Seed vigor, vigor tests, and field performance of seed constitute a single multi-dimensional research area. Vigor is an important attribute of the physiological quality of seed only to the extent that it can be measured and has an influence on the field performance of seed. Research needs and general methodology in the vigor-field performance area are discussed from the perspective of Brazilian agriculture. Envigoration treatments for seed are a new area of research. Little progress has been made. Some aspects of research in this area are beyond the capabilities of seed companies and public seed research agencies and laboratories. Other aspects can and should be explored on a low priority basis by public seed researchers.