Response to the insecticide chlorpyrifos by arthropods on maize canopy     

M. Michereff Filho  T. M. C. Della Lucia  I. Cruz  R. N. C. Guedes 《国际虫害防治杂志》2013,59(3):203-210

We assessed the response of maize canopy arthropods to the insecticide chlorpyrifos. Four 0.3 ha (18 2 180 m) plots were divided into two subplots, a control and a treated area. During tasseling of the plants, the treated area was sprayed twice, with an interval of 3 days. Ten plants were sampled: 1 day before spraying, and 7, 14, 21 and 28 days after spraying. The insecticide had no effect on insect herbivores: a high density of Spodoptera frugiperda larvae was present in the treated plots. A few predator arthropod species were negatively affected by the insecticide, but their numbers or activity increased 2 weeks after the treatment of the plots. A canonical variate analysis showed no pronounced effect of the insecticide on arthropod communities; the largest variations on species abundance were related to sampling occasion. These results can be explained by the combination of the short period of chlorpyrifos residual activity on the plant surface and the great potential for recolonization of the areas by most of the monitored arthropods.  相似文献   

Morphological, pathological and genetic diversity of Colletotrichum species responsible for anthracnose in papaya (Carica papaya L)     

Claudia Torres-Calzada  Raul Tapia-Tussell  Inocencio Higuera-Ciapara  Daisy Perez-Brito 《European journal of plant pathology / European Foundation for Plant Pathology》2013,135(1):67-79

Recently, anthracnose has become a major problem in papaya production and postharvest stages. The occurrence of both Colletotrichum gloeosporioides and Colletotrichum capsici has been demonstrated in this crop. The differential response of these pathogens to fungicides has highlighted the need to use rapid and accurate techniques to identify them. Thus, the objective of this study was to reveal the genetic diversity of Colletotrichum isolates in Mexican papaya fields. C. gloeosporioides-and C. capsici-specific primers were successfully used to detect the pathogens from different papaya parts. A combination of morphological characters, molecular techniques and pathogenicity tests were used to characterize 37 isolates from different localities of five papaya-producing states. Analyses of the 5.8-ITS region and arbitrarily primed-PCR revealed intraspecific groups; most of the isolates within these groups have the same geographical location and morphological characteristics. Knowledge of the genetic diversity of Colletotrichum spp. in Mexican papaya fields will facilitate the identification of the pathogen population in this crop in order to select the appropriate fungicide to control anthracnose, as well as to improve genetic resistance breeding programs.  相似文献   

Correlation between carcass condemnations in slaughterhouses and official notifications of cattle testing positive for tuberculosis     

Junqueira Junior  Danilo Guedes  de Souza  Mariana Assunção  Nunes Júnior  Sebastião Corrêa  Lima  Anna Monteiro Correia 《Tropical animal health and production》2020,52(2):823-828

Tropical Animal Health and Production - The objective of this study was to analyze the correlation between condemnations in slaughterhouses situated in Minas Gerais State and notifications to the...  相似文献   

Pharmacokinetics and clinical effects of xylazine and dexmedetomidine in horses recovering from isoflurane anesthesia     

Alonso Guedes  Heather Knych  Laura Tucker  Daniel C. Almeida  Caroline F. Baldo  Erin Wendt-Hornickle  Sandra Allweiler 《Journal of veterinary pharmacology and therapeutics》2020,43(4):369-376

This study determined the pharmacokinetics and compared the clinical effects of xylazine and dexmedetomidine in horses recovering from isoflurane anesthesia. Six healthy horses aged 8.5 ± 3 years and weighing 462 ± 50 kg were anesthetized with isoflurane for 2 hr under standard conditions on two occasions one-week apart. In recovery, horses received 200 μg/kg xylazine or 0.875 μg/kg dexmedetomidine intravenously and were allowed to recover without assistance. These doses were selected because they have been used for postanesthetic sedation in clinical and research studies. Serial venous blood samples were collected for quantification of xylazine and dexmedetomidine, and the pharmacokinetic parameters were calculated. Two individuals blinded to treatment identity evaluated recovery quality with a visual analog scale. Times to stand were recorded. Results (mean ± SD) were compared using paired t tests or Wilcoxon signed-ranked test with p < .05 considered significant. Elimination half-lives (62.7 ± 21.8 and 30.1 ± 8 min for xylazine and dexmedetomidine, respectively) and steady-state volumes of distribution (215 ± 123 and 744 ± 403 ml/kg) were significantly different between xylazine and dexmedetomidine, whereas clearances (21.1 ± 17.3 and 48.6 ± 28.1 ml/minute/kg), times to stand (47 ± 24 and 53 ± 12 min) and recovery quality (51 ± 24 and 61 ± 22 mm VAS) were not significantly different. When used for postanesthetic sedation following isoflurane anesthesia in healthy horses, dexmedetomidine displays faster plasma kinetics but is not associated with faster recoveries compared to xylazine.  相似文献   

Chemical composition and biological activity of Salvia officinalis L. essential oil against Aphis fabae Scopoli (Hemiptera: Aphididae)     

Harizia  Abdelkader  Benguerai  Abdelkader  Elouissi  Abdelkader  Mahi  Tayeb  Bonal  Raul 《植物病害和植物保护杂志》2021,128(6):1547-1556

Journal of Plant Diseases and Protection - This study investigated chemical composition, repellent and biocidal activities of Salvia officinalis essential oil against Aphis fabae. In total, 19...  相似文献   

Dry heat popping of amaranth seed might damage some of its essential amino acids     

Luis Raul Tovar  E. Brito  T. Takahashi  T. Miyazawa  J. Soriano  K. Fujimoto 《Plant foods for human nutrition (Dordrecht, Netherlands)》1989,39(4):299-309

Amaranth was a major crop among the Aztecs. In Mexico the seed is popped and eaten with brown sugar. The crude protein content of the seed is 14±2% but its contents of lysine and tryptophan are 6.2 and 1.6 g/16 g N respectively. We developed a popping method based on a fluid bed system (FBS) whereas the traditional method (TM) is just to pop the seeds manually in a hot plate. Assays carried out were evaluation of racemization of the amaranth protein due to heat treatment, amino acid composition of the raw and heat treated seeds and a biological experiment testing whether leucine was the most limiting amino acid of amaranth protein. Male rats were fed both popped amaranths and roasted amaranth. Parboiled amaranth and casein were controls. The results were: (a) Lys, Arg and Cys were damaged in the heat treated seeds; (b) Asp, Met, Glu, Ala and Phe were racemized in that decreasing order in the seeds popped and roasted by the TM; (c) the estimated net protein retention (NPR) and estimated net protein utilization (NPU) of popped amaranths by either method were not different, but were lower than for the parboiled amaranth. The parboiled amaranth was not different from casein; (d) Leu was not the most limiting amino acid in any of the amaranth seeds tested. After Lys, sulfur amino acids appear to be the next most limiting in severely heat treated amaranth. The FBS seems to be a promising method for popping amaranth at industrial level.  相似文献   

Vermicomposting as an Added-Value Post-treatment for Livestock Waste Composts     

Enrique Agulló  Mauricio Martínez-Fernández  Maria Dolores Pérez-Murcia  Aurelia Pérez-Espinosa  Raul Moral 《Communications in Soil Science and Plant Analysis》2015,46(4):208-218

The aim of this work was to study the effects of vermicomposting on selected properties of composts derived from animal and plant wastes. For this, two different worm beds were established and fed with two composts: C1, made from goat (Capra aegagrus hircus) manure and rosemary (Rosmarinus officinalis) pruning wastes, and C2, made from rabbit (Oryctolagus cuniculus) manure and grass clippings, to study the quality of the final vermicomposts. Physical and chemical properties were determined in the end products. Vermicomposting improved several properties of the composts, increasing their total water-holding capacity (in C1, from 333 to 451 mL/L, and in C2, from 371to 419 mL/L), reducing salinity (in C1, from 6.8 to 2.4 dS/m, and in C2, from 10.3 to 4.6 dS/m), and balancing pH in the final composts obtained, especially in C1 (from 8.57 to 8.02). The type of raw material used in the worm beds significantly influenced the final characteristics of the end products obtained and the development of the process, with more favorable results being obtained with the compost derived from rabbit manure and grass clippings (C2).  相似文献   

Urease activity and its relation to soil organic matter, microbial biomass nitrogen and urea-nitrogen assimilation by maize in a Brazilian Oxisol under no-tillage and tillage systems   总被引：3，自引：0，他引：3  

R. Roscoe  C. A. Vasconcellos  A. E. Furtini-Neto  G. A. A. Guedes  L. A. Fernandes 《Biology and Fertility of Soils》2000,32(1):52-59

 We studied the relationship between urease activity (UA) and soil organic matter (SOM), microbial biomass N (N_biom) content, and urea-N fertilizer assimilation by maize in a Dark Red Latosol (Typic Haplustox) cultivated for 9 years under no-tillage (NT), tillage with a disc plough (DP), and tillage with a moldboard plough (MP). Two soil depths were sampled (0–7.5 cm and 7.5–15 cm) at 4 different times during the crop cycle. Urea was applied at four different rates, ranging from 0 to 240 kg N ha^–1. The levels of fertilizer N did not affect the UA, SOM content, and N_biom content. No significant difference between the treatments (NT, DP, and MP) was observed for SOM during the experiment, probably because the major part of the SOM was in recalcitrant pools, since the area was previously cultivated (conventional tillage) for 20 years. The N_biom content explained 97% and 69% of the variation in UA in the upper and deeper soil layer, respectively. UA and biomass N were significantly higher in the NT system compared to the DP and MP systems. The highest maize productivity and urea-N recovery was also observed for the NT system. We observed that the increase in urea-N losses under NT, possibly as a consequence of a higher UA, was compensated for by the increase in N immobilized in the biomass. Received: 2 July 1999  相似文献   

BOOK REVIEW     

NC Whelan 《Australian veterinary journal》2003,81(7):410-410

  相似文献   

Inclusion of licuri meal in the diet of pasture dairy cows     

Costa  Evely Giovanna Leite  da Silva  Fabiano Ferreira  Silva  Robério Rodrigues  Porto  Antonio Ferraz  Santiago  Bismarck Moreira  Rocha  Leone Campos  Cruz  Aline Gonçalves  Guedes  Anna Caroline Ferreira  Neto  Teotônio Martins  Vieira  Edvaldo Alves 《Tropical animal health and production》2019,51(8):2505-2511

Tropical Animal Health and Production - The objective of this study was to evaluate the inclusion of increasing levels of licuri meal as a substitute for soybean bran in the diet of pasture-based...  相似文献