Tissue-cultured Creeping Bluestem for Restoration of Phosphate-mined Lands

Abstract

Tissue-cultured creeping bluestem (Schizachyrium scoparium var. stoloniferum (Nash) J. Wipff [Poaceae]), grown in pots containing sand tailings or overburden from a Florida phosphate mine, had shoot (4.6 g/plant [0.16 oz]), root and rhizome mass (5.2 g/plant [0.18 oz]), and vegetative tiller density (4.2 g /plant [0.15 oz]) similar to that obtained from plants started from rhizomes. Seeds of creeping bluestem germinated on mine soil but failed to grow. In the field, tissue-cultured bluestem survival averaged 88% over January, July, and October planting dates on sand tailings compared with 67% on overburden. One year after October planting, total tiller density and aboveground plant dry mass was 63.5 and 117 g/plant (2.24 and 4.13 oz), respectively, on sand tailings compared with 50 and 107 g/plant (1.76 and 3.77 oz), respectively, on overburden. Except in the October planting, soil did not affect bluestem plant diameter (mean 24.2 cm [9.5 in]). Because creeping bluestem produces few seeds, tissue culture can provide plants that establish and grow well on land after phosphate mining. Weed control will be essential to success.