The present invention relates to the field of plant breeding and disease resistance. More specifically, the invention includes a method for breeding corn plants containing quantitative trait loci that are associated with diplodia ear rot (DER), a fungal disease associated with Stenocarpella spp. The invention further includes germplasm and the use of germplasm containing quantitative trait loci (QTL) conferring resistance for introgression into elite germplasm in a breeding program for resistance to DER.