Spatial Phase Synchronisation of Pistachio Alternate Bearing

Collective dynamics of chaotic oscillators has attracted much attention in many fields even including agriculture and forestry. Alternate bearing of tree crops is a phenomenon in which a year of heavy yield is followed by a light yield. This phenomenon has been modelled using a tent map known as a resource budget model (RBM). We applied in-phase/out-of-pahse analysis to yield data of a 9,562 pistachio plants population and revealed phase transitions and mode locking in the orchard. Using a developed network model consisting of diffusively coupled chaotic oscillators (RBMs) on which common noise imposed, we theoretically confirm the phase transitions mode locking and 1/3 power-law scaling in the yield data. Here, we demonstrate how three essential factors, i.e. common noise, direct coupling, and cropping coefficient gradient, explain the spatial synchrony of the orchard.