Development of a ground based real-time remote sensing system for detecting at an early stage foci of yellow rust and septoria leaf blight in incubation.The methodology is based upon differences in reflectance and fluorescence properties and leaf temperature variations between healthy and diseased plants. The spectral signatures linked to drought stress or nitrogen deficiency will be taken into consideration. The signals will be treated for spatially variable fungicide apllication. Our specific task is to produce various levels of disease pressure and abiotic stresses under controled environmental conditions and to perform epidemic modelling for yield loss assessement according to disease levels at various growth stages.