Search results for "crop"
showing 10 items of 3837 documents
Degradation of aromatic compounds through the β-ketoadipate pathway is required for pathogenicity of the tomato wilt pathogenFusarium oxysporumf. sp.…
2012
Plant roots react to pathogen attack by the activation of general and systemic resistance, including the lignification of cell walls and increased release of phenolic compounds in root exudate. Some fungi have the capacity to degrade lignin using ligninolytic extracellular peroxidases and laccases. Aromatic lignin breakdown products are further catabolized via the β-ketoadipate pathway. In this study, we investigated the role of 3-carboxy-cis,cis-muconate lactonizing enzyme (CMLE), an enzyme of the β-ketoadipate pathway, in the pathogenicity of Fusarium oxysporum f. sp. lycopersici towards its host, tomato. As expected, the cmle deletion mutant cannot catabolize phenolic compounds known to …
Land use classification from multitemporal Landsat imagery using the Yearly Land Cover Dynamics (YLCD) method
2011
Abstract Several previous studies have shown that the inclusion of the LST (Land Surface Temperature) parameter to a NDVI (Normalized Difference Vegetation Index) based classification procedure is beneficial to classification accuracy. In this work, the Yearly Land Cover Dynamics (YLCD) approach, which is based on annual behavior of LST and NDVI, has been used to classify an agricultural area into crop types. To this end, a time series of Landsat-5 images for year 2009 of the Barrax (Spain) area has been processed: georeferenciation, destriping and atmospheric correction have been carried out to estimate NDVI and LST time series for year 2009, from which YLCD parameters were estimated. Then…
Microclimat, eau et production
1990
It is generally known that the whole of climatic factors affects directly the principal biological functions and the processes influencing crop yield. However, the control of these factors remains very difficult. Research is carried out adapting different crops to the average daily climatic characteristics and to their seasonal evolution instead of modifying the crops genetically and physiologically. Since all times the control of the factor water, not from rainfall but from irrigation, gives possibilities to modify directly the characteristics of the microclimate in the plant canopy.
Diuron mineralisation in a Mediterranean vineyard soil: impact of moisture content and temperature
2010
BACKGROUND: The diuron-mineralising ability of the microbiota of a Mediterranean vineyard soil exposed each year to this herbicide was measured. The impact of soil moisture and temperature on this microbial activity was assessed. RESULTS: The soil microbiota was shown to mineralise diuron. This mineralising activity was positively correlated with soil moisture content, being negligible at 5% and more than 30% at 20% soil moisture content. According to a double Gaussian model applied to fit the dataset, the optimum temperature/soil moisture conditions were 27.9 °C/19.3% for maximum mineralisation rate and 21.9 °C/18.3% for maximum percentage mineralisation. The impact of temperature and soil…
Evidence for 2,4-D mineralisation in Mediterranean soils: impact of moisture content and temperature
2009
BACKGROUND: The 2,4-D degradation ability of the microbiota of three arable Mediterranean soils was estimated. The impact of soil moisture and temperature on 2,4-D degradation was investigated. RESULTS: The microbiota of the three soils regularly exposed to 2,4-D were able rapidly to mineralise this herbicide. The half-life of 2,4-D ranged from 8 to 30 days, and maximum mineralisation of 14C-2,4-D ranged from 57 to 71%. Extractable 14C-2,4-D and 14C-bound residues accounted for less than 1 and 15% respectively of the 14C-2,4-D initially added. The highest amounts of 14C-2,4-D bound residues were recorded in the soil with the lowest 2,4-D-mineralising ability. Although all three soils were a…
Errors and uncertainties introduced by a regional climate model in climate impact assessments: example of crop yield simulations in West Africa
2015
16 pages; International audience; The challenge of estimating the potential impacts of climate change has led to an increasing use of dynamical downscaling to produce fine spatial-scale climate projections for impact assessments. In this work, we analyze if and to what extent the bias in the simulated crop yield can be reduced by using the Weather Research and Forecasting (WRF) regional climate model to downscale ERA-Interim (European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis) rainfall and radiation data. Then, we evaluate the uncertainties resulting from both the choice of the physical parameterizations of the WRF model and its internal variability. Impact assessments w…
Spatial and temporal stability of weed populations over five years
2000
Abstract The size, location, and variation in time of weed patches within an arable field were analyzed with the ultimate goal of simplifying weed mapping. Annual and perennial weeds were sampled yearly from 1993 to 1997 at 410 permanent grid points in a 1.3-ha no-till field sown to row crops each year. Geostatistical techniques were used to examine the data as follows: (1) spatial structure within years; (2) relationships of spatial structure to literature-derived population parameters, such as seed production and seed longevity; and (3) stability of weed patches across years. Within years, densities were more variable across crop rows and patches were elongated along rows. Aggregation of …
Efficacy and foliar absorption of flupyrsulfuron-methyl and prosulfocarb applied alone or in mixture on Lolium multiflorum and wheat
2001
Des melanges de flupyrsulfuron-methyle et de prosulfocarbe concus pour ameliorer la lutte contre Lolium multiflorum Lam. dans le ble (Triticum aestivum L.) ont ete etudies grâce a des essais biologiques sur plantes entieres et a des etudes de penetration foliaire. Dans les essais biologiques, le flupyrsulfuron-methyle et le prosulfocarbe etaient appliques a 6-7 doses, seuls ou en melange dans les rapports 1:400, 1:40 et 1:4 (p/p). Les courbes de reponse etaient ajustees au moyen de modeles logistiques et l'action conjuguee etait evaluee par la methode des isoboles. Dans les essais biologiques conduits en serre sur L. multiflorum, l'action conjuguee des melanges montrait une additivite de do…
Monitoring Cropland Phenology on Google Earth Engine Using Gaussian Process Regression
2021
Monitoring cropland phenology from optical satellite data remains a challenging task due to the influence of clouds and atmospheric artifacts. Therefore, measures need to be taken to overcome these challenges and gain better knowledge of crop dynamics. The arrival of cloud computing platforms such as Google Earth Engine (GEE) has enabled us to propose a Sentinel-2 (S2) phenology end-to-end processing chain. To achieve this, the following pipeline was implemented: (1) the building of hybrid Gaussian Process Regression (GPR) retrieval models of crop traits optimized with active learning, (2) implementation of these models on GEE (3) generation of spatiotemporally continuous maps and time seri…
205th ENMC International Workshop: Pathology diagnosis of idiopathic inflammatory myopathies Part II 28-30 March 2014, Naarden, The Netherlands.
2015
The idiopathic inflammatory myopathies (IM) are a heterogeneous group of diseases and diagnosis often necessitates a muscle biopsy. Five main entities are recognized: (1) dermatomyositis (DM); (2) polymyositis (PM); (3) necrotizing autoimmune myopathy (NAM); (4) sporadic inclusion body myositis (IBM); and (5) non-specific myositis. Other entities include granulomatous myopathy, macrophagic myofasciitis, and eosinophilic fasciitis (Shulman's syndrome). The pathological classification and subsequent identification of disease subgroups are extremely important for assessing treatment options and prognosis in the individual patient, yet classification criteria have not been standardized and vali…