Assessment of Adequate Volumetric Water Content for Managing Farfugium japonicum (L.) Kitam. in the Indoor Gardens

Abstract

Background and objective: The present research study aimed to investigate the optimum substrate volumetric water content (VWC) needed for <i>Farfugium japonicum</i> (L.) Kitam. to maintain its performance in the indoor garden.Methods: The threshold levels of substrate VWC were evaluated as 0.1, 0.2, 0.3 or 0.4 m<sup>3</sup>⋅m<sup>-3</sup> using an automated irrigation system with capacitance soil moisture sensors and datalogger. Plant growth and physiological responses were measured and analyzed at 10 weeks after treatment. Plant growth was investigated by measuring survival rate, plant height, leaf length, leaf width, leaf number, root length, fresh and dry weight of shoot and root. Physiological responses were observed by analyzing antioxidant enzymes (SOD, POD) and antioxidants (MDA, proline), maximum quantum yield (Fv/Fm) and total chlorophyll contents.Results: The results of drought tolerance measurement by the treatment group showed that the overall growth was the highest in the 0.3 and 0.4 m<sup>3</sup>⋅m<sup>-3</sup> treatment plot and the lowest in the 0.1 m<sup>3</sup>⋅m<sup>-3</sup> treatment plot. Under the droughtstressed condition of the 0.2 m<sup>3</sup>⋅m<sup>-3</sup> treatment, growth was not as efficient as the 0.3 and 0.4 m<sup>3</sup>⋅m<sup>-3</sup> treatments due to the relatively higher moisture content, but there was no statistical difference between the 0.3 and 0.4 m<sup>3</sup>⋅m<sup>-3</sup> treatments in the maximum quantum yield (Fv/Fm) and also total chlorophyll content. Furthermore, for antioxidant activities, SOD, POD, and MDA showed high values, but no statistical differences were found among treatments except for the 0.1 m<sup>3</sup>⋅m<sup>-3</sup> treatment, which was under severe drought stress in terms of proline.Conclusion: Overall, the results indicate that <i>Farfugium japonicum</i> (L.) Kitam., has a tolerance to drought, and for managing indoor gardens the adequate soil moisture content for the growth is at least 0.2 m<sup>3</sup>⋅m<sup>-3</sup> assuming the use of identical substrate in this experiment.