The purpose of seed health testing is to assure the safe movement of seed of different crops, for research or trade. It is premised on the hypothesis that many harmful organisms are carried by and moved together with the seed, and that these organisms have the potential to cause severe damage to crop production and crop seed for international trade once they are introduced. Seed health testing information reveals the organisms carried by the seed and the level of infection, or infestation, that will be introduced to another region or country. The information, although useful, does not indicate the importance of organisms carried by the seed. For most plant diseases, this information is not available. Such information comes from experiments or surveys under field conditions where the seed is grown.