Recent studies have brought into question the mechanisms through which weeds cause reduced crop yield. In modern agricultural systems, it is rare that nutrients, light, or even water are limiting- yet weed presence still causes significant yield loss. Thus, understanding how weeds are sensed by crop plants and the physiological and developmental processes that are negatively affected by weed presence could provide new insights needed to develop novel weed resistance in crops. In order to gain an enhanced understanding of crop- weed interactions, we have undertaken a transcriptomics approach to identify weed-responsive genes in soybean and corn under field conditions. Over multiple years, with multiple reps per treatment, young leaf material was collected in weed- free or weed infested plots from soybean at the V3 stage of growth,  and corn at the V4 stage of growth.  RNA was extracted from the leaf and subjected to RNAseq  or microarray/qRT-PCR analysis. Numerous weed-responsive genes were identified in this effort.   This poster will compare and contrast gene expression between the two crops, The results  provide an indication of the nonresource limited  processes  that alters their growth and development  responses.