ISHS Acta Horticulturae 761: XXVII International Horticultural Congress - IHC2006: International Symposium on Advances in Environmental Control, Automation and Cultivation Systems for Sustainable, High-Quality Crop Production under Protected Cultivation
BOTRYTIS SPORES TRANSFER CHARACTERISATION AND MODELLING IN A ROSE GREENHOUSE |
| Authors: | T. Boulard, M. Chave, H. Fatnassi, J.C. Roy, I. Lee |
| Keywords: | greenhouse, model, rose, Botrytis, spores |
| Abstract:
Fungal pathogens and especially grey mould are among the most virulent bioagressors of protected cultivations. Inside greenhouse climate marked by high air temperature and humidity content is highly favourable to the development of B. cinerea and its control is further complicated by the absence of commercial resistant varieties and a limited arsenal available for chemical control. This fungus is very prolific and has a rapid asexual reproductive cycle marked by an abundant spore production which is easily transported by air movements and may contribute to the development of explosive epidemics. The present study will focus on the determination of the balance of the spores inside a rose greenhouse in order to determine if the spores are in majority produced inside or outside the greenhouse and to predict their displacements, deposition and interception by the crop cover. Two major approaches have been undertaken: 1) An experimental one, based on the Botrytis spore balance of the finite greenhouse volume, spore concentration being considered as a particular species which is transported by air in the same way as heat, CO2, water vapour or any tracer gas, spore balance being performed in the same way as for these species; and, 2) A modelling approach, based on the development of specific module associated to a conventional Computational Fluid Dynamics model, to model, compute and solve the transport and deposition of B. cinerea spores on vegetation rows, soil and insect-proof nets. First experimental results are presented for young rose crop cultivation. It is shown that the origin of the inoculums is predominantly external but that internal spore production increases as the plantation grows old. These experimental data are used for the validation of the CFD based spore transfer model and, once validated the CFD model of spore’s transfer is used to examine the distribution of the concentration and the deposition of spores inside the greenhouse. Various improvements aiming at spore control are deduced and discussed. | |
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