Testing MACRO (version 5.1) for pesticide leaching in a Dutch clay soil   总被引：2，自引：0，他引：2  

Scorza Júnior RP  Jarvis NJ  Boesten JJ  van der Zee SE  Roulier S 《Pest management science》2007,63(10):1011-1025

Testing of pesticide leaching models against comprehensive field-scale measurements is necessary to increase confidence in their predictive ability when used as regulatory tools. Version 5.1 of the MACRO model was tested against measurements of water flow and the behaviour of bromide, bentazone [3-isopropyl-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide] and imidacloprid [1-(6-chloro-3-pyridylmethyl)-N-nitroimidazolidin-2-ylideneamine] in a cracked clay soil. In keeping with EU (FOCUS) procedures, the model was first calibrated against the measured moisture profiles and bromide concentrations in soil and in drain water. Uncalibrated pesticide simulations based on laboratory measurements of sorption and degradation were then compared with field data on the leaching of bentazone and imidacloprid. Calibrated parameter values indicated that a high degree of physical non-equilibrium (i.e. strong macropore flow) was necessary to describe solute transport in this soil. Comparison of measured and simulated bentazone concentration profiles revealed that the bulk of the bentazone movement in this soil was underestimated by MACRO. Nevertheless, the model simulated the dynamics of the bentazone breakthrough in drain water rather well and, in particular, accurately simulated the timing and the concentration level of the early bentazone breakthrough in drain water. The imidacloprid concentration profiles and its persistence in soil were simulated well. Moreover, the timing of the early imidacloprid breakthrough in the drain water was simulated well, although the simulated concentrations were about 2-3 times larger than measured. Deep groundwater concentrations for all substances were underestimated by MACRO, although it simulated concentrations in the shallow groundwater reasonably well. It is concluded that, in the context of ecotoxicological risk assessments for surface water, MACRO can give reasonably good simulations of pesticide concentrations in water draining from cracking clay soils, but that prior calibration against hydrologic and tracer data is desirable to reduce uncertainty and improve accuracy.  相似文献   

Anthocyanins present in selected tropical fruits: acerola, jambolão, jussara, and guajiru     

de Brito ES  de Araújo MC  Alves RE  Carkeet C  Clevidence BA  Novotny JA 《Journal of agricultural and food chemistry》2007,55(23):9389-9394

Many tropical fruits are rich in anthocyanins, though limited information is available about the characterization and quantification of these anthocyanins. The identification and quantification of anthocyanin pigments in four tropical fruits were determined by HPLC-MS/MS. Fruits studied included acerola (Malphigia emarginata), jussara (Euterpe edulis), jambol?o (Syzygium cumini), and guajiru (Chrysobalanus icaco). All four fruits were found to contain anthocyanin pigments. Anthocyanidin backbones included cyanidin, delphinidin, peonidin, pelargonidin, petunidin, and malvidin. Guajiru contained several acylated forms, while acerola, jussara, and jambol?o contained only nonacylated glycosides. These results demonstrate that these tropical fruits are rich in anthocyanins and that the anthocyanins are widely ranging in anthocyanidin backbone, glycosylation, and acylation.  相似文献   

Structure of genetic variation in vegetative phenology of Cedrela odorata L.: implications for tree breeding     

Hernández-Máximo  Edgar  Vargas-Hernández  J. Jesús  López-Upton  Javier  Sánchez-Monsalvo  Vicente 《New Forests》2022,53(3):387-409

New Forests - The study of vegetative phenology is important to understand adaptation to different environments and potential trade-offs with growth traits. Crown leaf-out and leaf-fall phenology...  相似文献   

Who ate my chocolate? Small mammals and fruit damage in cacao agroforestry     

Cassano  Camila Righetto  Rios  Vanessa Araújo  Gaiotto  Fernanda Amato 《Agroforestry Systems》2021,95(8):1415-1425

Agroforestry Systems - Small mammals interfere in plant dynamics through seed and seedling predation, and seed dispersion. In anthropogenic systems, some species provide ecosystem services while...  相似文献   

Litter production and nutrient deposition from native woody species in the Brazilian semi-arid region     

Primo  Anacláudia Alves  Araújo  Maria Diana Melo  Silva  Karla da Fonseca  Silva  Ludmyla Araújo  Pereira  Graziella de Andrade Carvalho  Fernandes  Francisco Éden Paiva  Pompeu  Roberto Cláudio Fernandes Franco  Natale  William  de Souza  Henrique Antunes 《Agroforestry Systems》2021,95(8):1459-1464

Agroforestry Systems - The use of native trees in agroecosystems is a promising way to increase litter deposition and nutrient cycling and foster the recovery of degraded areas, especially in...  相似文献   

Stocking density evaluation on Catarina scallop (Argopecten ventricosus,Sowerby II, 1842) larvae to improve hatchery production     

Mazón-Suástegui  José Manuel  Arcos-Ortega  Guadalupe Fabiola  Lodeiros  César  Tovar-Ramírez  Dariel  López-Carvallo  Jesús Antonio 《Aquaculture International》2022,30(4):1741-1754

The Catarina scallop Argopecten ventricosus is a highly valued resource. Although its hatchery spat production has already been reported, the effects of initial larval stocking density have never been reported for production purposes. This study evaluates A. ventricosus growth and survival in triplicate using three stocking densities: low (LD; 2 larvae mL^?1), medium (MD; 4 larvae mL^?1), and high (HD; 6 larvae mL^?1). Three-day old larvae were reared in 18-L plastic carboy at 25.6?±?0.5 °C and fed with a microalgal blend of Isochrysis galbana and Chaetoceros calcitrans (1:1 cell number ratio) for 7 days, equivalent to 10 post-fertilization days (PFD). Higher specific growth rate was recorded at LD (15.8?±?0.2%) after 8 PFD of culture compared to MD (1.6?±?0.5%) and HD (4.1?±?1.8%) densities. The least time required for 60% of the larvae to reach the pediveliger stage was recorded at LD condition (10 PFD). Higher survival was recorded at HD (58.8?±?3.1%) at 8 PFD compared to MD (53.5?±?3.1%) and LD (43.9?±?3.0%). After 8 PFD, stocking density was highly related to larval growth and survival. To increase production and growth, and reduce the time required to reach pediveliger stage, stocking density should start with 6 larvae mL^?1 and be reduced to 2 larvae mL^?1 at 7 PFD.

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The Bolivian “Altiplano” and “Valle” sheep are two different peripatric breeds     

Pere M. Parés-Casanova  Raúl Pérezgrovas Garza 《Tropical animal health and production》2014,46(5):777-781

Forty-nine sheep belonged to the Andean Altiplano region (“Altiplano”) and 30 in the lowland regions of Bolivia (“Valle”), aged 1 to 4 years, were wool sampled to determine the extent of difference between these local breeds. Fibre length and the percentage of each type of fibre (long-thick, short-thin and kemp), yield and fibre diameter were measured. There was a highly significant difference between the two sheep populations that were not clearly separated in the first two principal component of a principal components analysis (PC); the first PC explained 67.1 % and the second PC explained 26.6 % of the total variation. The variables that contributed most to the separation of the sheep populations were the percentage of long-thick and short-thin fibres in the first PC and yield in the second PC. A discriminant analysis, which was used to classify individuals with respect to their breeding, achieved an accurate classification rate of 84.2 %. Thus, the Altiplano and Valle sheep must be viewed as two closely peripatric breeds rather than different “ecotypes”, as more than 80 % could be correctly assigned to one of the breeds; however, the differences are based on composition of long-thick and short-thin fibres and yield after alcohol scouring.  相似文献   

Short-wave solar radiation level willingly tolerated by lactating Holstein cows in an equatorial semi-arid environment     

Steffan Edward Octávio Oliveira  Cíntia Carol de Melo Costa  João Batista Freire de Souza Jr  João Paulo Araújo Fernandes de Queiroz  Alex Sandro Campos Maia  Leonardo Lelis de Macedo Costa 《Tropical animal health and production》2014,46(8):1413-1417

The amount of short-wave solar radiation willingly tolerated by lactating Holstein cows on pasture was determined in an equatorial semi-arid environment. The study was carried out on a dairy farm located in Limoeiro do Norte, CE, northeastern Brazil. The observed behaviours were as follows: grazing, under the sun, under the shade, standing, lying, ruminating, idling and wallowing in the water. The behaviours were recorded using instantaneous scan sampling at regular intervals of 15 min from 0600 to 1800 hours over 5 days. On all sampling days, the meteorological variables, including local short-wave solar radiation (R _S-W, W m^?2), were recorded. The R _S-W data were divided into five levels. The sun exposure was more frequent under low (100 %) and moderately low (97 %) levels, when R _S-W remained below 500 W m^?2. The grazing was more intense under low (100 %) and moderately low (93 %) levels. Above 500 W m^?2, the grazing time significantly decreased (11 %). The cows avoided grazing under high (0 %) and very high (0 %) levels, when R _S-W exceeded 700 W m^?2. The ruminating behaviour was more frequent under high (33 %) and very high (37 %) levels, in which the highest averages of R _S-W were recorded (815 and 958 W m^?2, respectively). The standing posture was more frequent under low (100 %) and moderately low (97 %) levels. Therefore, the critical R _S-W level that motivates cows to stop grazing and seek shade was in the interval between 500 and 700 W m^?2.  相似文献   

Evaluation of hepatitis E virus infection between different production systems of pigs in Brazil     

Marconni Victor da Costa Lana  Noemi Rovaris Gardinali  Raquel Aparecida Sales da Cruz  Letícya Lerner Lopes  Gustavo Sousa Silva  João Garcia Caramori Júnior  Anderson Castro Soares de Oliveira  Marcos de Almeida Souza  Edson Moleta Colodel  Amauri Alcindo Alfieri  Caroline Argenta Pescador 《Tropical animal health and production》2014,46(2):399-404

The objectives of this study were to (1) investigate the occurrence of hepatitis E virus (HEV) in pigs from large-scale and family-scale farms, (2) genetically characterize the strains isolated, and (3) study the pathogenesis of swine HEV infection via immunohistochemistry. A total of 50 pigs from 10 farms in Mato Grosso State, Brazil were divided according to type of production system into either large-scale farms (n?=?5) or family-scale farms (n?=?5). Samples of liver, gallbladder, small and large intestines, bile, and feces from the pigs were analyzed by nested PCR with primers targeting the ORF2 region of HEV and by immunohistochemistry. Of the eight HEV-positive samples from pigs of family-scale farms, phylogenetic analysis revealed that seven of the swine HEV isolates clustered with subtype 3b of genotype 3 and one isolate was categorized with subtype 3 f. The HEV antigen was detected mainly in the small intestine samples from family-scale farms, suggesting an early stage HEV infection. HEV was not detected in the samples of pigs from large-scale farms, reinforcing the need for additional studies to evaluate the risk of transmission of HEV to humans from pigs from family-scale farms in Mato Grosso State.  相似文献   

Evaluation of the effectiveness of Duddingtonia flagrans and Monacrosporium thaumasium in the biological control of gastrointestinal nematodes in female bovines bred in the semiarid region     

Manoel Eduardo da Silva  Fabio Ribeiro Braga  Luana Alcântara Borges  Jair Mendes de Oliveira  Walter dos Santos Lima  Marcos Pezzi Guimarães  Jackson Victor de Araújo 《Veterinary research communications》2014,38(2):101-106

Brazil has a herd of 212 million cattle and 171 million hectares of pastures that produce approximately 96 % of Brazilian beef. The Brazilian production system enables animal infection by endoparasites, which are considered one of the main obstacles for the development of this industry and are responsible for considerable economic losses. The control of parasitic diseases is performed via the administration of antiparasitic drugs, but they leave residues of the products in the treated animal, affect non-target organisms and select resistant strains of the parasites. The species D. flagrans and M. thaumasium are promising and sustainable alternatives for controlling gastrointestinal helminths of ruminants and other herbivores. In this study, we evaluated the efficacy of isolates of these species, formulated in a sodium alginate matrix and administered twice a week, to reduce the number of environmental infective larvae of gastrointestinal nematodes that affect prepubescent zebu females. The treated animals presented fewer eggs and a lower number of infective larvae per gram of faeces (p?<?0.05). The pastures occupied by treated animals showed a statistically significant reduction (p?<?0.05) of the number of L₃ and, furthermore, the genera Cooperia sp., Haemonchus sp., and Oesophagostomum sp. were the most prevalent. The average weight of the animals did not differ statistically (p?>?0.05) among the treated and control groups. The use of sodium alginate pellets as vehicle for delivery of the fungus mycelia D. flagrans (isolate AC001) and M. thaumasium (isolate NF34A) proved effective in controlling trichostrongylids in prepubescent cows bred in the semi-arid region, with an effective reduction in the number of infective larvae in the pastures.  相似文献