Abstract
Ornamental gingers are popular cut flowers and have been promoted as a promising potted flower crop because of unique foliage, long-lasting colorful bracts, and few pest problems. Rhizomes are the primary means of propagation in late spring followed by shoot growth and flowering, and plants enter dormancy under short days in the fall. Termination of dormancy is important for greenhouse forcing and extending the growing season. Rhizomes of five ginger species (Curcuma alismatifolia Gagnep., C. cordata L., C. roscoeana Wallich, Globba winittii C.H. Wright, and Kaempferia galanga L.) were either: 1) stored for 0 to 16 weeks at 15, 20 or 25 C; or, 2) stored for 0 to 2 weeks at 10 or 15 ºC followed by 0 to 2 weeks at 25, 30, or 35 ºC; or, 3) treated with 0 to 300 ppm ethephon or BA and then stored for 0 to 3 weeks to determine the effect on growth, development, respiration rates, and carbohydrate content. Upon completion of treatment application, rhizomes were planted in a peat moss:bark:perlite mix and placed in a greenhouse with 25 ºC day/21 ºC night temperatures with 40% shade. DTE and DTF for Globba were hastened when rhizomes were stored for 16 weeks at 25 ºC or 3 weeks at 15 ºC followed by 3 weeks at 30 ºC. For C. alismatifolia, DTE and DTF were hastened when rhizomes were stored for 3 weeks at 10 ºC followed by 3 weeks at 30 ºC. For C. cordata, DTE and DTF were hastened with rhizome storage of 2 weeks at 10 ºC followed by 3 weeks at 35 ºC. For C. roscoeana a 3 or 4 month storage treatment was found to hasten emergence. Results indicated that Kaempferia should be stored at 25ºC for 16 weeks to enhance emergence and flowering. Neither application of ethephon nor BA significantly affected growth or flowering of any in the ginger species after storage. The response of respiration and carbohydrate concentration was not consistent with rhizome and plant growth responses.
|
