Nathalie Colbach

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ABSTRACT Wheat was assessed at four crop growth stages for take-all (Gaeumannomyces graminis var. tritici) in a series of field trials that studied the effects of five wheat management practices: sowing date, plant density, nitrogen fertilizer dose and form, and removal/burial of cereal straw. An equation expressing disease level as a function of degree(More)
BACKGROUND, AIM AND SCOPE Agricultural landscapes comprise cultivated fields and semi-natural areas. Biological components of these compartments such as weeds, insect pests and pathogenic fungi can disperse sometimes over very large distances, colonise new habitats via insect flight, spores, pollen or seeds and are responsible for losses in crop yield (e.g.(More)
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(More)
Neutral landscape models are not frequently used in the agro-nomical domain, whereas they would be very useful for studying given agro-ecological or physical processes. Contrary to ecological neutral landscape models, agricultural models have to represent and manage geometrical patches and thus should rely on tessellation methods. We present a three steps(More)
Genetically-modified (GM) crops increased their share in EU agriculture, so the adventitious presence of GM varieties in non-GM seeds and crops has become an issue and poses the problem of their coexistence with conventional and organic crops. Therefore, there is a need to propose appropriate measures at the farm and regional levels to minimize adventitious(More)
IPSIM (Injury Profile SIMulator) is a generic modelling framework presented in a companion paper. It aims at predicting a crop injury profile as a function of cropping practices and abiotic and biotic environment. IPSIM's modelling approach consists of designing a model with an aggregative hierarchical tree of attributes. In order to provide a proof of(More)
In Europe, the current decrease of herbicide application increases and diversifies weed flora in crops. As a consequence, there is an increase in the number of pests that use weeds to spread. This change is a major threat to crop production. For instance broomrape—Phelipanche ramosa—is an obligate parasite of dicotyledonous species that reduces crop yield(More)
Reducing pesticide use in agriculture is necessary to preserve natural resources. However, pest control without pesticides is a challenging issue. In particular, weed infestation may cause severe losses of crop yield. Weeds have been traditionally managed solely at the field level. However, larger scales must be considered because invasive and(More)
The production of genetically-modified (GM) crops has increased rapidly over the last 10 years. The possibility of GM crops mixing with conventional or organic crops is becoming a problem and estimating the adventitious presence of GM seeds into conventional crop harvests presents a challenge. In this study we used outputs from a previously developed(More)