Ethylene (Ethene) Gas: What is it and why do we care?- a quick EXPLANATION for flower farmers
What is Ethylene?
Ethylene is one of the most widely used and produced gases in the chemical industry. It is the simplest alkene (a molecule consisting of carbon and hydrogen with a carbon-carbon double bond). In the “scientific world,” ethylene is called ethene. Ethylene has a broad range of uses- spanning agriculture, manufacturing, and science.
Ethylene (ethene) gas is a molecule made up of two carbon and four hydrogen atoms.
A Brief But Interesting History of Ethylene:
Coal gas, also known as illuminating gas, was the primary fuel source behind street lamps in the 19th century. Plants did not grow well around the street lights. With this in mind, a scientist realized that pea seedlings near the lighting in his laboratory were also having growth issues. Upon further investigation, the scientist found that ethylene was a component of illuminating gas. After this, numerous tests and experiments were performed with ethylene- including the discovery that it is actually a hormone that can greatly impact the growth, performance, and longevity of plant material.
Where Do We Find Ethylene Around the Home and Farm?
Ethylene can be created during the breakdown of many fruits and vegetables (lots of ethylene is created during the process of composting!) Some fruits and vegetables (such as apples, avocados, bananas, and tomatoes) are classified as “Ethylene producers” and will emit ethylene. There are many fruits, vegetables, and flowers (like tulips) that are particularly sensitive to ethylene.
Great infographic explaining the effects of ethylene gas on different fruits and vegetables. Credit: UC San Diego Center for Community Health.
Interestingly enough- ethylene can also infiltrate the soil and cause growth issues in numerous plants. Ethylene can cause elongated stems, curved leaves, curled stems, and all sorts of other wacky growth issues. While researching this aspect of ethylene, my mind immediately went to a specific tulip variety we grew this past season- Sambuca. This particular variety was incredibly beautiful- but had a very unique and interesting growth habit. Sambuca presented nearly all of the aforementioned symptoms- Could there be a case of ethylene overexposure in these tulip bulb fields? Is that even a thing? Could it be? Now I’m curious… Hmmm…
So Why Should I Care About Ethylene as a Flower Farmer?
Many flowers need to be refrigerated after they are harvested. What do many people keep in their refrigerators? Fruits and vegetables.
Many of our customers keep their flowers on their kitchen counter which is often close to what? The family fruit bowl? Is random produce hanging out on the counter?
Well- all these fruits and vegetables sitting around our flowers can be emitting ethylene gas- causing the flowers to prematurely bloom, wilt, or lose their petals. That’s why we urge farmers and consumers to keep fresh-cut flowers away from produce that may be emitting ethylene gas. Alternatively, ethylene-based products have been developed and manufactured to help “ripen” different foods and flowers which have to be picked when incredibly under-ripe.
Farmers and growers who need to keep their flowers around the same area as foods or around compost may want to invest in an ethylene detector to monitor levels and keep them in check. Products like ethylene absorbing sachets can work as a preventative measure in situations where there may be low levels of ethylene gas.
Other “Fun Facts” About Ethylene and Flower Farming:
Exhaust from vehicles and on-farm machinery can emit ethylene gas.
Smoke can also be a source of ethylene - (This makes me wonder about the recent wildfire smoke hitting the Northeastern United States from the Canadian wildfires and how that may be affecting the horticultural industry right now)
Plants can create ethylene internally when they sustain stress- like from physical damage or dehydration. For example- if a bucket of flowers is knocked down on the floor, that bucket of flowers may create ethylene internally which may impact the vase life of those flowers- and eventually the flowers around them.
Bacteria and fungi in dirty water buckets can also emit ethylene gas. Another reason to keep those water buckets nice and clean!
Some flowers (like tulips) are especially sensitive to ethylene gas. Other flowers- like lilies- have some ethylene-resistant qualities. This is one of the reasons why lilies are considered a non-wilting flower- something that makes us love and appreciate them so much!
Fusarium is a fungus that can negatively impact crops like tulips and lisianthus. Fusarium can also produce and emit ethylene gas.
All of this research into the science behind ethylene gas has me asking a lot of questions about how we could possibly use this knowledge as a tool to benefit us here on the farm and in the floral industry as a whole. For example- Can we put an overripe bunch of bananas next to a bunch of under-ripe lilies to help them open just in time for a last-minute event? Of course it’s not that simple… but… What would that look like? How would that work? What would that do? Hmm… I wonder….
Do you have any questions or comments to share about ethylene? I’d love to hear them! Feel free to share in the comments below.
-Karissa
Sources:
Q&A: How do plants respond to ethylene and what is its importance? - Caren Chang
Ethylene Exposed - Gay Smith
Ethylene Sensitivity of Tulip Cultivars - Bill Miller, Susan Liou and Simon de Waard Cornell University
