Effect of Photoperiod, Propagative Material, and Production Period on Greenhouse-grown Ginger and Turmeric Plants

Abstract

The objectives were to 1) compare growth and yield of different ginger (Zingiber officinale) and turmeric (Curcuma longa) propagules grown under two photoperiods (Expt. 1); and 2) evaluate whether their growing season could be extended with night interruption lighting (NI) during the winter (Expt. 2). In Expt. 1, propagules included 1) micropropagated tissue culture (TC) transplants, 2) second-generation rhizomes harvested from TC transplants (2GR), and 3) seed rhizomes (R). Plants received natural short days (SDs) or NI providing a total photon flux density (TPFD) of 1.3 µmol·m−2·s−1. Providing NI increased number of new tillers or leaves per plant, rhizome yield (i.e., rhizome fresh weight), and dry mass partitioning to rhizomes in both species. There was no clear trend on SPAD index in response to photoperiod or propagative material. Although TC-derived plants produced more tillers or leaves per plant, 2GR ginger and R turmeric produced a higher rhizome yield. In Expt. 2, seed rhizomes of ginger and turmeric were grown under five treatments with different photoperiods and/or production periods: 1) 20 weeks with NI (20NI), 2) 24 weeks with NI (24NI), 3) 28 weeks with NI (28NI), 4) 14 weeks with NI + 10 weeks under natural SDs (24NISD), and 5) 14 weeks with NI + 14 weeks under natural SDs (28NISD). NI provided a TPFD of 4.5 µmol·m−2·s−1. Lengthening the production period and providing NI increased rhizome yield and crude fiber content in both species. SPAD index decreased when plants were exposed to natural SDs at the end of the production period (NISD treatments). Results demonstrate the potential to overcome winter dormancy of ginger and turmeric plants with NI, enabling higher rhizome yield under natural SDs.

High-tunnel Organic Ginger: Response to Propagation Material, Fertilizer, and Prepropagation Rhizome Storage

“…However, with regard to the planting material, we expected the vigorously growing MS plants with the tallest shoots and the greatest tiller numbers to have a greater SPAD index than the SS seeds. Others (Flores et al 2021) have reported no clear trend in SPAD index when growing ginger from seed rhizomes and transplants.…”

“…There were no significant year interactions for yield, but year was significant and plant materials were grown in the high tunnel over a longer period in 2020 than 2019 because of to earlier planting; therefore, data were analyzed by year (Table 7). The greater rhizome yield was anticipated because ginger is known to increase in yield with a longer growth time (Flores et al 2021, Yadav et al 2013. In terms of economic feasibility, the BCR and PI revealed MSs to be preferable to SSs and rhizome seed, Nature Safe fertilizer to be better than Phytamin, and pan storage was a better performer than flat storage (Table 7).…”

“…Ginger can be grown from rhizome pieces (called seeds), from seedlings from mature rhizomes, or from micropropagated seedlings from buds, with the latter type of propagule known to produce disease-free material (Bhagyalakshmi and Singh 1988;Flores et al 2021;Marsh et al 2021;Rafie et al 2012;Smith and Hamill 1996). According to Smith and Hamill (1996), micropropagated plants had a significantly reduced rhizome yield when compared with seed-derived plants.…”

Genotypic and Environmental Influence on Fresh Rhizome Yield of Turmeric (Curcuma longa L.)

“…For example, imports into the United States have increased over 5-fold between 2012 and 2021, from 11.53 million to 62.74 million [5] Although India has been and remains the largest producer and exporter of turmeric, there has been a push to expand turmeric production well beyond South and Southeast Asia. In the southern continental U.S., it has been shown that genotypic and environmental factors can interact to affect yield [6][7][8]. Agroecological approaches to turmeric production in these areas is especially important given that turmeric is a tropical crop and would need to be intensely managed to mitigate both supra-and sub-optimal temperatures and daylengths its normal range of production [9].…”

“…Despite the promising experimental success of shading, daylength modification and other environmental manipulation for the improved production of turmeric [6][7][8][9], the component of the agroecosystem that producers have perhaps the most control over is the selection of genotype. Of course, this assumes that a diverse pool of germplasm is available.…”