Effects of temperature, water potential, and sodium chloride on Indiangrass germination

Abstract

Indiangrass [Sorghastrum nutans (L.) Nash] is widely used in range seeding. Objectives of this study were to determine the effects of temperature, water potential, and sodium chloride on germination of 'Lometa', 'Cheyenne', 'Llano', 'Oto', and 'Tejas' Indiangrass. Seeds were germinated at 6 alternating temperatures ranging from 5-15 to 30-40 degrees C (12 hours-12 hours). Lometa, Cheyenne, and Tejas seeds were germinated in polyethylene glycol (mol. wt. = 8,000) solutions mixed to approximate water potentials of 0, -0.4, -0.8, -1.2, and -1.6 MPa and in 0, 0.06, 0.12, 0.18, and 0.24 mol liter-1 sodium chloride solutions. Optimum temperatures for percent germination were 10-20 to 25-35, 10-20 to 20-30, and 15-25 and 20-30 degrees C for Cheyenne and Tejas, Llano and Oto, and Lometa seeds, respectively. Percent germination of Cheyenne and Lometa seeds was reduced at water potentials of -0.8 MPa and lower, while Tejas seeds exhibited lower percent germination than controls at -1.2 and -1.8 MPa. Percent germination of Cheyenne and Lometa seeds was reduced by sodium chloride concentrations of 0.12 mol liter-1 and greater. Germination of Tejas seeds was reduced at 0.18 and 0.24 mol liter-1. Indiangrass varieties appear to germinate within a similar range of temperatures but vary in germination response to low water potentials.