Leaf wetness spatial variability within grapevine canopy

Leaf wetness duration (LWD) is key agrometeorological variable and strongly influences disease development. Knowledge about its spatial variability within a grapevine (Vitis vinifera) canopy may be significant in improving protection management. LWD was evaluated in different grapevine canopy layers through visual inspections conducted for 10 nights and a set of sensors installed for LWD monitoring during the growing season. Eight thermocouples were installed inside the canopy to measure leaf and air temperature, and an agrometeorological station was set up near the experimental field for data collection. The goal of this study was to assess LWD spatial variability within a cordon-trained grapevine canopy and its possible relationship with a temperature microclimate. Results showed that LWD varies in a cordon-trained grapevine depending on canopy layer. Leaf temperature varies in the same manner, thus demonstrating its strong influence on LWD.