Carbohydrates and Agronomic Characteristics of Miscanthus × Giganteus As Affected By Cold Storage, Rhizome Size and Plot Age.

Miscanthus × gigantaeus (M. × giganteus), a sterile triploid hybrid of Miscanthus sinensis and Miscanthus sacchariflorus, has been extensively evaluated as a dedicated cellulosic energy crop in the North United States and Europe, with very favorable results, such as high yield with low fertilizer and pesticide inputs. However, little information is available for growing M. × giganteus as a cellulosic energy crop in the Southeast United States, where has a long growing season with reasonable rainfall that is ideal for cellulosic feedstocks production. This study was conducted in Georgia to answer the following questions. First, when is the best time to dig rhizome for transplanting to new fields? Or, how long can the rhizomes survive the optimal storage temperature? Second, what is the optimal rhizome size for successful M. × gigantaeus establishment in the Southeast? Third, what are the effects of rhizome age and mother-plot age on successful rhizome-propagation? Forth, is there relationship between rhizome carbohydrate and tiller emergence and growth? Results indicated that: 1) shoot emergence rate was maximized when rhizomes were stored under cold condition for about 2 months; 2) rhizome length of 10 cm would be considered long enough to ensure an acceptable emergence rate of 85-94%; 3) mother-plot age did not affect shoot mergence rate of all rhizome length levels except for 5-cm-long rhizomes, for which digging from older plots tended to have lower emergence rate;4) emergence rate for 5-cm-long rhizomes dug from 1-yr-old mother plots was negatively related to the carbohydrate contents, while positively related for the 5-cm-long rhizomes dug from a 3-yr-old mother plot.