The Potential of Natural Plant Growth Regulators to Increase Vigor and Growth of Seeds Clove

Some problems in producing good quality clove seeds were the seed's slow growth and the absence of technology to accelerate its growth. Therefore, we performed the research to get one natural Plant Growth Regulator and its concentration potential to enhance clove seed growth. The study was arranged in a completely randomized design, with two factors and four replications. The first factor was five kinds of natural plant growth regulators (PGRs): (1) Leucaena leucocephala leaf extract (auxin source) + coconut water (Cytokinin), (2) Leucaena leucocephala seedling extract (auxin source) + coconut water, (3) gliricidia shoot extract + coconut water and (4) sprouted onion bulb extract (Eleutherine bulbosa) + coconut water. The second factor was the concentration of PGRs: (1) control (no PGRs), (2) 2.5 ml l⁻¹, (3) 5.0 ml l⁻¹, (4) 10 ml l⁻¹, and (5) 20 ml l⁻¹. Parameters observed were plant growth (plant height, leaf number, leaf length, leaf width, and stem diameter), the chlorophyll content of leaves, and the auxin and cytokinin content of each extract. Clove seedlings' growth was observed until four months old. PGRs from the extract of sprouted onion (Eleutherine bulbosa) and Gliricidia shoots could be developed due to their high auxin content, which can boost clove seed growth at the concentration of 10 ml l⁻¹.