This document discusses using a remote sensing-based handheld NDVI sensor to quantify stripe rust reaction in wheat. NDVI values decrease as stripe rust infection increases due to breakdown of foliar pigments and decreased physiological activity. A field experiment was conducted on 120 wheat genotypes under stripe rust pressure. NDVI readings were recorded and correlated with disease severity measurements (AUDPC values). A strong negative correlation was found between NDVI and AUDPC, though the correlation improved after accounting for the effects of co-occurring spot blotch disease. Plant height was also found to correlate with susceptibility, with taller wheat types being more susceptible.