• Aucun résultat trouvé

Performance of leaf wetness sensor used in winter wheat disease management


Academic year: 2021

Partager "Performance of leaf wetness sensor used in winter wheat disease management"


Texte intégral


Symposium "In-situ Environmental Monitoring and Policy" (U Ghent 26-27/05/2011)

Abdeslam Mahtour (amahtour@doct.ulg.ac.be)

Performance of leaf wetness sensor used in winter wheat disease management

A. Mahtour1, M. El Jarroudi1, L. Hoffmann2, B. Tychon1

1University of Liege, 185, Avenue de Longwy B-6700, Arlon, Belgium

2 Centre de Recherche Public - Gabriel Lippmann, Département Environnement et Agro-biotechnologies (EVA), 41 Rue du Brill, L-4422 Belvaux, Luxembourg.

Email : amahtour@doct.ulg.ac.be

Wetness on crop leaves has particular epidemiological significance because many fungal diseases affect plants only when free moisture is present on leaves. The leaf wetness sensor detects the presence of wetness on a leaf’s surface, enabling researchers and producers to forecast disease and protect plant canopies, and consequently to optimize fungicide application and often reduce environmental load. This research project aimed at better understanding the leaf wetness duration and its influence in winter wheat disease.

Measurement of surface wetness duration by three electronic flat-plate sensors (Model 237-Campbell Scientific, Inc) in wheat fields were compared with tactile and visual observations in replicated field experiments at the site of Arlon (Belgium) during the period May-July 2006 and April-July 2007. Performances of the sensor were evaluated against SWEB model outputs and visual observations of disease symptoms.

On the field, dew-onset and dry-off of wetness on leaves were observed visually (with a flash light for dew-onset) at 15-minute intervals. Each sensor was placed close the flag leaf. For the three sensors, the two dew-onset and dry-off times measured in both 2006 and 2007 crop seasons gave a leaf wetness duration (LWD) which was on average one hour less than visual observations. In order to establish a relationship between the surface wetness periods and wheat foliar diseases, LWD was compared with the Septoria leaf blotch (SLB) development risk (main winter wheat disease). A minimal surface wetness duration favourable to infection

for SLB was established.

Keywords: sensors, free moisture, measurement method, surface wetness, plant protection, agricultural warning system


Documents relatifs

The lowering of viscosity for an increasing water content (9) is understandable if processes at the grain boundaries are thought to be the main factor controlling creep,

Highly concentrated pollution plumes em- anating from the Mexico City urban agglomeration revealed that mixing ratios of Hg ◦ as large as 500 ppqv were related to combustion

We illustrate the idea with some results of our simultaneous observations of diverse classes of objects by the Ukrainian low-frequency radio telescopes (see Section 2) and the NDA

If we admit, as many do, that employment is inseparable from the conditions of its exercise (in terms of the intensity and interest of work, the degree of autonomy, and

Cancer clinicians displayed lower levels of emotional exhaustion and depersonalisation when com- pared to general practitioners, after adjustment for differ- ences in workload

To compare the ability of simulating N2O flux between models, we applied the outputs of DNDC such as soil temperature, water-filled pore space (WFPS) and inorganic nitrogen (NH4+ and

The United Kingdom Cereal Pathogen Virulence Survey (UKCPVS) is funded by HGCA and Fera. If you wish to attend please contact Emily Bennett at HGCA by

Hence, the aim of this 3-year study was to evaluate the performance of wheat under temporary and permanent intercropping with three different legume species and includ- ing pure