Plot schemes to reduce epidemics Inter- and intra-plot spatial organization and spatialization of crop protection resources have long been overlooked, even though these are key elements for pest and disease control. Because of its moderate dispersal, the banana weevil is a good example for studying the effect of the spatial organization of cropping systems on its epidemiology. CIRAD researchers have thus developed a spatially explicit model, COSMOS, which simulates the insect’s movements, reproduction and mortality in interaction with banana trees, crop residues, cover plants and pheromone traps. The COSMOS model can be used to optimize trapping, and proposes landscape plot patterns that hamper the development of banana weevil populations.
Towards simulation of the overall ecological functioning of banana plantations Current agroecological research shows that it is essential to design new agroecosystem study methods in order to be able to monitor the ecological processes occurring in more complex cropping systems. In this setting, interactions between
plants and communities of pests, beneficial organisms and non-productive organisms are crucial. Researchers are thus prompted to combine standard agronomic tools (crop models) with new formalisms, such as food web models, which can be used to simulate many complex interactions. These new tools should make it possible to predict performances in terms of production and emerging properties of different communities in banana plantations; this includes their stability and resilience. Such tools allow the simulation of the emerging properties of cropping systems, especially the one including pest and disease control and feedback of the communities on soil properties. The prospects of applying these ecological mechanisms are especially promising in the case of plantain-based cropping systems.
Contact
Philippe Tixier, Banana, Plantain and Pineapple Cropping Systems (UPR)
Tixier P., Malézieux E., Dorel M., 2007. A modelbased approach to maximise gross income by selection of banana planting date. Biosystems Engineering, 6: 471-476. Tixier P., Malézieux E., Dorel M., Wery J., 2008. SIMBA: a comprehensive model for evaluation and prototyping of banana-based cropping systems. Agricultural Systems, 97: 139-150.
For further information
A special feature of this model is that it accounts for changes in the plant population structure, which becomes less homogeneous over cropping cycles: this key point affects all the system dynamics. Moreover, the SIMBA model includes plant-parasitic nematode dynamics and the interactions with plant growth, soil structure and nematicide treatments; this is a major element in simulating the agroenvironmental performance (sustainability) of simulated banana plantations. Finally, the model can be used for in-depth studies on certain ecological mechanisms, such as host-parasite relationships, and for developing and optimizing new control strategies, such as crop rotations or notill systems based on cover crops.
A cropping system integrating cover vegetation (grass). The SIMBA model simulates nitrogen flows in this system and helps optimize sowing date, cover mowing date and fertilizer application date, thus minimizing competition with the banana trees
© R. Achard/CIRAD
22 . CIRAD 2008
Tixier P., Salmon S., Chabrier C., Quénéhervé P., 2008. Modelling pest dynamics of new crop cultivars: The FB920 banana with the Helicotylenchus multicinctus-Radopholus similis nematode complex in Martinique. Crop Protection, 27: 1427-1431.
Crop protection—CIRAD organized the first ENDURE network conference
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ENDURE, the EU-funded Network of Excellence on diversifying crop protection, held its first international conference on this topic, with over 120 talks presented, from 13 to 15 October in southern France. CIRAD organized this event and 27 CIRAD scientists presented their results. A special workshop was focused on links the network intends to make with research teams in developing countries. ENDURE was launched in 2007 and is coordinated by INRA. It brings together over 300 researchers from 18 European institutions. It is aimed at structuring fundamental and applied research forces in order to develop innovative crop protection strategies that are compatible with sustainable development (around 60% of all pesticides have been withdrawn from the European market over the last 10 years). It intends to become the world leader in the field of crop protection strategies. CIRAD is substantially involved
in this network through its long experience in developing countries, and several of its research units are directly involved in network projects. It is participating especially in a study on tomato and in a horticulture thematic project, while coordinating a case study on banana via one of its research units. As part of the ENDURE executive committee, CIRAD is specifically in charge of relations with developing countries and communications.
Contact
Jean-Louis Sarah, Biological Systems Department
For further information International conference:»Diversifying crop protection», 12-15 October 2008, La Grande-Motte, France. ENDURE: European Network for the Durable Exploitation of Crop Protection Strategies. www.endurenetwork.eu