How are plant hormones used in agriculture and horticulture to control plant growth?

Sourav PanNovember 12, 2024

Answered

Plant hormones, or phytohormones, are essential for regulating various physiological processes in plants and are widely used in agriculture and horticulture to control plant growth and development. Here’s an overview of how these hormones are applied in agricultural practices:

1. Growth Promotion

• Auxins: These hormones promote cell elongation and division. They are extensively used in agriculture to enhance root formation in cuttings, facilitating vegetative propagation. Auxins also help regulate apical dominance, ensuring that the main shoot grows more vigorously than lateral shoots, which can optimize light capture and resource allocation.
• Gibberellins: Gibberellins stimulate stem elongation, seed germination, and flowering. They are particularly effective in breaking seed dormancy, promoting uniform germination in crops like barley. Gibberellins are also used to increase fruit size and improve crop yields by enhancing overall growth rates.
• Cytokinins: These hormones promote cell division and can delay leaf senescence (aging). Cytokinins are used to extend the productive life of plants, particularly in leafy vegetables and cut flowers, enhancing their marketability.

2. Fruit Ripening and Quality Control

• Ethylene: This gaseous hormone is crucial for fruit ripening. Ethylene is applied in the agricultural industry to control the ripening process during storage and transport, ensuring that fruits ripen uniformly. This application helps reduce spoilage and improves the quality of fruits available in the market.

3. Weed Control

• Synthetic Auxins: These are utilized as herbicides because they cause uncontrolled growth in weeds, leading to their death while sparing crops. This selective action allows for effective weed management without harming desired plants.

4. Seed Germination

• Gibberellins: These hormones are often applied to seeds to break dormancy and promote germination. This is especially useful for seeds that require specific environmental conditions to sprout.

5. Stress Tolerance

• Abscisic Acid (ABA): ABA plays a vital role in helping plants cope with abiotic stresses such as drought and salinity. It regulates stomatal closure to minimize water loss during periods of water scarcity, enhancing plant resilience.

6. Rooting and Propagation

• Auxins are commonly used as rooting hormones to promote root formation in stem cuttings, which is a standard practice in horticulture for propagating new plants from existing ones.

7. Delaying Senescence

• Cytokinins help delay aging processes in plants, extending their productivity and improving the quality of harvested crops by maintaining their freshness for longer periods.

8. Flowering Control

• Phytohormones like gibberellins and cytokinins can be manipulated to control flowering times, which is crucial for synchronizing flowering in crops for better yield management.

9. Research and Biotechnology Applications

• Understanding phytohormonal interactions has led to advancements in plant biotechnology, including genetic engineering approaches that enhance desirable traits such as stress tolerance and yield potential.