Search results for " Fisheries"
showing 10 items of 1031 documents
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…
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 …
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…
The beneficial rhizosphere : a necessary strategy for microplant production
2000
Society's expectation that plant production systems will become more compatible with the environment requires the development of an agriculture with low chemical inputs. With microplants, this can be achieved successfully by the introduction of beneficial microorganisms, particularly those developing in the rhizosphere. Inoculation with mycorrhizal fungi has provided a wide range of examples of the usefulness of this technology. Recent results indicate that this application could be improved by combining mycorrhizal inoculation with other soil microbes with complementary beneficial effects. It is proposed that multimicrobial biotization is a valuable development for microplant technology.
Climate vs grapevine pests and diseases worldwide: The first results of a global survey
2016
<p class="Abstract"><strong>Aim:</strong> This paper aimed to address the relationship between grapevine disease, pest occurrences and climate. The extremely large extension of viticulture worldwide offers the possibility to evaluate the impacts of climate variability on many aspects of the grape growing system. For this, we initiated a global survey to retrieve the most important diseases and pests in many grape growing regions worldwide and to identify the risk of exposure to pests and diseases of viticulture as a function of climate.</p><p class="Abstract"><strong>Methods and results:</strong> Based on the answer of respondent about the main repo…
Soil and fertilizer phosphorus : effects on plant P supply and mycorrhizal development
2005
Plants require adequate P from the very early stages of growth for optimum crop production. Phosphorus supply to the crop is affected by soil P, P fertilizer management and by soil and environmental conditions influencing P phytoavailability and root growth. Phosphorus uptake in many crops is improved by associations with arbuscular mycorrhizal fungi. Cropping system and long-term input of P through fertilizers and manures can influence the amount and phytoavailability of P in the system and the development of mycorrhizal associations. Optimum yield potential requires an adequate P supply to the crop from the soil or from P additions. Where early-season P supply is low, P fertilization may…
Use of chlorophyll fluorescence induction kinetics to study translocation and detoxication of DCMU-type herbicides in plant leaves
1984
Transient levels of the fluorescence induction rise were used to quantify partial photosynthesis inhibition by DCMU -type herbicides in whole leaves. Assays in different crop or weed species showed a good accuracy in measurements (generally, variation was lower than 5%). This technique was applied to the problem of varietal selectivity of wheat towards chlortoluron.
Priorities for research in soil ecology
2017
The ecological interactions that occur in and with soil are of consequence in many ecosystems on the planet. These interactions provide numerous essential ecosystem services, and the sustainable management of soils has attracted increasing scientific and public attention. Although soil ecology emerged as an independent field of research many decades ago, and we have gained important insights into the functioning of soils, there still are fundamental aspects that need to be better understood to ensure that the ecosystem services that soils provide are not lost and that soils can be used in a sustainable way. In this perspectives paper, we highlight some of the major knowledge gaps that shoul…