CIRAD, UMR CMAEE
Les plantes de couverture peuvent favoriser la régulation naturelle des ravageurs en permettant aux populations de prédateurs d’augmenter. Mais elles peuvent aussi modifier considérablement le régime alimentaire de ces prédateurs. Une équipe du Cirad vient d’en apporter la preuve en identifiant, grâce à la technique du métabarcoding ADN, les proies ingérées par les prédateurs du charançon du bananier dans les plantations de la Martinique. Une première dans l’utilisation in situ de cette technique d’analyse de l’ADN.
The way rice is cooked determines its flavour and consistency, two characteristics that are highly sought after among consumers. Hence the idea of modelling the transfers and reactions that occur during cooking, so as to predict and control its texture. A team from CIRAD has developed a rice cooking model, which assimilates the grain to a sphere and includes water transfers, deformation and starch gelatinization.
Large trees play a vital role in the carbon balance of logged forests. This was the conclusion drawn by a study in the Brazilian Amazon by CIRAD and EMBRAPA. By sparing large trees, reducing logging intensity and being paid compensation for doing so, logging firms can greatly improve their sustainability. An additional benefit is the improved functioning of the whole forest ecosystem, for which these trees are of major ecological value.
Researchers from CIRAD and their partners recently built several core collections of Coffea canephora coffee trees, based on an analysis of the genetic diversity of the species. These small-scale collections, which are easier to manage and maintain than the vast collections currently held by research centres, will be valuable tools for breeders, and should enable them to address the new issues now facing coffee producers, be they related to pests and diseases or to climate change.
Zones identified as biodiversity hotspots can also be of use for other ecosystem services, such as carbon sequestration, water conservation and landscape quality. This is not necessarily the case for zones with large amounts of carbon, which have fewer advantages in terms of other ecosystem services. These were the conclusions drawn from a study in Costa Rica by a team from CIRAD, CIFOR and CATIE. The results could have repercussions for the choice of zones to be protected under initiatives aimed at mitigating emissions caused by deforestation, such as REDD.
The pathogenic bacterium Xanthomonas albilineans was thought to multiply solely within the sugarcane vascular system. However, researchers from CIRAD and the IRD recently demonstrated that it can also invade other leaf and stalk tissues, particularly those cells that store sucrose. It is the first time that such a characteristic has been described in a plant pathogenic bacterium. The discovery opens up new prospects as regards bacterial invasion strategies.
In the Lake Alaotra region of Madagascar, farms face a number of risks. What is their capacity to innovate and adapt? On what criteria can we base analyses of their vulnerability, resilience and sustainability? Researchers from CIRAD have chosen a number of indicators that allow them to assess and analyse these parameters. This is a step along the way to building a World Agriculture Watch.
Soil erosion is a major problem in the Sahel. On sandy soils, wind erosion can also damage fields of millet, the region's main food crop. To limit these adverse effects and maintain soil fertility, millet stalks can be left in the field after harvesting. But how does this practice affect millet pest survival? Researchers from CIRAD and their partners recently studied those effects at two sites in Niger.
In Guadeloupe, the bacterium Xanthomonas albilineans, which causes sugarcane leaf scald, is transmitted by air and colonizes the leaf surface before spreading within the tissues. A team from CIRAD recently demonstrated that variety has a determining influence on this early infection stage and on the subsequent evolution of the disease.
Researchers from CIRAD and their Senegalese partners have successfully tested a participatory method for drafting natural resource policy, which combines role-play and simulation board games. It allows farmers to test their proposals for sustainable development, without any preconceived scientific or political ideas. The aim is to allow local know-how to be expressed, so as to derive original solutions suited to natural resource use in the uncertain climatic conditions of the Sahel.
Rice breeders at CIRAD use a male sterility gene to facilitate crossing within their improvement programmes. They recently identified its position in the genome and its function, using the crop's genome resources, which are now well developed.
In Réunion, researchers from CIRAD and their Spanish counterparts have helped develop a system for the mass trapping of female fruit flies of two species, Ceratitis rosa and C. capitata, which cause significant damage. The system, which combines a trap, a substance that attracts the females and a small amount of insecticide, is easy to use and as effective as conventional control methods, but without the drawbacks. It is ideal for protecting citrus orchards at medium and high altitudes.
