Phakopsora pachyrhizi, the fungal pathogen that causes Asian soybean rust, has the potential to cause significant losses in soybean yield in many production regions of the U.S. To assist the development of new modes of soybean resistance to fungal infection, peptides were identified from combinatorial phage-display peptide libraries which inhibit germ tube growth from urediniospores of P. pachyrhizi. Two peptides, Sp2 and Sp39, were identified that inhibit germ tube development when displayed as fusions with the coat protein of M13 phage or as fusions with maize cytokinin oxidase/dehydrogenase (ZmCKX1). These peptides may be used in vitro to help control fungal infection. These peptides may also be expressed as transgenes in a plant to help the resulting transgenic plant defend against the fungi.