The science behind greenhouse plastic and flower colors

When we see a rose, it is normal to think of its color and appearance are defined solely by the variety. Even though the plant’s genes hold its potential, the greenhouse’s microclimate is what ends up determining how that beauty is expressed.

The quantity and quality of the radiation that the crop gets, the way it’s distributed can favor or limit the final quality of the flower. That’s why, at Grupo Plastilene we understand that the greenhouse covers are not only a barrier against rain, but an active technology that is capable of designing and managing the plant’s environment.

The physics of light: transmission, diffusion, and UV spectrum

Greenhouse plastic films are not simple transparent plastic sheets; they are technical filters that modify key properties such as:

• Transmission: Determines the total amount of radiation that goes through the film.
• Diffusion: Modifies the way that light is distributed. In a diffusion film, rays disperse in multiple directions to better reach the lower leaves in the crop.
• UV Spectrum: Manages the way that ultraviolet radiation passes to activate or inhibit the biological response
• Thermality: Helps manage the internal temperature by controlling infrared radiation.

Light is not managed the same in all regions

The diffusion needed varies depending on the geography. For example, in crops in Ecuador we tend to use films with a higher diffusion rate. Whereas, in several mountainous regions in Colombia, where clouds already act as a natural diffusor, a film with too much diffusion would reduce the light intensity during cloudy days. The goal is not to maximize light without any control, but to find the right balance for each microclimate.

How do covers influence the flower’s color?

A flower’s color, size, and uniformity can be influenced by the way in which the plant receives and processes light and UV radiation. However, not all varieties respond in the same way to this spectrum, which is why no one UV block level creates the same result in all crops.

At Grupo Plastilene we developed references with different UV block, transmission, and diffusion levels. This is especially important since UV radiation is part of the process related to pigmentation and natural mechanisms in the plant’s protection.

Depending on the flower and the result desired, the cover can manage this radiation in two ways:

• UV block: can be fundamental in crops such as bicolor roses and chrysanthemums, where it helps to prevent unwanted pigmentation or spots.
• UV aperture: some varieties require a higher exposure to this spectrum to support intense and characteristic color development.

That’s why choosing a unique cover because of its “transparency” means ignoring how complex this high value crop is. It also explains why using the same material for different varieties, for example, a recommended cover for a bicolor rose in a red variety could or could not provide the ideal conditions.

Designing for the crop, not for the greenhouse

An efficient thermal management does not solely depend on light passing through; the greenhouse design, ventilation, and specialized technologies such as Infralene, lets one control the infrared radiation and have higher thermal stability.

That’s why our support begins even before installation. The technical team at Grupo Plastilene evaluates agricultural variabilities such as crop type, variety, geographical location, light needs, and physical variabilities such as greenhouse structures, ventilation, and desired lifespan for the film.

Research and work from the origin

Our work begins even before flowers get to the commercial market. We work hand in hand with breeders from the development phase of new varieties to recommend the right cover.

Likewise, we promoted applied investigation. In Ecuador, we equipped the greenhouse of the Chimborazo Polytechnic’s research facility, supporting staff and students in the development of agricultural tests. These types of experiences allow us to go from questions like “what plastic do we use” to other more precise ones, like: what environment does this crop need to express its best potential?

An environment made to your crop’s size

There are no universal films. Behind a perfect flower there is an integrated analysis of transmission, diffusion, thermal behaviour, and UV radiation.

At Grupo Plastilene we summed it up with one idea: “it’s not just about covering a greenhouse, but designing the environment that the crop needs to express its best potential”

Are you looking for the best greenhouse film that fits your farm or crop? Contact us and discover the ideal solution for your production.