The Influence of Gibberellins and Smoke Water as a Stimulant for Germination and Vegetative Growth of Syzygium aromaticum (L.) Merr. & L. M. Perry

Clove or cengkeh (Syzygium aromaticum) is one of Indonesia’s commodities with high domestic and international potential, considering that this plant is used as raw material for the cigarette industry. Therefore, it is necessary to optimize the production of Indonesian cloves, one of which is by using growth stimulators such as plant growth regulators (PGR). This study uses gibberellic acid (GA3) and smoke water as exogenous growth triggers. The treatment given was soaking S. aromaticum seeds in gibberellic acid (GA3) and liquid smoke for 24 h. The GA3 concentrations used were 100 ppm, 75 ppm, 50 ppm, and 25 ppm. Smoke water was obtained from the pyrolysis of coconut shells, and the concentrations used were 0.5%, 1%, 2%, and 3%. Observations were conducted for 11 weeks and divided into two phases, namely the germination phase and the vegetative growth phase. Parameters measured included germination percentage, radicle, and plumula length in the first phase, root length, plant height, and number and area of leaves in the second phase. The best results were achieved with the soaking treatment using 0.5% smoke water, which showed a significant increase in all observed growth parameters. This is due to the content of karrikin in smoke water, which acts like a growth hormone and triggers the performance of other growth hormones. In addition, karrikin plays an active role in the germination process by changing the morphology of the seeds.