Ethylene

Ethylene and Flowers: A love and hate relationship

Who does not like flower and fruit arrangements? The sensation of being so pleasing to the eyes, while able to inhale various scents from the fruit-flower combo, is truly mesmerizing. Despite the aesthetics they serve, it comes with a consequence, a limited flower life. With the astounding pairing, it could mean a beautiful death to flowers. Why? The answer is ethylene. Getting to know ethylene will help you make the appropriate selections in combining both flowers and fruits minus the harmful results.

 

Knowing more about Ethylene

An odorless, colorless gas, ethylene is a hormone from plants that is both natural and man-made. Often undetectable, plants are huge contributors to ethylene in nature. Products like flowers, fruits, and vegetables self manufacture ethylene and secrete it to the surroundings. Man-made ethylene is often used in industrial manufacturing.

Known as the ‘death’ or ‘ripening hormone’, ethylene shows an important role in various plant processes such as progress, development, and even death. Molecules of ethylene that are floating freely are absorbed by the receptors of plants.

 

What can Ethylene do?

Ethylene is proven to accelerate maturing and decay. Some practices contribute to a faster ripening of fruits and vegetables, like placing the crop inside the paper bag. The bag accumulates the secreted ethylene from the fruit, building heightened levels of the gas itself. The increasing levels of the gas will act as a catalyst so that the produce can secrete more. The gas is then reabsorbed and the cycle goes on.

Ethylene has established a reputation in the crops industry, as far as speed ripening is concerned. Bananas (usually picked green) are introduced with ethylene gas while in transit to ensure yellow bananas during arrival.

 

Its effect on flowers

Aside from being a catalyst for an accelerated ripening, there are other effects of ethylene on flowers that people should recognize.

• Weathering of buds and leaves
• Leaves turning yellow
• Leaf color becomes less saturated
• Falling off of flowers and their petals
• Bud openings are unusual
• Early death

With the proven benefits of ethylene to particular aspects of the industry, the effects above are not desired for fresh cut flowers. Over thirty percent of flowers die early due to the effects of the ethylene gas.

As a matter of fact, it takes a few parts of ethylene to harm flowers.

• A level of about 100 ppb (parts per billion) will cause harm within 24 hours and over.
• A level of about 250 ppb (parts per billion) will cause harm as fast as 12 hours.

As an example regarding ppb, about a hundred drops of food coloring in 26,400 gallons of water equates to 100 ppb. Therefore, a little ethylene can go a long way when it comes to harming flowers.

 

Which flowers are affected?

Not all fruits, flowers, and plants are severely sensitive to ethylene. They vary from one particular species to another. Take two types of red roses, for example, the Charlotte and Forever Young. The Charlotte is pretty sensitive than Forever Young to ethylene. In general, anti-ethylene products are given to flowers that are recognized as very sensitive to the gas. This guarantees an extended shelf life.

Another example is Gypsophilia (commonly known as Babies Breath) and Carnation. They are both treated with anti-ethylene products since they are really sensitive. The Carnation’s case would allow the flower to increase its shelf life by 3 to 4 times. Though to an extent all flowers are affected by ethylene, some are considered overly sensitive to it some of which are as follows:

·         Achillea ·         Agapanthus ·         Allium ·         Anethum ·         Astrantia ·         Bouvardia ·         Campanula ·         Celosia ·         Chelone ·         Cymbidium ·         Delphinium

·         Dendrobium ·         Echium ·         Freesia ·         Gladiolus ·         Gypsophilia ·         Helianthus ·         Ixia ·         Kniphofia ·         Lily ·         Lisianthus  ·         Monkshood

·         Orchids *** ·         Physostegia ·         Ranunculus ·         Roses *** ·         Saponaria ·         Silene ·         Snapdragon ·         Sweet Pea ·         Trachelium ·         Trollius ·         Wax Flower

 

Note: *** Not all varieties of these flowers fall under the Ethylene-sensitive category

 

How to minimize the effects of ethylene?

Solutions were created to minimize the effects of the gas in flowers. Occasional applications for homes are not useful. For it to be successful and less harmful, a material is needed that absorbs the ethylene – Guerite.

The University of South Florida has conducted more than 2,000 hours of tests and found out that Guerite can absorb up to 5 percent of its mass in ethylene and eleven percent in water. This mineral is widely used to extend the duration of foods in some storing products.

Since temperature is a vital aspect, sensitivity to ethylene at temperatures below 4^oC (40^oF) is not of concern. Primarily, it is one of the explanations why keeping the “cold temperature chain” is crucial regardless the levels of production and distribution, from harvest to retail purchase.

It is best not to put flowers close to plant produce or sources that manufacture ethylene gas.

 

Ethylene comes from the following sources:

• Crops (Citrus, Water-rich fruits, Berries, Tropical Fruits, etc.)
• Propane boilers
• Gas propelled machines that produce exhaust fumes
• Lighted cigarettes
• Older flowers
• Bacteria and Botrytis

 

Simple rules that are to be followed:

• Do not place flowers in close contact with fruits or vegetables.
• Do not place flowers in areas where they are to exposed to smoke or fumes from any gas-propelled machinery
• Older flowers should stay away from the freshly cut or picked ones.
• Placing flowers in high temperature areas is not advisable.