Preliminary trial to determine the performance of micropropagated turmeric (Curcuma longa L.) plants in Virginia, USA

Turmeric (Curcuma longa L.) is a high-value spice primarily cultivated in India and increasingly in demand in the United States. It is propagated vegetatively through rhizomes; however, this method has a low multiplication rate and is prone to high disease incidence. Disease control via fungicide application is often ineffective and environmentally unsustainable. Micropropagation is an ideal method for the mass production of disease-free plant material. However, there is evidence that the micropropagated plants have lower yields during the first growing season. This experiment tested the hypothesis that turmeric plants propagated conventionally (via rhizome cuttings) and through tissue culture produce comparable yield and quality under the subtropical climate of Virginia. Twenty-four of each propagation method (cultivar ‘Hawaiian Red’) were planted in a split-plot design at the research farm and irrigated using a sprinkler system. Chlorophyll concentration index (µmol m-2) was measured twice during the growing season using three fully expanded leaves from the south-facing canopy. At harvest, data were collected on plant height, shoot number, fresh and dry weight of shoots, rhizomes and roots, canopy diameter, rhizome total soluble solids (TSS), and titratable acidity (TA). The micropropagated turmeric plants had significantly lower rhizome yield but higher TSS and TA compared to conventionally propagated plants. Despite being smaller at planting, micropropagated turmeric plants reached comparable height, shoot number, and root weight, and showed no sign of disease or rhizome contamination at harvest.