Search results for "GRI"
showing 10 items of 10209 documents
Comparative study of the efficiency of buffer zones and harvest discarding on gene flow containment in oilseed rape. A modelling approach
2009
International audience; Oilseed rape (OSR) genes can escape fields in space via pollen and seeds and in time via volunteers resulting from seeds lost before or during oilseed rape harvests. Previous simulation studies and field observations showed that co-existence at the landscape level of contrasting OSR varieties such as genetically modified (GM) and non-GM varieties require costly measures that are difficult to implement, such as isolation distances between OSR fields and stringent volunteer control in all fields and road margins. In the present study, two local strategies, non-GM buffer zones aroundGMfields and discarding the harvest of boundary plants of non-GM fields, were tested in …
Fruit size in relation to competition for resources: A common model shared by two species and several genotypes grown under contrasted carbohydrate l…
2012
International audience; Fruit size is one important criterion of fruit external quality affecting consumer acceptance. The effects of seed number on fruit size in two fleshy fruits, grape and tomato, of different genotypes and grown under distinct carbohydrate availability levels were analyzed with a model. The two-parameter model described within-fruit resource competition and was able to well represent the commonly observed decrease in fresh weight per seed along with the increase in number of seeds, regardless of species, genotypes, and carbohydrate levels that were evaluated in this study. However, carbohydrate levels largely modified the correlation between seed number and fresh weight…
Sustainable production of fennel and dill by intercropping
2008
Intercropping is claimed to be one of the most significant cropping techniques in sustainable agriculture, and much research and many reviews attribute to its utilization a number of environmental benefits, from promoting land biodiversity to diversifying agricultural outcome. In this sense, intercropping is thought to be a useful means of minimizing the risks of agricultural production in many environments, including those typical of under-developed or marginal areas. In order to validate this hypothesis in a representative area of the semiarid Mediterranean environment, we evaluated the possibility of growing dill and fennel, both belonging to the family Apiaceae, in temporary intercroppi…
Nonchemical weeding of medicinal and aromatic plants
2013
International audience; Medicinal and aromatic plants are major crops of domestic and industrial interest. Medicinal and aromatic plants are increasingly organically grown to enhance profitability. However, the presence of weeds may lead to a decrease in both yield and quality. Therefore, nonchemical methods of weed control are needed. In this study, mechanical weeding, flaming, stale seedbed, and biodegradable mulch were tested from 2003/2004 to 2006/2007 on coriander, fennel, and psyllium. Biomass and seed yield were measured. The biomass of weeds remaining at harvest was also measured. Results show a high sensitivity of coriander, fennel, and psyllium crops to the presence of weeds. Stal…
History of chemical weeding from 1944 to 2011 in France: Changes and evolution of herbicide molecules
2012
International audience; Herbicide development in France has been analysed from a historical and agronomical perspective. A database was built up from data collected from the archives of the Ministry of Agriculture Food and Fisheries and from French phytosanitary compendia edited since 1961 by the Association de Coordination Technique Agricole. Only herbicides used in cultivated areas were retained. The first organic synthetic herbicides were registered on cereals after the Second World War. Since 1944, a total of 225 herbicidal active ingredients have been registered in France. The number of active ingredients regularly increased with a maximum of 138 in 2002; 104 were still authorized in 2…
Pseudomonas salomonii sp. nov., pathogenic on garlic, and Pseudomonas palleroniara sp. nov., isolated from rice
2002
International audience; A total of 26 strains, including 15 strains isolated from garlic plants with the typical symptoms of 'Café au lait' disease and 11 strains isolated from diseased or healthy rice seeds and sheaths infested by Pseudomonas fuscovaginae, were compared with 70 type or reference strains of oxidase-positive pathogenic or non-pathogenic fluorescent pseudomonads. The strains were characterized by using a polyphasic taxonomic approach. Numerical taxonomy of phenotypic characteristics showed that the garlic and rice strains were related to each other. However, they clustered into separate phenons, distinct from those of the other strains tested, and were different in several nu…
Pine-oil increases spray retention by oats
2003
Les effets de l'huile de pin a base d'alcools monoterpeniques (Pine-oil), d'un tensioactif nonylphenol, et d'huile de colza methylee (Em-MRO) sur la tension de surface dynamique de l'eau, la retention de pulverisations par l'avoine, l'angle de contact de gouttelettes d'eau, et la penetration foliaire du [ 14 C]2,4-D-dimethylamine dans l'avoine ont ete evalues. Pine-oil et l'huile de pin emulsifiee (Em-pine-oil) produisent les chutes de tension de surface dynamique les plus rapides et les niveaux de retention les plus eleves. Pine-oil et Em-pine-oil montrent un effet limite sur l'angle de contact alors que le surfactant l'augmentait grandement. En consequence le mode d'action des alcools mon…
Modelling vertical and lateral seed bank movements during mouldboard ploughing
2000
Abstract The vertical distribution of weed seeds in the soil is of fundamental importance because seedling emergence depends on seed depth. The lateral displacement of the earth during mouldboard ploughing contributes to the dispersal of the weeds inside the tilled field. In order to model vertical and lateral seed displacements during ploughing, an existing model describing soil particle movements for different ploughing characteristics (depth and width) and soil structures was tested on a multilocal field trial. The trials were carried out in 1996 and 1997 and comprised two soil textures and three soil structures; tillage was performed with a mouldboard plough at varying ploughing widths …
Detection and Characterization of Wolbachia Infections in Natural Populations of Aphids: Is the Hidden Diversity Fully Unraveled?
2011
Copyright © 2011 Augustinos et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Aphids are a serious threat to agriculture, despite being a rather small group of insects. The about 4,000 species worldwide engage in highly interesting and complex relationships with their microbial fauna. One of the key symbionts in arthropods is Wolbachia, an a-Proteobacterium implicated in many important biological processes and believed to be a potential tool for biological control. Aphids were thought not to harbour W…
Phytotoxicity and metabolism of chlortoluron in two wheat varieties
1985
Abstract Varietal susceptibility of winter wheat to chlortoluron, 1-(3-chloro-4-methylphenyl)-3,3 dimethylurea, has been studied in two varieties, Corin (susceptible) and Clement (tolerant). After a 24-hr root absorption of the herbicide, phytotoxicity was estimated from growth measurements. When administered at 12 to 96 μM concentrations, the herbicide reduced the growth of both varieties. A significant selective effect was found at 96 μM. Measurements of chlorophyll fluorescence-induction kinetics allowed to discriminate between the two varieties treated with 12 to 48 μM chlortoluron. The metabolism of chlortoluron was studied following absorption of 24 μM solutions. Both varieties produc…