Optimum Nutrient Level on Growth, Flowering, and Rhizome Production in Curcuma

ABSTRACT

This study investigated the effect of liquid fertilizer treatments on growth, flowering, leaf mineral content, and rhizome production during forcing of Curcuma alismatifolia ‘Chiang Mai Pink’ and C. thorelii ‘Chiang Mai Snow’. Plants were irrigated with 200 mL of 1.3 g L⁻¹ of 15 nitrogen (N) -7 phosphorus (P) -14 potassium (K) water soluble fertilizer at 0, 1.3, 2.7, 4.0, 5.3, or 6.6 g L⁻¹ weekly. Days to flower, flower stem length, and leaf length were recorded, the mineral contents in leaves were analyzed, and the number of rhizomes with tuberous roots were recorded at harvest. Flowering of the first inflorescence in both C. alismatifolia ‘Chiang Mai Pink’ and C. thorelii ‘Chiang Mai Snow’ was significantly delayed when plants received 6.6 g L⁻¹ fertilizer as compared to the control plants. The number of rhizomes with more than 4 tuberous roots was highest when plants received 2.7 g L⁻¹ fertilizer. No medium-sized rhizomes with more than seven tuberous roots were produced when ‘Chiang Mai Pink’ plants received 0, 4.0, 5.3, and 6.6 g L⁻¹ fertilizer. Based on the production of rhizomes with four to six tuberous roots, optimum concentration of 15N -7P -14K water soluble fertilizer is 2.7 g L⁻¹ for C. alismatifolia ‘Chiang Mai Pink’ and 1.3 to 4.0 g L⁻¹ for C. thorelii ‘Chiang Mai Snow’. Although high boron content occurred only in the outer part of the second leaf when fertilizer concentrations were increased, leaf-margin burn (LMB) symptoms were not observed in both species and this could not be related to the production of rhizomes.

Keywords:

• nutrition
• tuberous roots
• foliar analysis
• optimum nutrition requirement
• leaf-margin burn

ACKNOWLEDGMENT

Financial Support for this study was provided by the Agricultural R&D Promotion Center, Ministry of Agriculture and Forestry, Korea.

Notes

^aThe order of flowering: first, second and third inflorescence.

^bDTF: Days to flower from the date of potting, FSL: scape and inflorescence length, LL: leaf length, and NO: no. of plants flowered. Thirteen C. alismatifolia ‘Chiang Mai Pink’ rhizome and 15 C. thorelii ‘Chiang Mai Snow’ rhizome were used in each treatment.

^cThe number of total inflorescence included those that did not develop fully showing any bracts.

^d—, ns, *, **, data not analyzed, non-significant, significant at 5% and at 1% level.

^aMean of two replications. Leaf samples were from inner part/outer part of the distal part of the leaves. If no significance was observed between the readings of inner part and outer part, mean values were presented.

^bInner part/outer part of the leaf.

^c—, ns, *, **; data not analyzed, non-significant, significant at 5% and at 1% level.