Early growth, essential oil and zerumbone concentration of Zingiber zerumbet (L.) Smith as affected by different types of organic fertilizers and harvesting times

Abstract

Zingiber zerumbet is a perennial tuberous herbal plant that has been traditionally used for medical and culinary flavor for centuries. Recently, the zerumbone compound in Zingiber oil has been intensively studied in the pharmacological field. The Malaysian government has encouraged local entrepreneurs to explore and commercialise herbal-based products derived from native herbal plants, including Zingiber zerumbet. Large-scale cultivation is required to provide a continuous supply of herbal plant derivatives for industrial purposes. However, little is known about Zingiber zerumbet cultivation. As herbal plants are utilized for health and nutrition, they must be cultivated employing good agricultural practices to assure purity, quality, and maximum quantity of bioactive compounds. Accurate harvesting time is also critical, as it impacts the amount of essential oil and its constituents. As a result, the purpose of this research was to investigate the effects of various types of organic fertilizers and harvesting times on the early stage of growth, essential oil, and zerumbone concentrations of Zingiber zerumbet (L.) Smith. Bat guano, goat manure, and quail litter were the organic fertilizers researched. The nine treatments were arranged in a split-plot design with five replications. The morphological growth parameters were regularly measured every two weeks. The plants were harvested for destructive data at 90, 120 and 150 DAT. The essential oil was extracted from Zingiber zerumbet rhizomes by means of Supercritical-Fluid-Extraction (SFE) and analysed by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography coupled with Flame Ionization Detection (GC-FID). Data were analysed by using SAS version 9.4 package. The mean values of the growth parameters and yield components of Zingiber zerumbet (L.) Smith were compared between treatments. The Duncan new multiple range test (α =0.05) was used for mean comparison. Based on this study, there were significant effect of different types of organic fertilizers and harvesting times on early growth parameter, essential oil and zerumbone concentration of Zingiber zerumbet (L.) Smith. Quail litter (F3) was significantly produced the plants with the maximum height, number of leaves and tillers and produced the highest fresh and dry weight of root and rhizome. Besides, T3 (150 DAT) gave the highest mean value for all parameters measured. Quail litter produced the highest percentage of essential oil, while plants treated with quail litter and goat manure had the highest percentage of zerumbone. Therefore, a combination of quail litter and 150 DAT was recommended in the cultivation of Zingiber zerumbet plants.