[en] Leaf wetness duration (LWD) is an important factor influencing the occurrence of plant disease
<br />epidemiology. Despite considerable efforts to determine LWD, little attention has been given to
<br />study its variability within the canopy. The objective of this study was to evaluate its
<br />spatiotemporal variability in wheat fields in a heterogeneous landscape. The spatiotemporal
<br />variability of LWD was evaluated in a site close to Arlon (Belgium) during the period May to July
<br />2006 and 2007. LWD measurements were made using a set of flat plate sensors deployed at
<br />five different distances from a 18 m high hedge (5, 10, 20, 50, 100 m). Each set of two
<br />sensors was placed horizontally close the flag leaf. In addition, we collected the amount of
<br />dew water that deposited on rigid epoxy plates placed next to each sensors. Experimental
<br />results showed that LWD measurements revealed substantial heterogeneity among sensor
<br />positions. LWD is longer for sensors closer to the hedge mainly because of its shadowing
<br />effect. 3 to 4 hours of difference was observed between sensors located at 5 m and those
<br />located at 100 m, and besides, a significant quantitative difference (p < 0.0001) of dew
<br />deposit was observed between area beside hedge and those placed at 100 m. In summary, this
<br />study provides new information on how wetness is distributed on wheat leaves according to
<br />the distance from a hedge. This leads to local microclimate conditions that will contribute to
<br />the disease spatial heterogeneity.
El Jarroudi, Moussa ; Université de Liège - ULiège > Département des sciences et gestion de l'environnement > Département des sciences et gestion de l'environnement
Giraud, F.
Delfosse, Philippe
Huber, Laurent
Hoffmann, Lucien
Tychon, Bernard ; Université de Liège - ULiège > Département des sciences et gestion de l'environnement > Département des sciences et gestion de l'environnement
Language :
English
Title :
Spatial heterogeneity of leaf wetness duration in winter wheat canopy and its influence on plant disease epidemiology
Publication date :
07 July 2010
Journal title :
Phytopathology
ISSN :
0031-949X
eISSN :
1943-7684
Publisher :
American Phytopathological Society, Charlotte, United States