Forage seed quality: Dormancy, standards and quarantine

Abstract

There are many dimensions to the concept of seed quality. Viable seed which will not germinate when provided with all the requirements for germination is dormant. Forage grasses mostly exhibit non-deep physiological dormancy (PD), while physical dormancy (PY) is common in forage legumes where imbibition is prevented by the seed coat’s impermeability to water (hard seed). Methods for breaking PD and PY to allow germination testing and/or crop establishment are discussed.

In the seed industry seed quality standards are an important feature of quality assurance and may apply for seed production contracts, seed certification, seed sale and seed importing. Standards for these uses are discussed, with a comment on legislated minimum germination standards which may do little to offer protection to the buyer. Exported seed lots must meet the seed quality standards and phytosanitory/biosecurity requirements of the importing country, but while there is an obvious need to protect against the spread of economically important pests, they should not be used as unnecessary barriers to the seed trade.