Vegetative, Photosynthetic, and Anthocyanin Content of Turmeric (Curcuma longa L.) Applied with Organic Foliar Fertilizers

In the Philippines, turmeric is used as a preservative and as medicine. However, due to the limited knowledge of its fertilizer management, this has resulted in low growth and yield. Foliar fertilizers are now commonly used in organic farming. A study was done to evaluate the effect of different foliar fertilizers: seaweed, bamboo shoot, Japanese snail, and commercial liquid fertilizer, arranged in a randomized complete block design with three replications, based on vegetative, photosynthetic, and anthocyanin content using methanol extraction of turmeric. Photosynthetic parameters were measured using the Li-6800 Portable Photosynthesis System. Results demonstrated that fermented seaweed significantly enhanced vegetative growth, increasing plant height at 19.72 ± 2.00 SD cm (3rd week), 28.53 ± 1.68 SD cm (5th week), and 36.40 ± 1.31 SD cm (7th week), and leaf length by 2.57 cm relative to the control. In contrast, the application of fermented Japanese snail yielded the highest anthocyanin concentration at 5.18 ± 0.14 SE µg/g and markedly improved photosynthetic traits, including assimilation rate at 11.26 ± 0.31 mmol CO₂ m⁻² s⁻¹, stomatal conductance to CO₂ at 393.71 ± 7.41 SD mmol m⁻² s⁻¹ and total conductance at 42 ± 1.18 SD Pa. Notably, anthocyanin content exhibited a strong positive correlation with assimilation rate (R=0.99) stomatal conductance (R=0.84) and total conductance (R=0.84), and a negative correlation with plant height (R=0.61). Thus, the application of fermented seaweed can enhance morphological parameters, while the fermented Japanese snail foliar application resulted in better photosynthetic efficiency and anthocyanin content.