The application of fertilizer and the mycorrhizal fungus, Pisolithus tinctorius, did not increase the height growth of loblolly pine seedlings during their first 4 yr of growth. Fertilization, however, did increase the overall number of fusiform rust galls per infected tree. This increase was highly significant on the susceptible control seedlings, but was not significant on resistant Livingston Parish seedlings. Apparently, cultural practices such as fertilization can be applied to rust-resistant seedlings, such as the Livingston Parish seed source, without significantly increasing rust severity. [Fusiform rust is caused by Cronartium quercuum (Beck.) Miyabe ex Shirai f. sp. fusiforme.].