Effect of three different organic fertilizers on growth, yield, and essential oil content of basil (Ocimum basilicum var. pilosum)

Basil (Ocimum basilicum var. pilosum) is an herbaceous plant species exhibiting various economic and medicinal values. This study was conducted to determine the effect of three different organic fertilizers, namely cow manure, worm castings manure, and Komix organic fertilizer, on the growth, yield, and essential oil content of basil in Thu Duc City. The results showed that using worm castings manure (25 tons/ha) decreased the growth parameters including the average height of main stems and the average number of leaves and lateral branches, whereas increased significantly the plant height (41.8 cm), stem diameter (6.0 mm), number of primary branches (13.5 branches), number of leaves (16.8 leaves), chlorophyll index (41.3) and number of shoots after regeneration (20.2 shoots), compared to the control. Besides, using worm castings manure (25 tons/ha) also helped increase the average fresh weight of basil stems and leaves (93.3 g/plant), theoretical yield (24.9 tons/ha), actual yield (14.7 tons/ha), essential oil content (0.5 mL) /100 g), and yield of essential oil (1.1 L/ha). The study also confirmed that using worm castings manure (25 tons/ha) created the highest economic efficiency with total profit reaching 737,570,000 VND/ha/3 harvests while using worm castings manure at a rate of 5 tons/ha gave the highest real rate of return (3.26).