Factors affecting eastern black nightshade (Solanum ptycanthum) seed germination

Abstract

Effects of environmental factors, especially light, on eastern black nightshade seed germination were studied under growth chamber conditions. Germination occurred only when temperatures were 20 C or higher for 12 to 24 h d−1. Optimum germination occurred within the constant temperature range of 28 to 33 C or with alternating temperatures of 30/25 and 35/30 C. In the dark, eastern black nightshade germination was poor except at high alternating temperatures of 30/25 and 35/30 C. Seed germination was enhanced by light when temperatures were suboptimal. Imbibition was a prerequisite for response of eastern black nightshade seed to light. The light requirement for eastern black nightshade germination was partially overcome by cold stratification, gibberellic acid (GA3), and high or alternating temperatures. Germination of eastern black nightshade seed was promoted by short exposure to sunlight but was inhibited by prolonged exposure, especially when irradiance was high.