Suppressing weeds in direct-seeded lowland rainfed rice: Effect of cutting dates and timing of fertilizer application     

Suchada Sanusan  Anan Polthanee  Alain Audebert  Surasak Seripong  Jean-Claude Mouret 《Crop Protection》2010

Weeds cause substantive yield losses in rainfed rice, particularly direct-seeded rice (DSR). Two field experiments were conducted in 2005 in north-east Thailand to examine the effects of cutting date and timing of fertilizer application on suppressed weed, growth and yield of DSR. Treatments consisted of two fertilizer applications to the main plots (top-dressing at the date of cutting and 15 days after cutting; DAC) and four cutting dates of the sub-plots. Rice and weed cutting was performed at 30, 45, 60 and 75 days after seeding (DAS), compared with an untreated control. Cutting resulted in a higher growth rate and improved grain yield of rice compared to the untreated control. Weed cutting at 60 DAS resulted in the greatest leaf area index, which contributed to the maximum number of tiller as well as maximum plant dry mass when observed at 30 DAC. Lower densities and dry weights of weeds at 30 DAC were observed when cutting was done 60 DAS, resulting in a higher grain yield than the other cutting dates. Timing of fertilizer application had no significant effect on the density and dry weight of grasses and broad-leaved weeds, but did have a significant affected on, resulting in the lowest density of sedges at 45 DAC was observed with fertilizer applied at cutting date. Rice grain yield was higher with top-dressing of fertilizer at 15 DAC than with fertilizer applied at cutting date. The cutting treatments resulted in higher net incomes than the untreated control. These results indicate that rice and weed cutting at an appropriate growth stage is an alternative method to chemical weed control for DSR in rainfed riceland.  相似文献   

Morphogenetic analysis of the phenotypic variability of the architectural unit of Hydrangea macrophylla     

Gilles Galopin  Jean-Claude Mauget  Philippe Morel 《Annals of Forest Science》2010,67(3):309-309

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Investigating the possible impact of atmospheric CO2 increase on Araucaria araucana wood density     

Paulina E. Pinto  Jean-Daniel Bontemps  Jean-Claude Pierrat  Tony Franceschini  Pierre Gelhaye  Jean-Claude Gégout  J. M. Leban 《European Journal of Forest Research》2016,135(2):389-401

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Evaluation of beta3-adrenoceptor-mediated relaxation in intact and endotoxin-treated equine digital veins   总被引：1，自引：0，他引：1  

Mallem MY  Gogny M  Gautier F  Bucas V  Desfontis JC 《American journal of veterinary research》2003,64(6):708-714

OBJECTIVE: To investigate the functional expression of beta3-adrenoceptors (beta3-ARs) in equine digital veins (EDVs) and to examine whether beta3-AR relaxation was altered in EDVs incubated with endotoxin. SAMPLE POPULATION: Forelimbs obtained from 30 horses. PROCEDURE: Forelimbs were obtained from horses in an abattoir. Equine digital veins were carefully removed from distal portions of the forelimbs. Rings of dissected EDVs were mounted in 5-mL organ baths to record isometric tension in the presence of various beta3-AR agonists (SR 58611A, ZD 2079, and ZM 215001). RESULTS: In intact EDVs, isoprenaline, SR 58611A, ZD 2079, and ZM 215001 induced concentration-dependent relaxation. Isoprenaline and SR 58611A-induced relaxations were reduced or unaffected by nadolol, respectively. In intact EDVs, SR 58611A-induced relaxation was significantly reduced in the presence of 2 microM ZM 215001 (used as a beta3-AR antagonist). In endothelium-denuded EDVs or intact EDVs in the presence of a nitric oxide synthase inhibitor, isoprenaline and SR 58611A-induced relaxations were significantly decreased. The endothelium-independent relaxation to SR 58611A was significantly inhibited in the presence of ZM 215001. In endotoxin-treated EDV, isoprenaline- and SR 58611A-induced relaxations were significantly reduced. In these conditions, cycloheximide (a protein synthesis inhibitor) and ibuprofen (a cyclooxygenase inhibitor) restored the relaxant response to SR 58611A. CONCLUSIONS AND CLINICAL RELEVANCE: Beta3-adrenoceptors are functionally expressed in EDVs. Incubation in the presence of endotoxin, used as an in vitro model of laminitis, induced an alteration of beta-AR-mediated relaxations in EDVs, which could be the consequence of cyclooxygenase induction and subsequent prostanoid production.  相似文献   

Spatial Distribution of Ambrosia-Beetle Catches: A Possibly Useful Knowledge to Improve Mass-Trapping     

Jean-Claude Grégoire  Frédéric Piel  Michel De Proft  Marius Gilbert 《Integrated Pest Management Reviews》2001,6(3-4):237-242

Several species of ambrosia beetles (Coleoptera: Scolytidae) have recently started attacking standing, living beeches (Fagus sylvatica) in southern Belgium. In 2001, 1.3 million m³ of apparently healthy trees were struck. So far the outbreak has been limited to the Ardenne, and partly the Gaume, areas, and Brussels has been untouched. The city of Brussels is surrounded by a vast 4300 ha forest, mainly planted with beech, the Forêt de Soignes, of invaluable ecological and recreational value, of which 1600 ha belong to the regional authorities. In the spring 2001, these latter commissionned a study to assess the new threat to the forest. A 500 m×500 m grid of small traps, baited with ethanol and lineatin, was deployed over the regional part of the forest. The main species caught were Trypodendron domesticum, Anisandrus dispar and, in high numbers, Xylosandrus germanus, an exotic species of Asian origin found for the first time in Belgium in 1994. Whilst there was a consistent homogeneity between catches within the same sites (2 traps/site, distant by 2–6 m), there were no spatial relationships between catches at larger distances for T. domesticum and A. dispar. For X. germanus, spatial autocorrelations were observed within distances of 2000 m, suggesting that this species has sufficient mobility to cover this range. The planning of the 2002 trapping campaign will take this information into account: the traps will be deployed within a smaller grid.  相似文献   

Multiscale computation of solar radiation for predictive vegetation modelling     

Christian Piedallu  Jean-Claude Gégout 《Annals of Forest Science》2007,64(8):899-909

The recent development of large environmental databases allow the analysis of the ecological behaviour of species or communities over large territories. Solar radiation is a fundamental component of ecological processes, but is poorly used at this scale due to the lack of available data. Here we present a GIS program allowing to calculate solar radiation as well locally as at large scale, taking into account both topographical (slope, aspect, altitude, shadowing) and global (cloudiness and latitude) parameters. This model was applied to the whole of France (540 000 km²) for each month of the year, using only a 50-m digital elevation model (DEM), latitude values and cloudiness data. Solar radiation measured from 88 meteorological stations used for validation indicated a R ² of 0.78 between measured and predicted annual radiation with better predictions for winter than for summer. Radiation values increase with altitude, and with slope for southern exposure, excepted in summer. They decrease with latitude, nebulosity, and slope for north, east, and west exposures. The effect of cloudiness is important, and reduces radiation by around 20% in winter and 10% in summer. Models of plant distribution were calculated for Abies alba, Acer pseudoplatanus, and Quercus pubescens, for France. The use of solar radiation improved modelling for the three species models directly or through the water balance variable. We conclude that models which incorporates both topographical and global variability of solar radiation can improve efficiency of large-scale models of plant distribution.  相似文献   

Effects of 80 years of forest management on landscape structure and pattern in the eastern Canadian boreal forest     

Dominique Boucher  Louis De Grandpré  Daniel Kneeshaw  Benoît St-Onge  Jean-Claude Ruel  Kaysandra Waldron  Jean-Martin Lussier 《Landscape Ecology》2015,30(10):1913-1929

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Levels of stilbene oligomers and astilbin in French varietal wines and in grapes during noble rot development     

Landrault N  Larronde F  Delaunay JC  Castagnino C  Vercauteren J  Merillon JM  Gasc F  Cros G  Teissedre PL 《Journal of agricultural and food chemistry》2002,50(7):2046-2052

Phenolics from grapes and wines can play a role against oxidation and development of atherosclerosis. Stilbenes have been shown to have cancer chemopreventive activity and to protect lipoproteins from oxidative damage. A method for the direct determination of stilbene oligomers (viniferin and pallidol) as well as astilbin in different types of wine using high-performance liquid chromatography with UV detection is described. In a survey of 21 commercial wines from the south of France, levels of pallidol and viniferin are reported for the first time in different types of wines. Viniferin was found to be present only in red and botrytized sweet white wines with levels between 0.1 and 1.63 mg/L; pallidol was not found in dry and sweet white wines but only in wines made by maceration with stems, with levels between 0.38 and 2.22 mg/L. Highest levels of astilbin were found in Egiodola (15.13 mg/L), Merlot (11.61 mg/L), and Cabernet Sauvignon (8.24 mg/L) for red wines and in Sauvignon (5.04 mg/L) for white varietal wines. Astilbin levels are highest for recent vintages, but pallidol is not found in older vintages. During noble rot development in Sauvignon or Sémillon grapes from the Sauternes area, levels of trans-astringin, trans-resveratrol, trans-piceid, and pallidol are quite low (<0.5 mg/kg of grapes). Viniferin and astilbin levels become optimum at 2 and 30 mg/kg, respectively, during spot grape and speckle grape stages.  相似文献   

Multi-temporal trajectories of landscape change explain forest biodiversity in urbanizing ecosystems     

Amy J. S. Davis  Jean-Claude Thill  Ross K. Meentemeyer 《Landscape Ecology》2017,32(9):1789-1803

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Biochemical and catalytic properties of three recombinant alcohol acyltransferases of melon. sulfur-containing ester formation, regulatory role of CoA-SH in activity, and sequence elements conferring substrate preference   总被引：1，自引：0，他引：1  

Lucchetta L  Manriquez D  El-Sharkawy I  Flores FB  Sanchez-Bel P  Zouine M  Ginies C  Bouzayen M  Rombaldi C  Pech JC  Latché A 《Journal of agricultural and food chemistry》2007,55(13):5213-5220

Alcohol acyltransferases (AAT) play a key role in the biosynthesis of ester aroma volatiles in fruit. Three ripening-specific recombinant AATs of cantaloupe Charentais melon fruit (Cm-AAT1, Cm-AAT3, and Cm-AAT4) are capable of synthesizing thioether esters with Cm-AAT1 being by far the most active. All proteins, as well as AAT(s) extracted from melon fruit, are active as tetramers of around 200 kDa. Kinetic analysis demonstrated that CoA-SH, a product of the reaction, is an activator at low concentrations and an inhibitor at higher concentrations. This was confirmed by the addition of phosphotransacetylase at various concentrations, capable of modulating the level of CoA-SH in the reaction medium. Site-directed mutagenesis of some amino acids that were specific to the Cm-AAT sequences into amino acids that were consensus to other characterized AATs greatly affected the selectivity of the original protein and the number of esters produced.  相似文献