Evaluation of Curcuma as potted plants and cut flowers

Abstract

Sixteen accessions of Curcuma germplasm that included C. alismatifolia 'Chiang Mai Pink', and 'Lady Di' and C. thorelii 'Chiang Mai Snow' and C. alismatifolia 'Pink', C. parviflora 'White Angel', and C. sp. 'CMU Pride' were evaluated for use as potted plants or as cut flowers. All cultivars of C. alismatifolia and C. thorelii 'Chiang Mai Snow' were considered suitable for cut-flower and pot-plant use, respectively. C. parviflora 'White Angel' also proved to be a suitable cultivar for potted plant production. Optimum storage temperatures for rhizomes in relation to greenhouse forcing and ethanol-soluble glucose, fructose and sucrose concentrations were determined. Storing rhizomes at 25° - 30°C for 2 - 3 months after harvest is recommended to break dormancy. Plants of C. parviflora 'White Angel' flowered 50 - 89 d after potting and can be used as potted plants. Plants of C. alismatifolia flowered 96 - 133 d after potting, with floral stem-lengths suitable as cut flowers. High levels of boron or manganese were correlated with burn symptoms at the margins of the leaves ['leaf-margin burn' ('LMB')] and were observed in old leaves of 'CMU Pride' at flowering. Levels of ethanol-soluble fructose, glucose and sucrose in the tuberous roots of Curcuma were higher than the levels in rhizomes, and increased as storage temperatures increased. Accelerated leaf emergence from rhizomes stored at 30°C took 16 d and was associated with increases in glucose and fructose contents. Very similar morphological characters between C. thorelii 'Chiang Mai Snow' and C. parviflora 'White Angel' emphasised that identification of Curcuma accessions using DNA-markers is required for future studies.