Effect of seeders and tillage equipment on vertical distribution of oilseed rape stubble     

Olivier Schneider  Jean Roger-Estrade  Jean-Noël Aubertot  Thierry Dor 《Soil & Tillage Research》2006,85(1-2):115-122

When the spreading of a disease depends on the proportion of infected residues remaining at soil surface it is of crucial importance to analyse the effects of tillage practices on the vertical distribution of stubble. This is the case with phoma stem canker (blackleg), whose epidemics are initiated in autumn, by air-borne ascospores released from stubble located at the soil surface. We compared initial vertical distribution of oilseed rape residues to those observed after sowing and various tillage operations (rotary harrowing, stubble disking, chiselling and mouldboard ploughing). Almost 20% of the initially buried residue was brought back to soil surface with seeding. Rotary harrow brought 40% of the residue buried in the 0–10 cm layer up to the surface and left unburied about 70% of surface residue. Stubble disking appeared to be more efficient for residue burial than chiselling. Mouldboard plough was the only tool that buried all residues. A simple model was developed that predicted burial and return to the soil surface of potentially infected residues as a function of tillage practices used after harvest. Simulation of different tillage sequences showed that the order in which tools were used also affected location of residues. Our results highlighted the importance of tillage in the cultural control of phoma stem canker and will contribute to the definition of integrated pest management strategies for oilseed rape.  相似文献   

Photodegradation of imidacloprid   总被引：4，自引：0，他引：4  

Wamhoff H  Schneider V 《Journal of agricultural and food chemistry》1999,47(4):1730-1734

The photolytic decomposition of the insecticide imidacloprid (1) in HPLC grade water and of imidacloprid as the formulated product Confidor insecticide in tap water was studied using HPLC methodology. The structures of several degradates have been determined in aquatic medium, and the DT(50) values of imidacloprid and Confidor have been measured. In addition, the influence of TiO(2) on the photodegradation of Confidor was studied. The photoproduct 1-(6-chloro-3-pyridinyl)methyl-2-imidazolidinone (5) has been identified as the main degradate in each of the three series of experiments by several analytical techniques. The photolytic half-lives for imidacloprid under the conditions of this study were 43 min in HPLC grade water, 126 min formulated as Confidor in tap water, and 144 min formulated as Confidor in tap water in the presence of TiO(2).  相似文献   

Rapid fluorescence screening assay for enrofloxacin and tetracyclines in chicken muscle     

Schneider MJ 《Journal of agricultural and food chemistry》2004,52(26):7809-7813

A simple, rapid fluorescence assay was developed for screening both enrofloxacin (ENRO) and tetracyclines in chicken muscle at the U.S. tolerance levels (300 ng/g and 2 microg/g, respectively). Screening for both classes of antibiotics is accomplished using one extraction, thus simplifying and expediting the process. The method requires an initial extraction of chicken muscle with 1% acetic acid in acetonitrile, centrifugation, and analysis of the supernatant for ENRO fluorescence. After addition of ammonium hydroxide, magnesium chloride, and methanol, followed by centrifugation and filtration, the supernatant can be measured for tetracycline fluorescence. Chlortetracycline (CTC) was chosen as a representative tetracycline to demonstrate the method, as it displays intermediate sensitivity among the three tetracyclines approved in the U.S. Comparison of the fluorescence of control and tolerance-level-fortified samples of both ENRO and CTC shows no overlap. Setting a threshold as the average fortified fluorescence minus 3sigma allows for successful screening, as illustrated with blind samples as controls or fortified with ENRO and/or CTC over a range of concentrations. This method can provide an alternative or supplemental approach to currently used microbial screening assays.  相似文献   

Measurement of nitrite and nitrate in blood   总被引：1，自引：0，他引：1  

N R Schneider  R A Yeary 《American journal of veterinary research》1973,34(1):133-135

  相似文献   

A serologic survey of veterinarians for antibody to feline leukemia virus   总被引：1，自引：0，他引：1  

R Schneider  J L Riggs 《Journal of the American Veterinary Medical Association》1973,162(3):217-219

  相似文献   

Morphological evidence of the interaction between plasma cells and macrophages in beagle dogs.     

P Schneider 《Veterinary pathology》1979,16(3):385-387

  相似文献   

Oral Immunisation of Foxes against Rabies: A Field Study     

F. Steck  A. Wandeler  P. Bichsel  S. Capt  L. Schneider 《Zoonoses and public health》1982,29(5):372-396

  相似文献   

Comparative prevalence of four enterotoxin genes among Escherichia coli isolated from swine   总被引：15，自引：0，他引：15  

H W Moon  R A Schneider  S L Moseley 《American journal of veterinary research》1986,47(2):210-212

Presence of Escherichia coli enterotoxin genes LT (heat-labile enterotoxin), STaP (heat-stable enterotoxin a, porcine genotype), STaH (heat-stable enterotoxin a, human genotype), and STb (heat-stable enterotoxin b) among 874 swine isolates of E coli was determined, using DNA probes and the DNA colony hybridization technique. Of the 874 isolates evaluated, 45% hybridized with at least one of the enterotoxin gene probes and were designated as enterotoxigenic E coli (ETEC). Eighty-five percent of the ETEC were from pigs with enteric colibacillosis. The remaining 15% were from pigs with edema disease or various other diseases, and from healthy swine. Seventy-four percent of the ETEC hybridized with the STb probe, 52% with STaP, and 31% with LT; ETEC did not hybridize with the STaH probe. Most of the ETEC hybridized with more than one enterotoxin gene probe. Isolates that hybridized with the LT probe also hybridized with STb. The most prevalent gene combination was LT-STb. However, 35% of the ETEC from neonatal (less than or equal to 1 week old) swine with enteric colibacillosis were of the STaP-only genotype, and 33% of the ETEC from older swine with enteric colibacillosis were of the STb-only genotype.  相似文献   

The significance of yellow-body enucleation in the development of ovarian adhesions in cattle]     

F Schneider  M Berchtold  A Murbach  R Büchi 《Berliner und Münchener tier?rztliche Wochenschrift》1979,92(6):105-107

  相似文献   

Preliminary results in the use of a method for determining estrone sulfate in experimental studies on pregnant sows     

B Lampe  G Bl?dow  F Schneider 《Archiv fuer experimentelle veterinaermedizin》1987,41(3):359-365

  相似文献