BLOG POST: Is pink really the green fortune?

BLOG POST: I often get the question if plants can grow without sunlight. The background is that I, in my line of work at Plantagon, tell people how they could grow vegetables in the middle of the city, using no land and how to make it profitable. I'm Joakim Rytterborn, Head of Research & Development at Plantagon. Welcome to follow my blog posts! 

Since Plantagon started in 2008 we have developed our own patented technologies for vertical growing solutions. They are developed for industrial production and are scalable to match future demands. Beside this my role as Head of Research and Development has been to closely follow what happens within the field of closed environment vertical farming, identify the best ideas to be able to offer them to our customers. I’m proud to say that we now can offer solutions for every available spot in the city. – Please challenge us.

There has been a tremendous development within this field the latest years. All kinds of inventive growing solutions have emerged to solve the hassle with growing with increasing yields in closed environments. No soil is used, simply because it’s not sustainable and the plants don't need it. Instead different substrates are used to support the roots. Some of these substrates are reusable, like Pumice.

What is common with all closed environment systems is that the nutrients the plants need is dissolved in the water brought to the plants. The method of bringing the nutrient solution to the root however varies greatly between systems.

Mankind has always tried to increase the yield of our crops. 

The more we understand of what plants need the more we can enhance growth. A plant doesn’t only need nutrient solution to grow. Today we know that growth is determined by environmental factors, such as temperature, carbon dioxide in the air, and light. The more we can control these factors the more we can enhance growth.

Greenhouses were one early attempt to control the environment for the plant. Further development taught us to add the right nutrients and we also found that more light meant higher yields. To solve this, artificial lights was brought to the greenhouse in form of High Bay lighting. Those HPS- (High Pressure Sodium) and MH-lamps (Metal Halide) consumed lots of energy and produced heat, burning the plants if mounted close, but they enhanced growth.

This brings me to the answer “if plants can grow without sunlight”. Of course they can, light is actually photons (which forms when the electron in an atom changes state to a lower energy level, and thus losing potential energy, generated a photon with an energy supply, a light quantum, equivalent to the energy loss of the electron).

It does not matter if the light comes from a torch or the sun. What matters are the intensity and the color?

This area is were the most important break troughs enabling vertical farming has taken place. The LED has replaced the energy consuming High Bay lights making it economically viable to grow without natural light. Also researchers have found that the photosynthesis, which makes the plant grow, works most efficient with blue and red light. In fact it will grow with only blue and red wavelengths, why you could save even more energy not emitting all other wavelengths in white or natural light.

Red and blue light makes pink light.

You might have noticed that pictures from plant factories often come with this pink glow. The usually green plants now appear black because the leaves absorb all the light.

Is this the future? Is this the right way to go? Plants have evolved during millions of years under a full spectrum of natural light. How will the plants be affected by pink light?

We know today that you can affect the taste and appearance of a plant by changing the color of the light. But will it give the same yields or be as healthy for you.

Plantagon today takes part and sponsors research how different grow lights affects the nutrient content in the plant. This to find out if pink light really is the green fortune. Stay tuned for being the fist to know the result of this research.

Joakim Rytterborn,
Head of Research & Development at Plantagon

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The ideas and thoughts presented in this blog are my personal views and need not subscribe entirely to Plantagon.

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Please watch out for up-coming blog post by:

• Sepehr Mousavi, Sustainability Strategist, Plantagon and Chair to Swedish Standards Institute ‘Sustainable Urban Food Production’ committee
• Shrikant Ramakrishnan, Global Business Development Director, Plantagon