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June 19, 2024Complete guide and benefits in agriculture
Auxins are essential plant hormones for the growth and development of plants. These phytohormones regulate vital processes such as cell elongation, root formation, flowering, and fruit set. In this article, we will explore in depth what auxins are, what they are used for, and how they are utilized in agriculture to improve crop yields.

What are
auxins?
Auxins are a type of plant hormone that play a crucial role in regulating the growth and development of plants. Among the most well-known is indoleacetic acid (IAA), although there are other natural and synthetic forms that are equally important.
Function of
auxins in plants
Auxins play a fundamental role in various physiological processes in plants:

Regulation of growth and development
Auxins act on various physiological levels, promoting cell elongation and division.
Cell elongation: They facilitate cell elongation by increasing the plasticity of the cell wall, a vital transformation for the growth in length of stems and roots.
- Cell division: They directly influence cell division by activating genes that regulate the cell cycle in meristematic tissues where active growth occurs.

Root formation and rooting of cuttings
Induction of adventitious roots: Auxins stimulate the formation of adventitious roots from non-root parts, useful in vegetative propagation.
- Rooting in cuttings: They are essential for the rooting of cuttings, as they promote a robust root system that supports new independent plants.

Promotion of flowering and fruit set
Flower formation: They influence flower formation, working alongside other plant hormones to induce flowering, useful in synchronizing bloom times.
- Fruit development: During fruit set and development, auxins stimulate cell growth in the ovary of the flower, improving fruit size and quality.
For more detailed information about the importance of auxins in plant development and their application in agriculture, we recommend reading the full article available on SciELO.
Types of
auxins
Auxins are divided into two major groups: natural and synthetic.

Natural auxins
- Indoleacetic acid (IAA): It is the most common and widely studied auxin. It is produced in the meristematic areas of the plant and regulates processes such as cell elongation and responses to light and gravity.
- Phenylacetic acid (PAA): Although less common than IAA, it also plays a role in promoting plant growth and development.
- Indolebutyric acid (IBA): Found in smaller concentrations, it is primarily used in root formation, especially in the vegetative propagation of plants.
- Auxinic phenols: Include compounds such as p-hydroxybenzoic acid and p-coumaric acid, which have auxinic activity in various plants.

Synthetic or chemical auxins
- Naphthaleneacetic acid (NAA): Used in agriculture for its effectiveness and stability, it promotes rooting and controls the shape and size of plants.
- Indolebutyric acid (IBA): Amazingly effective in inducing rooting, used in plant cloning and to improve the quality of ornamental plants.
Obtaining and application of
auxins in agriculture
Auxins play a crucial role in modern agriculture, being fundamental in their acquisition and appropriate application to maximize crop growth and development.
Seaweeds:
a natural source of auxins
We have seen that auxins, especially indoleacetic acid (IAA), are found in various parts of plants, but they are also generated in other plant species such as seaweeds, from which they can be extracted using biotechnological processes to incorporate them into crops, ensuring greater plant development in a sustainable and environmentally friendly way.
However, not all seaweeds have the same index and quality of auxins, and not all extraction systems are effective in achieving a high concentration of auxins.

Application and
dosage in crops
Auxins can be applied in many ways depending on the type of crop and the application method:
- Seed treatment: Improves germination and initial vigor.
- Foliar application: Promotes overall growth and development of the plant.
- Rooting of cuttings: Promotes the formation of adventitious roots.


Benefits of using
auxins in agriculture
The use of auxins in agriculture offers multiple benefits:
- Improvement of rooting and root formation: Strengthen the root system, improving water and nutrient absorption.
- Promotion of crop growth and development: Stimulate stem, leaf elongation, and regulate apical dominance for uniform growth.
- Prevention of fruit and flower drops: Prevent premature drops, ensuring higher yields.
- Relationship with other plant hormones: Auxins interact with gibberellins, cytokinins, ethylene, and abscisic acid to coordinate plant growth and development.
For more information on how biofertilizers improve plant growth, you can check this article from SciELO (Mexico).
Examples in
different crops
Auxins have outstanding practical applications in diverse types of crops:

Fruit trees
Improve fruit formation and development, prevent fruit, and flower drops, and increase fruit size.

Vegetables
Stimulate rooting, promote fruit set, and control flowering.

Cereals and legumes
Promote uniform growth, improve pod fixation, and stimulate root development.
Conclusion
Auxins are a powerful tool in modern agriculture. Understanding what auxins are used for and how to apply them correctly can make a significant difference in crop yield and quality. Integrating these plant hormones into agricultural practices allows farmers to significantly improve their results by promoting healthier and more efficient plant growth. Ficosterra has developed advanced technologies such as TRD that alloobtaining high-quality natural auxins from seaweeds of the Laminariaceae family, contributing to more sustainable and effective agricultural practices.
For more information on the use of natural auxins in agriculture and how they can benefit your crops, you can contact our technical department at ensayos@ficosterra.com.
Frequently asked questions
about auxins
Auxins are plant hormones responsible for the growth and development of plants, regulating processes such as cell elongation, root formation, and apical dominance. Their main function is to regulate cell growth through elongation and division. Additionally, they participate in processes such as phototropism (response to light) and gravitropism (response to gravity).
Auxins are primarily produced in the apical meristems of stems and growth buds, but they can also be found in other parts of the plant such as young leaves and developing fruits.
Auxins are transported in a polar, basipetal manner, meaning from the synthesis zones downwards through the phloem in the form of complexes with carrier proteins.
Auxins can stimulate cell elongation, promote the formation of adventitious roots, inhibit the growth of lateral buds, induce the formation of flowers and fruits, and participate in responses to environmental stimuli.
Light, gravity, contact with other plants, environmental stress, and the application of growth regulators can influence the concentration and distribution of auxins in the plant.
Auxins are used in agriculture to promote rooting of cuttings, control plant growth, induce the formation of seedless fruits, and improve crop production. Additionally, they are used in gardening to stimulate the growth of new roots in newly transplanted plants, minimizing shock and increasing survival rates.
Auxins promote cell elongation by stimulating the production of proteins that loosen the cell walls, allowing cell expansion. They also regulate the cell cycle, influencing cell division and the growth of new tissues. Auxins are responsible for phototropism (growth towards light) and gravitropism (response to gravity).
Auxins stimulate the formation of fruits from the ovaries of fertilized flowers and participate in the maturation and abscission (fall) of fruits and seeds. They also influence seed germination, an essential process for the propagation of plant species.
The regulation of synthetic auxins in the European Union (EU) is primarily framed by Regulation (EC) No 1107/2009, which establishes the standards for the authorization, marketing, and use of plant protection products. There is increasing control over doses, application methods, and safety precautions.
Therefore, the EU is promoting the development of sustainable and environmentally friendly alternatives to traditional plant protection products, including research on natural auxins derived from seaweed.
