Native Species

Abstract

lanting seeds with high levels of viability, physical purity, and freedom from noxious weed seeds increases the probability of successful establishment. Seed quality of native species, especially wild collections, can be uncertain on account of environmental conditions during seed development and maturation. Even when native seeds are produced under controlled-management practices, they may still have potential quality issues such as physical purity, viability, dormancy, and vigor. Factors that may affect native seed quality are stage of maturation at harvest (Figure 1) and methods of harvesting, drying, cleaning, and storage (Elias and Copeland 1994). Seed testing can assess the effect of such factors on quality and determine the true value of the seeds for planting. Seed testing is necessary for labeling and certification that require determination of the percentage of pure seeds, weed or other crop seeds, and inert matTesting native seed quality before planting cannot be overemphasized. Planting high quality seeds is the cornerstone for successful field emergence. The increasing use of seed certification for native species further emphasizes the need for accurate seed testing. Our objective in this article is to provide a summary of principles and procedures for some useful seed quality tests for natives and other species. Testing for physical purity and viability of seeds are the two most important tests needed to avoid weed problems and poor stand establishment. Other seed quality tests such as vigor tests, x-ray, and seed moisture content provide useful information about the quality of the seeds.