Tracking the pulse of olive trees: high-frequency data collection across root, trunk, branch, and fruit

Recently, several studies about tree and fruit growth management have emphasized the significance of continuous plant-based monitoring (tracking) as a useful tool in precision farming. During the growth of a plant, various physiological changes occur within its different organs. Consequently, continuous monitoring of these organs and analysing and comparing the collected data will play a key role in gaining insights into their dynamic trends and reciprocal relationships. In this study, continuous hourly measurements of the diameter of the root, trunk, branch, and fruit in the olive cultivar ‘Rosciola’ during the third phase of fruit growth (mesocarp cell expansion) were conducted using proximal plant-based sensors (dendrometer). The circadian measurement of diameters related to different organs were recorded to compare the dynamics of different organs and unveil comprehensive models. Examining the recorded trends, different correlations among different organs were found. During four weeks, a strong relationship was observed between trunk and branch (r2=0.79) and between fruit and root (r2=0.71), whereas the correlation between root and trunk was very weak (r2=0.11). In contrast, when dividing experimental period into two parts, the initial two weeks and latter two weeks, a strong relationship was found between root and trunk over the latter two weeks (r2=0.81), likely due to a decrease in evapotranspirative demand. These results can be valuable for the development of a more precise model for smart olive management.