Ethylene

Ethylene is a natural gaseous phytohormone that regulates vital physiological processes in plants, including seed germination, flowering, fruit ripening, and leaf senescence. In agricultural practices, it is rarely applied as a pure gas; instead, producers utilize ethylene-releasing agents, such as ethephon, which decompose within plant tissues to release ethylene in a controlled manner.

Ethylene is classified as a plant growth regulator. Unlike herbicides that kill weeds or fungicides that protect against pathogens, ethylene is used as a management tool to influence the development cycle of the plant. It allows farmers to control the timing of harvest, improve the uniformity of fruit ripening, and manage the structural growth of plants.

The mechanism of action involves the activation of specific ethylene-responsive genes. This process triggers the expression of enzymes that degrade cell walls and starch, facilitating the conversion of starch into sugars and the breakdown of chlorophyll. These biological changes lead to fruit softening, enhanced color development, and the eventual abscission of leaves or fruit.

Application is widespread across various crops, such as tomatoes, bananas, apples, and grapes, to ensure uniform ripening. In cereal crops, it is applied to strengthen the stalk and reduce lodging, thereby protecting yield potential. Furthermore, it is extensively used in cotton production to accelerate boll opening, which is crucial for efficient mechanized harvesting.

• Optimal temperatures range between 15°C and 25°C.
• Avoid application during heat stress or periods of drought.
• Strict adherence to application rates to avoid plant injury.
• Use appropriate personal protective equipment (PPE).

Safety precautions are essential when handling ethylene-releasing formulations. Because these products can induce rapid senescence or abscission, they must be applied at the precise physiological stage of the crop. Improper use may cause plant stress, reduced fruit quality, or excessive leaf drop, highlighting the need for careful calibration and professional agronomic supervision.