Dormancy, Germination, and Emergence Characteristics of Fall Panicum (<i>Panicum dichotomiflorum</i>) Seed

Abstract

Fall panicum ( Panicum dichotomiflorum Michx.) seed were found to be dormant at harvest. This dormancy was overcome by an after-ripening period of 17 to 22 weeks, alternating germination temperatures (10 C for 16 h and 30 C for 8 h), stratification, and mechanical or chemical scarification. Soaking seed in gibberellic acid (GA 3 ) or thiourea for 1 day, or washing seed in running tap water for up to 96 h before seed were placed in a germinator, had no effect on dormancy. In the greenhouse, fall panicum emergence was greatest (82%) when seed were placed on the growth media surface. The maximum number of seedlings (39%) emerged in the field when seed were placed 1.3 cm below the soil surface, although some emerged from as deep as 5.1 cm.