyl]-N2-cyano-N1-methyl acetamidine) on different soil enzyme activities, the experiments were conducted for three consecutive years (2003--2005) at control and cotton experimental fields of Indian Agricultural Research Institute (IARI) and natural area (ridges with forest) in Delhi. The combined results for all three years were presented here to understand the impact of acetamiprid on soil enzyme activities. Acetamiprid was applied three times in one crop season after 41, 48 and 73 days of sowing, to control the pest. Soil of treated fields was analyzed for insecticide residues immediately after first insecticide treatment and thereafter at definite period. The residues of acetamiprid in experimental soil was varied from 0.30+/-0.13 to 22.67+/-0.2 microg g(-1)d.wt. soil, during the crop period of 2003. The insecticide residues for 2004 ranged between 0.59+/-0.38 and 13.42+/-0.71 microg g(-1)d.wt. soil and for 2005 it ranged between 0.48+/-0.22 and 19.81+/-0.33 microg g(-1)d.wt. soil. An average half life of acetamiprid in our treated field was 11.2+/-1.7 days for all three years. Similarly, the soil from natural area and control were also tested for insecticide residues. No detectable insecticide residues had been found. Soil from three localities i.e. natural, control and experimental fields were tested for different enzyme activities. Nitrate reductase, arginine deaminase, urease and dehydrogenase activities were high in natural soil in comparison to control soil and insecticide treated soil in all three experimental years. At the same time, nitrate reductase activity was all time low in acetamiprid treated soil. Acetamiprid had inhibitory effects on nitrate reductase, arginine deaminase and urease activities. After first treatment (43 days after crop sowing), nitrate reductase (41%), arginine deaminase (22%) and urease (35%) activities were declined. Dehydrogenase activity increased to 22% after first insecticide application. Enzyme activities were recovered at the end of each crop season. Therefore, it can be attributed that agricultural practices, weather conditions and use of acetamiprid might be responsible for the different level of enzyme activities in soil.     

Soil persistence of triasulfuron herbicide as affected by biotic and abiotic factors

Persistence of triasulfuron [3-(6-methoxy-4methyl-1,3,5-triazin-2-yl)-1-{2-(2-chloroethoxy)-phenylsulfonyl}-urea] in soil was studied under wheat crop and laboratory conditions. Field experiment was conducted in the farms of Agronomy Division, Indian Agricultural Research Institute (IARI), New Delhi. Randomized block design (RBD) was followed with four replicates and two rates of treatments along with control and weedy check. Triasulfuron was applied as post-emergent application to wheat crop at two rates of application viz., 15 g and 20 g a.i. ha-1. Soil samples at 0 (3 h), 1, 3, 5, 7, 10, 15, 20, and 30-day intervals after application were drawn, extracted, cleaned up, and analyzed for herbicide residues by high performance liquid chromatography (HPLC) using C18 column and methanol: water (8:2) as mobile phase at 242 nm wave length. Effect of microbial activity and soil pH was studied under laboratory conditions. Dissipation of triasulfuron followed a first-order-rate kinetics. Residues dissipated from field soil with half-life of 5.8 and 5.9 days at two rates of application. The study indicated biphasic degradation with faster rate initially (t1/2 = 3.7 days), followed by a slower dissipation rate at the end (t1/2 = 9.4 days). Similar trend was observed with non-sterile soil in laboratory with a longer half-life. Acidic pH and microbial activity contributed toward the degradation of triasulfuron in soil.     

Non-aromatic hydrocarbons in surface sediments near the Pearl River estuary in the South China Sea

Surface sediment samples at 4 sites along an offshore transect from outer continental shelf off the Pearl River estuary to the shelf slope region of the northern South China Sea, have been analyzed for total organic carbon (TOC), total nitrogen (TN), solvent extractable organic matter (EOM) and non-aromatic hydrocarbons. TOC, TN and EOM show distinct spatial variations. Their highest values are all recorded at the shelf slope region. EOM varies from 18.70-38.58 microgg(-1) dry sediment and accounts for 0.20-0.72% of the TOC contents. The non-aromatic hydrocarbons are an important fraction of EOM. Their contents range from 3.43-7.06 microgg(-1) dry sediment. n-Alkanes with carbon number ranging from 15-38 are identified. They derive from both biogenic and petrogenic sources in different proportions. Results of isoprenoid hydrocarbons, hopanes and steranes also suggest possible petroleum contamination.     

Bacterial, azotobacter, actinomycetes, and fungal population in soil after diazinon, imidacloprid, and lindane treatments in groundnut (Arachis hypogaea L.) fields

Bacterial, azotobacter, actinomycetes, and fungal populations were determined in groundnut (Arachis hypogaea L.) fields between July and November for three consecutive years (1997-1999) after insecticide treatments. Diazinon was applied for both seed and soil treatments. However, imidacloprid and lindane were used for seed treatments. An average half-life (t1/2) of diazinon in seed- and soil-treated fields was found to be 29.32 and 34.87 days, respectively. Its residues were found for 60 days in both cases. In diazinon seed treatment, an increase in azotobacter, fungi, and actinomycetes populations was observed in samples from the 15th and 30th days, and this trend continued until crop harvest. However, the bacterial population had not been affected by this treatment. The diazinon soil treatment had indicated some significant adverse effects on fungi and actinomycetes population, which recovered after 30 days. The population of bacteria and azotobacter increased significantly in this treatment. The residues of imidacloprid and lindane were found for 90 and 120 days with an average half-life of 40.9 and 53.3 days, respectively. Imidacloprid had no significant effect on fungi and actinomycetes populations up to 15 days, and between 15 to 60 days some adverse effects were indicated. However, some significant increases in bacterial and azotobacter population were observed. Lindane had no effect on bacterial and fungal population. However, its adverse effects were observed in actinomycetes and azotobacter populations between 30 to 60 days.     

Influence of solid dairy manure and compost with and without alum on survival of indicator bacteria in soil and on potato

We measured Escherichia coli, Enterococcus spp. and fecal coliform numbers in soil and on fresh potato skins after addition of solid dairy manure and dairy compost with and without alum (Al(2)(SO(4))(3)) treatment 1, 7, 14, 28, 179 and 297 days after application. The addition of dairy compost or solid dairy manure at rates to meet crop phosphorus uptake did not consistently increase E. coli and Enterococcus spp. and fecal coliform bacteria in the soil. We did not detect E. coli in any soil sample after the first sampling day. Seven, 14, 28, 179 and 297 days after solid dairy waste and compost and alum were applied to soil, alum did not consistently affect Enterococcus spp. and fecal coliform bacteria in the soil. We did not detect E. coli in any soil, fresh potato skin or potato wash-water at 214 days after dairy manure or compost application regardless of alum treatment. Dairy compost or solid dairy manure application to soil at rates to meet crop phosphorus uptake did not consistently increase Enterococcus spp. and fecal coliform numbers in bulk soil. Solid dairy manure application to soil at rates to meet crop phosphorus uptake, increased Enterococcus spp. and fecal coliform numbers in potato rhizosphere soil. However, fresh potato skins had higher Enterococcus spp. and fecal coliform numbers when solid dairy manure was added to soil compared to compost, N and P inorganic fertilizer and N fertilizer treatments. We did not find any E. coli, Enterococcus or total coliform bacteria on the exterior of the tuber, within the peel or within a whole baked potato after microwave cooking for 5 min.     

Monitoring of pesticide residues in a cotton crop soil

This paper reports on the residues of methyl parathion (O,O-dimethyl O-4-nitrophenyl phosphorothioate), trifluralin (alpha, alpha, alpha-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), endosulfan [(1, 4, 5, 6, 7, 7-hexachloro-8, 9, 10-trinorborn-5-en-2, 3-ylenebismethylene) sulfite] and dimethoate (O, O-dimethyl S-methylcarbamoylmethyl phosphorodithioate) in a cotton crop soil. Soil samples (0-15 cm) were collected at different periods from the cotton crop farm and subjected to Soxhlet extraction. The extracted material was analysed after clean-up by a HP5890 II gas chromatograph equipped with a 63Ni electron-capture detector (ECD-63Ni) and fitted with a 25 m x 0.2 mm i.d. fused silica capillary column [Ultra-2 (5% phenylmethyl polysiloxane)]. The recoveries of the pesticide residues from the spiked control soil were determined after Soxhlet extraction and C18 cartridges clean-up by using radiotracer techniques with the corresponding 14C-pesticides. The results show that in the cotton crop soil the pesticide residues under study were present in the range of 0.1 to 0.4 mg.kg-1. Endosulfan was found to be rapidly degraded in the soil and formed a sulfate metabolite.