Rate and Uniformity of Herbaceous Perennial Seed Germination and Emergence as Affected by Priming

Abstract

Seeds of tickseed (Coreopsis lanceolata L.) and purple coneflower [Echinacea purpurea (L.) Moench] were primed in aerated solutions of distilled water or 50 or 100 mM salt (potassium phosphate, pH 7.0) at 16C for 3, 6, 9, or 12 days. Coreopsis seeds primed in the 50 mM buffer germinated the most rapidly and uniformly, and, under stress conditions in the greenhouse, resulted in a faster-growing, more-uniform crop than other treatments. Seeds primed in distilled water and the 50 mM buffer germinated faster and at higher rates at suboptimal temperatures in the laboratory than nonprimed seeds. Priming of Echinacea purpurea seeds for 6 or 9 days in distilled water or in the 50 mM buffer resulted in faster, more-uniform germination than other treatments. Seedling emergence under stress conditions was improved by all priming regimes, with best emergence occurring in treatments that lasted > 3 days. Priming also increased germination rates of E. purpurea at suboptimal temperatures in the laboratory.