Stay up to date with our latest developments and plant protection news—anytime, anywhere.
Ethephon—The Cotton Ripener: What You Need to Know
Apr 21,2026
Ethephon is an organic compound; in its pure form, it appears as white needle-like crystals, while the industrial product is a pale brown liquid. It is readily soluble in water, methanol, acetone, ethylene glycol, and propylene glycol; slightly soluble in toluene; and insoluble in petroleum ether. It is utilized as an agricultural plant growth stimulant. Ethephon is a high-quality, highly effective plant growth regulator that exerts various effects, including promoting fruit ripening, stimulating latex flow, and regulating sex differentiation.
Ethephon is formulated as a 40% aqueous solution. It remains stable in aqueous solutions with a pH below 3.5; however, as the pH rises, it undergoes hydrolysis to release ethylene gas. It is sensitive to ultraviolet light but remains stable at temperatures below 75°C.
Application Requirements for Ethephon
- 1. Crop Requirements: Ethephon spraying is generally recommended for cotton fields characterized by excessive vegetative growth (remaining "green"), delayed maturity, strong late-season growth potential, and an abundance of late-setting bolls. For optimal results, ethephon application to cotton should be timed so that the majority of the bolls in the field have reached an age of over 45 days.
- Temperature Requirements: At the time of application, the maximum daily temperature must exceed 20°C. Furthermore, following application, the maximum daily temperature must remain above 20°C for approximately 15 days to ensure effective results. For the primary purpose of accelerating cotton boll maturation, a 40% ethephon aqueous solution is typically applied via spraying at a rate of 70–100 milliliters per *mu* (approx. 0.067 hectares). Generally, the application of ethephon accelerates boll cracking, reduces the occurrence of late-blooming flowers (which are susceptible to frost damage), effectively improves cotton fiber quality, and ultimately boosts cotton yields.
- Dosage Requirements: The specific dosage of the pesticide should be determined based on the cotton's growth vigor, the prevailing daily temperature, and the timing of the application (early or late in the season). For cotton fields exhibiting vigorous growth, where application occurs late in the season, temperatures are relatively low, or where rapid field clearance is required, the dosage should be increased appropriately—though the maximum application rate must not exceed 100 milliliters per *mu*. Conversely, under other conditions, the dosage should be reduced accordingly. When spraying, aim the nozzle directly at the green bolls on the cotton plants and apply the solution evenly from top to bottom, ensuring that all bolls targeted for maturation are thoroughly coated with the liquid.
- Spraying Method: Application should be performed on a sunny day with either calm conditions or a gentle breeze; spraying is permissible during the morning, midday, or evening hours. As ethephon is a strong acid, it is imperative to employ the "secondary dilution" method when preparing the spray mixture. Particular attention must be paid to the sequence in which ingredients are added to the spray tank; when tank-mixing ethephon with defoliants (such as those based on Thidiazuron), ethephon should generally be added *after* the defoliant to prevent premature neutralization reactions. Furthermore, the mixture should be prepared immediately before use, as it is prone to losing its efficacy if allowed to sit for an extended period.
Precautions when using Ethephon
1. Once diluted, ethephon solutions exhibit reduced stability due to a decrease in acidity; therefore, ethephon mixtures should be prepared immediately before use.
2. Ethephon should be applied during sunny weather conditions. If rainfall occurs within six hours of application, the treatment must be reapplied after the rain has ceased.
3. Technical-grade ethephon is an irritant to human skin and eyes; therefore, appropriate safety precautions for personal protection must be observed during application.
4. Do not be misled by hearsay or unreliable claims into purchasing counterfeit or substandard products. In recent years, a wide variety of crop-ripening agents have appeared on the market
Related Information
Knowledge Base
Ethephon—The Cotton Ripener: What You Need to Know
Ethephon is a cotton ripening agent. What precautions should be taken when using it, and what are its usage requirements?
Apr 21,2026
Knowledge Base
What is the mechanism of action of indoxacarb, and which pests does it control?
Indoxacarb is a broad-spectrum insecticide effective against a wide range of pests on crops such as cereals, cotton, fruit trees, and vegetables. It is primarily used to control cabbage butterfly larvae, diamondback moths, beet armyworms, and cotton bollworms.
Apr 09,2026
Email:info@pandustry.com
WhatsApp：+86-15729389816
Tel.:+86-371-60383117
Add: 3F, Building No.9, National University Technology Zone(East), Zhengzhou , Henan, China
Leave a Message
Demand for agrochemical products or crops