Innovative water status monitoring of white grape varieties with on-plant sensors

Abstract

Context and Purpose. Climate change presents significant challenges to agricultural sustainability, particularly through the increasing frequency of drought and water scarcity. Effective water management is essential for optimizing crop yields while minimizing resource consumption. This study investigates the efficacy of two innovative sensors for on-plant water measurement in two white grape varieties, comparing their readings to stem water potential (SWP) values. While previous research has demonstrated the effectiveness of these sensors in various woody species, literature specifically addressing their performance in white grape varieties remains limited.

Materials and Methods. During the 2024 growing season, we tested the leaf vapor condensation sensor FylloClip® and the stem water potential microtensiometer FloraPulse®. These sensors were installed on two white grape varieties, Sauvignon Blanc (Vitis vinifera L.) and Chardonnay (Vitis vinifera L.), in a research vineyard located in Kaltern (Bolzano, Northern Italy). Two sensors of each type were mounted on two plants of each variety, and eight SWP measurement sessions were conducted using a Scholander bomb during critical phases of water stress.

Results. The season began with above-average rainfall, resulting in robust leaf development and limited fine root formation. However, a significant increase in temperature, coupled with a lack of rainfall from July onwards, led to pronounced water stress by August. The correlation between the FloraPulse® sensor data and SWP measurements was strong (R2=0,968) and statistically significant, despite one outlier on August 20 due to cloudy conditions affecting SWP accuracy. Notably, the two grape varieties exhibited distinct responses to water stress, reflective of their differing isohydric and anisohydric behaviors, with Sauvignon Blanc and Chardonnay, respectively. Although the FylloClip sensor provided valuable specific information, its correlation with SWP values was less robust.

These findings indicate the considerable potential of microtensiometer technology to enhance irrigation practices, reduce water consumption, and mitigate physiological disorders, such as berry shrivel, in white grape varieties. This research highlights the importance of innovative monitoring tools in promoting sustainable viticultural practices in the face of climate change challenges.