Pine seeds are considered one of the major pathways of introduction of F. circinatum into new countries, as it occurred in Chile [8], South Africa [9], and Spain [10]. Pine seed is also one of the potential inoculum sources of F. circinatum in nurseries [2,11,12]. This fungus is a seed-borne pathogen in Pinus radiata [11]; it has also been detected in seeds of P. taeda [13] and P. elliottii [14]. Fusarium circinatum may infest seeds superficially in cones growing on healthy branches [11]. The fungus can also infect seeds internally, where it causes damage to embryo and gametophyte tissues [13]. The mechanisms by which F. circinatum infects seed are unknown, but three types of infection have been identified [11]: superficial, active internal and dormant internal, though the latter is not detectable on plate medium. The extent of internal and/or external seed contamination depends on the pine species and environmental conditions [2]. Fusarium circinatum was isolated from up to 83% of seeds of P. radiata [11]. Anderson et al. [15] determined that 34% of P. elliottii infested seed was internal