Seed Testing and Quality-Assurance
H igh-quality seed is the basis for profitable and productive agriculture, be it a large commercial field operation, a small familyowned farm, or a greenhouse-based operation producing bedding plants or specialty horticultural crops. Assessing seed quality and assuring the buyer of the validity of the seed label (Fig. 1) has been an important mission of the various seed regulatory agencies of state and federal governments and service-testing provided by commercial seed-testing laboratories around the world. Based on validity of labeling, commercial sales of seed have been a profitable business to both the seed producer and the consumer. In the United States and Canada, seed-testing rules have been developed and standardized by the Assn. of Official Seed Analysts (AOSA) and in other countries around the world by the Inter-
Ancient, Mid-Time, and Recent History of Seed Pathology
Seed is the basic unit of crop production. An optimum plant count depends on seed for their next progeny. Issues related to seed should be handled very carefully, since sowing of a poor-quality seed leads to undesirable loss in plant stand and hence crop yield. Focus on seed quality and seed health has been a point of serious consideration since time immemorial. Seed-related aspects are puzzling the researchers since long back. Well-developed science of seed pathology has been in existence for more than 100 years. Seed pathology includes studies on the mechanism of seed transmission, pathogenesis, epidemiology of seed-borne diseases, and control measures adopted against these diseases, ranging from crop management through chemical control to legislative precautions, as well as the technology of microbiological seed testing by covering the total range of seed-borne pathogens, viz., fungi, bacteria, viruses, nematodes, and physiological defects which may affect any member of the plant kingdom. The various aspects, viz., seed health, management of seed-borne diseases, seed treatments, and their detection and diagnosis techniques, were developed with the time. The systematic application of these techniques leads to the significant availability of healthy and disease-free quality seed. The institutional and technological developments in the science of seed pathology are being discussed in the present chapter.
Physiological Predetermination: Imbibition, Respiration, and Growth of Lima Bean Seeds
Temperatures 15�C or lower during the first hour of imbibition immediately inhibited respiration in lima beans, with proportional inhibition of subsequent growth of seedlings. Correlations between initial respiration rates and growth rates of seedlings were found in diferent lots of seeds.