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Since 2012, coffee leaf rust, a disease caused by the fungus Hemileia vastatrix, has been responsible for major epidemics of arabica coffee cultivation in all Central American countries. That year, about 20% of the production in this region was lost and the death of branches or even coffee plants caused significant secondary production losses in the following years. As coffee production provides many employments in Central America, these epidemics have led to a major social crisis. To prevent future epidemics, the PROCAGICA programme (Programa Centroamericano para la Gestión de la Roya del Café), initiated in 2016, with funding from the European Union, aims to implement measures such as the creation of a regional warning network, based on improved national systems, including a prognostic component based on weather variables. In most prediction models already available for this disease, meteorological variables are considered over long periods of time to explain indicators such as incidence reflecting disease progression but also host growth.In this thesis we hypothesized that it is possible to forecast epidemic growth by modelling different stages of the fungal development, each determined by complex combinations of microclimatic variables acting at different periods (times and durations). To better understand the functioning of the pathosystem and thus define the variables to be predicted, we first described the causal relationships existing between the phenology of arabica coffee, the development of coffee leaf rust and their environment in agroforestry systems. Through the use of structural equation modelling, the controversial overall effect of shading on the disease was explained as the result of antagonistic effects on colonization and sporulation stages, depending on the type of shading. This analysis also highlighted the strong interaction between rust and coffee growth. We therefore decided to avoid working on indicators such as incidence but rather to construct three models of symptoms and signs onset ...

International audience ; This chapter aims to question the policies that were jointly pursued by France towards the populations of Oceania, newly conquered, between 1840 and 1880. These policies differentiate according to the populations encountered, Tahitians, Marquesans, Kanak, because of the context in which they are found, the "racial" characteristics that French officials attribute to them or the power relations established locally with the chiefdoms and the new European competitors in the process of settling in the region. In this complicated context, the Tahitians were granted French citizenship in 1880 while the Kanaks were granted the status of French non-citizens and consequently the repressive regime of the indigénat like the vast majority of the indigenous peoples of the colonial Empire. ; Ce chapitre vise à interroger les politiques qui furent conjointement menées par la France à l'égard des populations de l'Océanie, nouvellement conquises, entre 1840 et 1880. Ces politiques opèrent des différentiations en fonction des populations rencontrées, Tahitiens, Marquisiens, Kanak, du fait du contexte dans lequel elles se trouvent, des caractéristiques « raciales » que les officiels français leur attribuent ou encore des rapports de force instaurés localement avec les chefferies et les nouveaux compétiteurs européens en voie d'installation dans la région. Dans ce contexte compliqué, les Tahitiens se voient accorder la citoyenneté française en 1880 tandis que les Kanak sont placés sous le statut de Français non citoyen comme la grande majorité des indigènes de l'Empire colonial et par voie de conséquence le régime répressif de l'indigénat.

Since 2012, coffee leaf rust, a disease caused by the fungus Hemileia vastatrix, has been responsible for major epidemics of arabica coffee cultivation in all Central American countries. That year, about 20% of the production in this region was lost and the death of branches or even coffee plants caused significant secondary production losses in the following years. As coffee production provides many employments in Central America, these epidemics have led to a major social crisis. To prevent future epidemics, the PROCAGICA programme (Programa Centroamericano para la Gestión de la Roya del Café), initiated in 2016, with funding from the European Union, aims to implement measures such as the creation of a regional warning network, based on improved national systems, including a prognostic component based on weather variables. In most prediction models already available for this disease, meteorological variables are considered over long periods of time to explain indicators such as incidence reflecting disease progression but also host growth.In this thesis we hypothesized that it is possible to forecast epidemic growth by modelling different stages of the fungal development, each determined by complex combinations of microclimatic variables acting at different periods (times and durations). To better understand the functioning of the pathosystem and thus define the variables to be predicted, we first described the causal relationships existing between the phenology of arabica coffee, the development of coffee leaf rust and their environment in agroforestry systems. Through the use of structural equation modelling, the controversial overall effect of shading on the disease was explained as the result of antagonistic effects on colonization and sporulation stages, depending on the type of shading. This analysis also highlighted the strong interaction between rust and coffee growth. We therefore decided to avoid working on indicators such as incidence but rather to construct three models of symptoms and signs onset ...

Since 2012, coffee leaf rust, a disease caused by the fungus Hemileia vastatrix, has been responsible for major epidemics of arabica coffee cultivation in all Central American countries. That year, about 20% of the production in this region was lost and the death of branches or even coffee plants caused significant secondary production losses in the following years. As coffee production provides many employments in Central America, these epidemics have led to a major social crisis. To prevent future epidemics, the PROCAGICA programme (Programa Centroamericano para la Gestión de la Roya del Café), initiated in 2016, with funding from the European Union, aims to implement measures such as the creation of a regional warning network, based on improved national systems, including a prognostic component based on weather variables. In most prediction models already available for this disease, meteorological variables are considered over long periods of time to explain indicators such as incidence reflecting disease progression but also host growth.In this thesis we hypothesized that it is possible to forecast epidemic growth by modelling different stages of the fungal development, each determined by complex combinations of microclimatic variables acting at different periods (times and durations). To better understand the functioning of the pathosystem and thus define the variables to be predicted, we first described the causal relationships existing between the phenology of arabica coffee, the development of coffee leaf rust and their environment in agroforestry systems. Through the use of structural equation modelling, the controversial overall effect of shading on the disease was explained as the result of antagonistic effects on colonization and sporulation stages, depending on the type of shading. This analysis also highlighted the strong interaction between rust and coffee growth. We therefore decided to avoid working on indicators such as incidence but rather to construct three models of symptoms and signs onset ...

International audience ; This chapter aims to question the policies that were jointly pursued by France towards the populations of Oceania, newly conquered, between 1840 and 1880. These policies differentiate according to the populations encountered, Tahitians, Marquesans, Kanak, because of the context in which they are found, the "racial" characteristics that French officials attribute to them or the power relations established locally with the chiefdoms and the new European competitors in the process of settling in the region. In this complicated context, the Tahitians were granted French citizenship in 1880 while the Kanaks were granted the status of French non-citizens and consequently the repressive regime of the indigénat like the vast majority of the indigenous peoples of the colonial Empire. ; Ce chapitre vise à interroger les politiques qui furent conjointement menées par la France à l'égard des populations de l'Océanie, nouvellement conquises, entre 1840 et 1880. Ces politiques opèrent des différentiations en fonction des populations rencontrées, Tahitiens, Marquisiens, Kanak, du fait du contexte dans lequel elles se trouvent, des caractéristiques « raciales » que les officiels français leur attribuent ou encore des rapports de force instaurés localement avec les chefferies et les nouveaux compétiteurs européens en voie d'installation dans la région. Dans ce contexte compliqué, les Tahitiens se voient accorder la citoyenneté française en 1880 tandis que les Kanak sont placés sous le statut de Français non citoyen comme la grande majorité des indigènes de l'Empire colonial et par voie de conséquence le régime répressif de l'indigénat.

De la « légalisation » de la violence en contexte colonial. Le régime de l'indigénat en question
Isabelle Merle
En prenant appui sur une enquête en cours, cette contribution propose d'examiner à nouveaux frais ce qu'on a appelé le « régime de l'indigénat », pilier essentiel des politiques répressives menées par la France dans les colonies à l'encontre des populations assujetties. L'enjeu, ici, est d'éclairer de façon approfondie les contradictions que suscitent ce régime répressif en France métropolitaine ainsi que d'en analyser les modalités pratiques dans les différents territoires coloniaux, modalités extrêmement diversifiées et instables qui restent relativement méconnues. Afin de dépasser le registre des seules prescriptions, il s'est agi de mettre en lumière une « situation coloniale » singulière, celle de la Nouvelle-Calédonie, où le régime de l'indigénat a été appliqué localement dans toute sa rigueur jusqu'à 1946, sur une population Kanak particulièrement vulnérable, minoritaire et refoulée dans des réserves. A travers ce cas-limite, il s'agit d'apprécier concrètement les effets et les limites d'une « violence coloniale » telle qu'elle est organisée, au quotidien, par le régime de l'indigénat.