The present work explores the application of microwave remote sensing to distinguish between healthy and infested date palm trees, using a novel approach centered around the scattering to absorption width ratio (SAWR). Through comprehensive analytical formulations and numerical modeling, we investigate the interaction of palm trees with microwaves at oblique incidence, specifically at a frequency of 2.45 GHz (ISM-band). The study examines the behavior of TE and TM polarizations waves (relative to the -axis), providing detailed analyses of their scattering and absorption characteristics as functions of incident angles. Our findings demonstrate that the SAWR metric is a promising indicator for assessing palm tree health, effectively differentiating between healthy and pest-infested trees. This research offers a non-destructive, real-time method for monitoring tree health, with significant implications for pest detection in agricultural practices.