3-Indolebutyric acid is a chemical with the molecular formula C₁₂H₁₃NO₂. The pure form is a white crystalline solid. It is poorly soluble in water, with a solubility of 0.25 g/L at 20°C. It is readily soluble in benzene and soluble in other organic solvents.
Its vapor can form explosive mixtures with air, causing combustion and explosion when exposed to open flames or high heat. It can react with oxidants. Its vapor is heavier than air and can spread considerably farther at low altitudes. It can ignite and backfire when exposed to a fire source. Exposure to high heat increases the internal pressure of the container, posing a risk of cracking and explosion.
3-Indolebutyric acid is an indole plant growth regulator and an excellent rooting agent, promoting the rooting of cuttings of herbaceous and woody ornamental plants. It is commonly used for root-dip transplanting of woody and herbaceous plants, accelerating root growth and increasing the rooting rate. It can also be used for seed soaking and seed dressing to improve germination and survival rates. Plant growth regulators are synthetic, physiologically active organic compounds that, like plant hormones, regulate plant physiological processes and control plant growth and reproduction. Indolebutyric acid (IBA) and naphthaleneacetic acid (NAA) are two commonly used plant growth regulators for rooting cuttings. Indolebutyric acid is the most effective because it circulates less within the plant and tends to remain near the site of application.
In addition, combining a root-promoting growth regulator with another substance that facilitates its effectiveness can produce a synergistic or additive effect, potentially achieving more satisfactory results in plants with difficulty rooting. While indolebutyric acid has a strong rooting effect, it produces thin and long adventitious roots, while naphthaleneacetic acid (NAA) produces fewer, thicker roots. Therefore, combining the two often yields better results.
In 1928, F.W. Went first isolated the chemical messenger that causes coleoptile bending and named it auxin. In 1934, F. Kogl et al. identified it as indoleacetic acid. Therefore, indoleacetic acid is often used as a synonym for auxin. Shortly after the chemical book discovered that indoleacetic acid has growth-regulating effects, scientists discovered that indolepropionic acid (IPA) and indolebutyric acid (IBA) also have auxin-like physiological effects.
Later, naphthylacetic acid (NAA), 2,4-dichlorophenoxyacetic acid (2,4-D), 2,4,6-trichlorobenzoic acid, 4-amino-3,5,6-trichloropyridinecarboxylic acid, and some of their derivatives (including salts, esters, and amides, such as sodium naphthylacetate, 2,4-D butyl ester, and naphthylacetamide) were found to possess auxin activity.
3-Indolebutyric acid is not easily oxidized in plants and has poor conductivity. It has physiological effects similar to indoleacetic acid, affecting plant cell division and growth, but not as pronounced as indoleacetic acid. It is primarily used to promote rooting in cuttings and effectively stimulate cell division in the cambium. Its efficacy is long-lasting, resulting in numerous, slender adventitious roots. Its effectiveness is even better when combined with naphthylacetic acid. 3-Indolebutyric acid can be used for cuttings and rooting of chrysanthemums and other ornamental plants at a concentration of 0.5-1.0 mg/L, but should not be used on plant leaves. Degradation and Metabolism: Rapidly degrades in soil.
