Assessment of shade adaptation and spacing on growth and yield of wild turmeric (Curcuma aromatica Salisb.)

Abstract

Curcuma aromatica (common name: wild turmeric), well known for antibacterial, antifungal, and cosmetic properties, is a member of the genus Curcuma belonging to the family Zingiberaceae. A study was undertaken at the Department of Agronomy farm, College of Agriculture, Vellanikkara, Thrissur, Kerala from May to December 2021 to study the effect of shade and spacing on the growth, yield and, quality of Curcuma aromatica. The experiment was laid out in a two factorial completely randomized block design with three replications. Shade was taken as the first factor, and spacing was taken as the second factor. Two levels of the first factor (open and 25% shade) and three levels of the second factor (60 cm x 40 cm, 40 cm x 25 cm, and 25 cm x 25 cm) were evaluated. Plants grown under shaded conditions were taller (142.50 cm) and had more leaf area (453.42 cm2) than plants grown under open (92.17 cm and 377.36 cm2 respectively) conditions. Open conditions resulted in a greater number of leaves (10.41) and tillers (2.02) compared to shade (7.38 and 1.44 respectively). But yield and yield characters except number of fingers were not statistically different in both the treatments. The number of fingers was higher in open (36.26) condition and it was lower in shaded condition (30.31). Essential oil content was higher in shade (3.32%) compared to open (3.06%). Concerning the effect of spacing on growth and yield, 25 cm x 25 cm spacing (123.79 cm) had produced taller plants followed by 40 cm x 25 cm (118.93 cm) and 60 cm x 40 cm (109.30 cm) spacing. The treatment 60 cm x 40 cm significantly resulted in higher number of leaves, tillers and leaf area and lowest was produced by 25 cm x 25 cm. The yield and yield characters (rhizome length and number of rhizomes) were significantly higher under 60 cm x 40 cm spacing compared to other treatments. But per hectare yield was higher at 25 cm x 25 cm spacing since plant population is more in this treatment. The treatment combination 25 cm x 25 cm spacing with shade had produced maximum plant height and lowest was produced by 60 cm x 40 cm spacing under open conditions. Number of leaves, number of tillers, number of rhizomes were found to be higher at 60 cm x 40 cm under open conditions. There is no statistical difference between treatments for leaf area, rhizome yield of single plant, rhizome yield (kg ha-1) and essential oil content. The results acknowledge that Curcuma aromatica is a shade tolerant crop. It can be grown in either open or shaded areas. To achieve a higher yield, it is preferable to use a 25 cm x 25 cm spacing