Submitted to: American Society of Horticulture Science Meeting
Publication Type: Abstract Only
Publication Acceptance Date: June 25, 2003
Publication Date: October 5, 2003
Citation: Krizek, D.T., Clark, H.D., Davis, K.M., Camp, M.J., Ritchie, J.C. 2003. Comparative germination of 1998, 2000, and 2002 lots of eastern gamagrass seed in the greenhouse [abstract]. HortScience. 38(5):781. Technical Abstract: A major obstacle to successful establishment of eastern gamagrass [Tripsacum dactyloides (L.) L.] is its erratic germination because of severe seed dormancy. Our previous studies indicated that 1998 and 1999 lots given a proprietary seed priming treatment (Germtec II TM) showed a decline in germination in peat-lite mix in the greenhouse over a six month period (March to Sept. 1999). The study was repeated in March and Sept. 2002, using 1998, 2000, and 2002 seed lots. There was no appreciable difference in germination percentage between the two 2002 tests, but storage time had an effect on time and rate of germination as seen in previous studies. Germination of the 1998 and 2002 lots at 28 days was comparable, viz., 42 and 40%, respectively, while that of the 2000 lot was 30%. The shape of the germination curves was similar for all three lots but the actual percentage germination values were much lower for the 2000 seed lot at all dates, providing further evidence that this lot may have developed physiological and/or morphological barriers to germination during maturation. Further studies are needed to identify the precise nature of these barriers and to develop improved methods for breaking dormancy. The low germination rate for all seed lots may be partially explained by the high fraction of dormant seed, based on initial tetrazolium chloride tests run prior to shipment.