Sweet basil is one of the popular herbs that contains various types of antioxidants and is
widely used in pharmaceutical, food and cosmetic industries. Although sweet basil is considered as an
easy and fast-growing herb, yet, the production is still insufficient to cater to the rising demand. Thus,
the aim of this study is to increase biomass of sweet basil by the application of chitosan at d ifferent
timing. The experiment was arranged in Randomized Complete Block Design with four replications.
Plants were treated with different concentrations of chitosan (0, 2, 4 and 6 ml/L) at three different
times of application (20, 40 and 20+40 days after transplanting), and kept for 60 days under open field.
Data was analysed by using Statistical Analysis Software (version 9.4), Analysis of Variance was used
and means were separated using Least Significant Differences. Based on the findings, all treated plants
showed greater value compared to the control treatment. Among the treatments, it was found that
plants treated with 4 ml/L at 20 days after transplanting performed the best where the plants reached
highest stem fresh weight (44.59 g/plant), root dry weight (2.83 g/plant), leaf fresh weight (54.28
g/plant) and leaf dry weight (8.80 g/plant). The yield was higher than control treatment at 43.45% and
59.71% based on its leaf fresh weight and leaf dry weight, respectively. Therefore, it is recommended
for sweet basil to be treated with 4 ml/L at 20 days after transplanting. Besides, more details study on
compound profiling and its fraction from sweet basil leaf extract can be conducted in the future.