Search results for "Weed"
showing 10 items of 321 documents
Amino acids for parasitic weed management
2017
Prod 2017-322 SPE GESTAD INRA; International audience
Herbicide site specific spraying: use of simulations to study the impact of section width
2019
International audience; Site specific spraying is one way to reduce the amount of herbicide required to control weeds. The impact of boom section width was investigated by using simulated weed infestation maps with various weed coverage rates. Herbicide applications were simulated combining these virtual maps with various boom sections widths and various theoretical spray patterns. The objective was to quantify the herbicide reduction possibilities and potential under-application areas. Simulation derived results are analyzed using three indicators: i) the ratio between herbicide amount in the case of a targeted application and the amount deposited in the case of a full application, ii) the…
Toward a better prediction of in-field weed regulation by carabid beetles in European arable landscapes
2019
International audience; Arable agriculture is still highly reliant on herbicides to manage weeds. As part of the necessary shift towards a reduction in pesticide use, the regulatory effect of seed-eating carabid beetles on weeds has received increasing attention in agroecological research. While strong evidence points to carabids exerting a regulatory effect on certain weed species, it is difficult to predict whether a particular assemblage of carabid species will drive the function of weed seed predation in field conditions. There are also uncertainties about which key local and landscape-scale factors affect the function of weed seed predation. In this paper, we report on specific researc…
Species-specific prey choice of carabid beetles in European cereal fields
2017
National audience; Trophic interactions between species in agroecosystems provide key regulation ecosystem services and therefore also determine the dynamics, robustness and resilience of service provision. To achieve international goals of reducing application of pesticides without compromising key provisioning ecosystem services such as crop yield, recent research attaches importance to the biological control potential of carabid beetles. However, apart from feeding on pest species and weed seeds, carabids also consume non-pest prey (alternative prey) such as collembolans and earthworms, which can play a contradictory role in the efficacy of pest and weed control. Most carabids are descri…
Changing agricultural practices modifies the species and trait composition of the weed flora. A simulation study using a cropping system model
2013
International audience; Cropping systems change over time to adapt to socio-economical and environmental constraints and to profit from technological innovations. These changes can result in unexpected side-effects which are difficult to determine in fields. The objective of the present study was to use a cropping system model to evaluate the impacts of modified agricultural practices ex ante on weeds. The FLORSYS model quantifies the effect of crop succession, management techniques and climate on multi-specific weed dynamics over the years; it was parameterized with functional relationships predicting model parameters (e.g. pre-emergent seedling mortality) from species traits (e.g. seed ma…
Digital tools for a biomass prediction from a plant-growth model. Application to a weed control in wheat crop
2019
International audience; Weed control is essential for crop quality and yield. Usually, the main factors affectingdecision-making of farmers in weeding are based on the presence of certain weedvarieties and their density (plants/m2). However, the weed management at the scale ofthe crop cycle refers to other competition indicators, more reliable, such as plantbiomass or leaf area index (LAI). Classically, plant biomass measurements are obtainedby a destructive method of sampling, time consuming and it turns out to be unworkablein practice for farmers. This project proposes to study an innovative method of biomassevaluation which is based on the acquisition of plot images to determine the leaf…
Growth and reproduction responses of French invasive and North American native populations of common ragweed, Ambrosia artemisiifolia L. to defoliati…
2012
Enemy release and Evolution of Increased Competitive Ability hypotheses have been put forward to explain invasion success of introduced plant species. These hypotheses assume that the loss of natural enemies could induce an evolutionary change in plant defence and in resource allocation allowing the introduced plant populations to increase in vigour and fitness. To detect changes in functional traits following defoliation, we compared native and introduced populations of common ragweed, grown in a common garden environment. We compared six populations of Ambrosia artemisiifolia L., three from the North American native range and three from the French introduction range. We explored the effec…
Legumes and the environment
2017
Prod 2017-358a BAP GEAPSI INRA; International audience; The ability of legumes to fix atmospheric nitrogen gives them a crucial role in sustainable farming systems. Their presence can provide several other valuable ecological services. In Europe these assets have been neglected whilst developing highinput farming systems for maximizing yields. Diverse strategies are presented for maximizing ecological services provided by legumes in order to re-integrate them in cropping systems. Key words: Inputs, intercrop, ecological services, mineralization, weeds, N-fixation, value chain The second plenary session of the International Legume Society conference was dedicated to talks on “Legume and envi…
Weed flora evolution in direct seeding under cover systems
2018
Direct seeding under cover, by its emergent properties, raises new questions of research on weed communities. The absence of soil disturbance and the implementation of cover crops, modify all factors of conventional agriculture and lead to a complete change of habitat for and management of the weed flora. In addition, these systems allow the development of a certain number of animal communities that interact with one another and with plant communities and thus potentially promote the regulations expected in Agroecology. Finally, there is the issue of annual weed species diversity in systems where tillage is strongly reduced. This thesis, started in November 2017, has as main objective to pr…
Weed flora evolution in direct seeding under cover systems
2019
Since the beginning of agriculture, farmers have been working the soil to produce. With the apparition of mechanization (development of plow coupled to tractors in the early 20th century), this practice has intensified and widespread on all farms. However, in France, since the 2000s, more and more farmers are questioning the utility of working the soil to produce. A new form of agriculture has appeared; the direct seeding under cover which groups together a set of cropping systems that meet certain requirements: no tillage, maximum vegetation cover and diversified rotation. By its emergent properties, this new form of agriculture raises new questions of research that mobilize both agronomy …