Preliminary Analysis of Trunk Electrical Bio-Impedance in Professional Apple Orchards

Accurate, low-power and reliable plant monitoring systems in smart agriculture are crucial to better resource management, such as water usage. Direct plant monitoring, particularly trunk electrical bio-impedance monitoring, is a promising solution to precisely monitor plants' health conditions without relying only on environmental measurements. This paper showcases data acquisition and a preliminary observation campaign on apple trees from a professional orchard using a previously developed trunk bio-impedance sensor. The system operated in the field for one year, continuously sampling data every 10 minutes. The implanted electrodes exhibited good biocompatibility after an initial wound recovery period from the plants. The preliminary results revealed trunk bio-impedance trends generally consistent with existing literature regarding vegetative states and astronomical seasonal variations in apple trees; moreover, the strength of daily components ranged from high values of seasonality intensity index (4.94, 6.37) during spring (vegetative growth) to low values during summer (0.29, 0.41), likely due to high temperatures and limited water availability.