COMPARATIVE GROWTH OF ELEPHANT EAR TARO (ALOCASIA MACRORRHIZA) AND GIANT SWAMP TARO (CYRTOSPERMA MERKUSII) IN HAWAI‘I

Abstract

Alocasia macrorrhiza and Cyrtosperma merkusii are root crops in the family Araceae that have the potential as animal feed in Hawai‘i. This research focused on growing C. merkusii and two varieties (Laufola and Faitama) of A. macrorrhiza to evaluate its growth, yield, and nutrient composition. A randomized complete block design was used to set up two growth trials in 2018 and 2019. Varieties were grown in pots in the first trial and directly on the ground in the second trial. Plant growth was measured weekly by plant height and leaf area of the main plants. Yield was measured by weights of the leaf blades, petioles and stems at harvest. Lateral plants and their weights were also measured. The yield data at harvest were statistically analyzed with a one-way ANOVA in PROC GLM and means were separated using a Post-hoc test, Least Significant Difference, at 5%. The influence of plant height, leaf area, number of leaves produced by main plants, number of lateral plants, and their total weight on yield were analyzed by Pearson's Correlation Coefficient. Wet chemistry analysis was performed for basic and mineral composition of the leaf blades, petioles, and stems harvested from the second growth trial. Growth and yield of plants in the second trial were generally superior to those in the first trial in which the Laufola variety had the highest growth increase in height and leaf area. The Laufola variety had the greatest average yield, in stem (54,896 kg/ha), petiole (99,647 kg/ha), and leaf blades (25,563 kg/ha) in the second growth trial. Plant height, leaf area, and number of leaves produced by the main plants had a strong positive influence with the yields. In the nutrient analysis, the leaf blades of the Faitama and C. merkusii variety had the ratios of Crude Protein-Acid Detergent Fiber-Neutral Detergent Fiber-Non Fiber Carbohydrates-Total Digestible Nutrients (CP-ADF-NDF-NFC-TDN) that could meet requirements or supplement the feedstuff of animals such as those of lactating cows. Considerable concentrations of Ca, Mg, P, K, and Na of the macrominerals and Fe, Cu, Mn, Zn, and Mo of the microminerals were detected in yield samples. The leaf blades and petioles had the greatest concentrations of these minerals with comparatively lower values in stems. Laufola and Faitama varieties have a better potential to be grown in Hilo, Hawai‘i. Keywords: Alocasia macrorrhiza, Cyrtosperma merkusii, Growth, Nutrients and Yield