What does purity refer to in the context of seed?

Purity, when discussed in the context of seeds, refers specifically to the percentage of pure seed in a lot. This measurement determines how much of the total seed lot is composed of the targeted species or variety of seed. High purity is essential for ensuring that the seeds will grow into the desired crop, as it directly affects the performance and characteristics of the plants that will germinate from those seeds. In regulatory practices, purity tests help ensure that seed lots meet quality standards and are free from unwanted seeds or substances that could affect growth or yield.

Understanding seed purity is crucial for growers and agricultural professionals, as it impacts everything from planting decisions to marketability. The other choices pertain to different aspects of seed quality, such as viability or treatment, but they do not encapsulate the definition of purity itself, which is clearly focused on the composition of the seed lot with respect to the specific seed type intended for planting.