Search results for "PEST"
showing 10 items of 1124 documents
Pesticide residues in Lake Albufera, Valencia, Spain.
1987
Abstract Analysis of water samples from the lake in Albufera, Valencia, indicates that the pesticides molinate, benthiocarb, and fenitrothion do not reach levels that are lethal to fish.
Fate of the herbicides glyphosate, glufosinate-ammonium, phenmedipham, ethofumesate and metamitron in two Finnish arable soils.
2006
The fate of five herbicides (glyphosate, glufosinate-ammonium, phenmedipham, ethofumesate and metamitron) was studied in two Finnish sugar beet fields for 26 months. Soil types were sandy loam and clay. Two different herbicide-tolerant sugar beet cultivars and three different herbicide application schedules were used. Meteorological data were collected throughout the study and soil properties were thoroughly analysed. An extensive data set of herbicide residue concentrations in soil was collected. Five different soil depths were sampled. The study was carried out using common Finnish agricultural practices and represents typical sugar beet cultivation conditions in Finland. The overall obse…
Biochemistry and genetics of insect resistance to Bacillus thuringiensis.
2001
▪ Abstract Bacillus thuringiensis (Bt) is a valuable source of insecticidal proteins for use in conventional sprayable formulations and in transgenic crops, and it is the most promising alternative to synthetic insecticides. However, evolution of resistance in insect populations is a serious threat to this technology. So far, only one insect species has evolved significant levels of resistance in the field, but laboratory selection experiments have shown the high potential of other species to evolve resistance against Bt. We have reviewed the current knowledge on the biochemical mechanisms and genetics of resistance to Bt products and insecticidal crystal proteins. The understanding of th…
Survival of two strains of Phthorimaea operculella (Lepidoptera: Gelechiidae) reared on transgenic potatoes expressing a Bacillus thuringiensis cryst…
1998
[Otros] Survie de deux souches de Phthorimaea operculella (Lepidoptera : Gelechiidae) élevées sur des pommes de terre transgéniques exprimant la protéine CrylAb de Bacillus thuringiensis. Deux populations de Phthorimaea operculella (Zeller), l'une supposée résistante au DipelTM (une préparation commerciale de delta-endotoxines de Bacillus thuringiensis) et l'autre sensible, ont été cultivées sur quatre cultivars de pomme de terre, deux transgéniques de première génération, exprimant la protéine CrylAb de Bacillus thuringiensis, et deux non transformés. La population de papillons considérée comme résistante a présenté une mortalité inférieure à celle de l'autre population, mais n'était pas v…
Consumers perception of food safety related risk in the italian market
2019
The aim of this paper is to define the factors affecting the consumers' perception on food risk associated to the consumption of products (i) containing food additives, (ii) obtained with the use of pesticides, and (iii) processed through novel food technologies, in relation to different socio-economic and demographic characteristics, the source of acquisition of information on food safety issues, and the place of purchase of food. The study is based on a sample of 392 consumers, living in Italy, and it uses three ordered probit estimation models to process data collected. Findings show that food risk perception is greater among youngsters, mainly for the additives and residual pesticides i…
Investigationes on population dynamics and mortality of Phyllocnistis citrella in western Sicily (Italy)
2006
Population dynamics and mortality of P. citrella, and its natural enemies with parasitism levels in two different citrus orchards, sprayed and unsprayed, were investigated. The effect of host density on percentage parasitism and mortality was calculated by regression analyses. In both sites, over the 3-years period from 2002 to 2004, P. citrella was detected during the summer months and it was not found during the first flush. Population levels were low, never exceeding 3.0/leaf. P. citrella began to increase from June in 2002-2003 and from July in 2004. The monthly percentage parasitism of P. citrella in sprayed orchard fluctuated from 0 to 19%, while in unsprayed from 0 to 30%. High morta…
Multiscale analysis of the effects of the landscape context and of the agricultural practices on the pest pressure and on the use of insecticides in …
2023
In the context of the need to reduce the dependence of agricultural systems on the use of plant protection products, the identification of factors affecting the capacity of farmers to reduce the use of pesticides is a central issue. It has now been shown that, in certain production contexts, this reduction is possible without economic loss for the farms, by modifying the cropping systems. It can be hypothesised that this capacity to reduce pesticides will depend on local pest pressure, which is itself potentially affected by the regional and local landscape context of cropping systems. In this thesis, we quantified the effects of landscape context on pest pressure and pesticide use levels i…
Pestīšanas Armijas darbības tendences Latvijā pēdējā desmitgadē
2017
Pestīšanas armija pirmsākumos drosmīgi evaņģelizēja zemākajos sabiedrības slāņos un mazināja sociālās atstumtības risku. Tās sauklis bija: „Zupa, ziepes un pestīšana” (tāds tas ir joprojām). Tomēr laika gaitā Pestīšanas armija vairāk sāka nodarboties ar sociālās palīdzības sniegšanu, un evaņģelizācija kļuva otršķirīga. Arī Pestīšanas armija Latvijā 20./21.gs. mijā lielākoties nodarbojās ar sociālās palīdzības sniegšanu, taču tās piederīgo vidū bija arī tādi, kuri vēlējās atgriezties pie pirmsākumu darbības metodēm. Maģistra darba mērķis ir noskaidrot Pestīšanas armijas Latvijā darbības metodes pēdējā desmitgadē un virzienu, kuram pieder Pestīšanas armijas piederīgie – tradicionāli orientēto…
Analytical utility of quadrupole time-of-flight mass spectrometry for the determination of pesticide residues in comparison with an optimized column …
2009
Abstract A multiresidue method for the analysis of 30 pesticides with different physicochemical properties in fruits and vegetables was developed. The method involves a rapid and small-scale extraction procedure based on matrix solid-phase dispersion using octadecylsilyl (C18) as the dispersant and dichloromethane as the eluent. The target pesticides were determined using column high-performance liquid chromatography/triple quadrupole-tandem mass spectrometry (LC/QqQ-MS/MS). The method was validated for sensitivity, linearity, reproducibility, and accuracy. A recovery study was conducted at 3 different levels, and the average ranged from 74 to 99 for all of the studied compounds, with relat…
Filtration and ingestion rates of brachionus calyciflorus after exposure to endosulfan and diazinon
1992
Abstract 1. Rotifers Brachionus calyciflorus were exposed to endosulfan and diazinon to determine the effect on nitration and ingestion rates. 2. The experiments were carried out with the algae Nannochloris oculata in a density of 5 × 105 cell/ml. 3. Rates of filtration and ingestion were decreased significantly at sublethal concentrations of pesticide tested after 5 hr exposure. 4. The effective concentration at which filtration and ingestion rates were reduced to 50% of those in controls ( ec 50) were calculated for both toxicants.