How Does the Color of Light Affect Plant Growth?

Like water is to us human beings, light is to the plants. Without white light, there is no way these plants can undergo photosynthesis and produce food for themselves. Otherwise, they may wilt or undergo different botanical pathologies.

You might know that white light is an amalgam of different wavelengths of light, each with different colors. In fact, the rainbow is the extended version of white light when each wavelength is visible to the naked eye. Each of these wavelengths imparts a specific impact on different stages of plant growth.

In this article, we will walk you through the different stages of growth in plants and the importance of each wavelength in a respective growth period. Let us dive in!

Understanding Light Spectrum

We only think of the spectrum of light when the sun shines after a good pouring session because it is then that we see a rainbow. However, that spectrum is always around us, helping plants grow. The core reason we can only see the spectrum of colors after rain is that there is moisture in the air, which diffracts white light into its components.

You see a spectrum of colors ranging from reddish orange shades to deeper shades like bluish violet. The red color in this spectrum plays a crucial role in the growth of plants. Horticulturists have observed that plants grown under plenty of red light are taller in height and bigger in size. The red light also happens to affect the number of branches on a tree, the process of flowering and seed production.

On the flip side, the blue light enables the growth of stem cells and also fosters what is called apical dominance in scientific terminology. This apical dominance leads to increased budding and growth of more subsidiary branches.

That is how different wavelengths of white light can efficiently impact the growth of different parts of the plant. However, if you are planning to grow plants indoors, you will have to install the best LED grow lights that can cater to the needs of each plant part.

Make sure that the LED full specrum grow light system you install covers all the wavelengths of light. Nanolux is a brand that offers a spectrum of LED lights that play a crucial role in the growth of plants put inside a home. You can use their different series of LED lights that match your needs and requirements.

Blue Light: Essential for Vegetative Growth (400-500 nm)

Blue light lies between 400-500nm wavelengths of the spectrum. This color regulates the opening of stomata, which enables carbon dioxide absorption by the plant, which is crucial for the growth of the plant itself.

The blue light’s wavelength band encases high energy, which can have a pronounced impact on the growth of plants. Although the blue photons are high-energy packets, most of the energy is not consumed by the plants; hence, only low intensity of blue light is needed in vertical farming or indoor planting.

Blue light plays a significant role in the coloration of leaves; it makes the leaves greener. In addition to this, the blue light in certain plants, like lettuce, induces the production of certain vitamins and some antioxidants. Thus, for plants like these, blue light is important not only to give them their trademark color but also for their nourishment.

Also, blue light has been proven to have positive impacts on plant flowering. According to a scientific study, blue light was observed to enhance flowering, especially among long-day plants.

On the flip side, if blue light is obstructed or not provided to the plants growing in indoor gardening, it can lead to multiple disorders associated with plants. For instance, if tomatoes do not get enough of blue light, they may develop small blisters or intumescensces on stems, petioles and leaves. However with the induction of  blue light, one can regress the effect of these symptoms.

Red Light: Key to Flowering and Fruiting (600-700 nm

Over the period, red light has been proven to have a productive effect on the growth of plants. It is believed so because many scientific studies have concluded that plants absorb the most bandwidth of light between 600 and 700nm.

This implies that most photosynthesis is driven by red-colored light. Also, a smaller amount of red light is absorbed by other pigments, such as anthocyanin. As a result, red light is absorbed by the deeper tissues of the plant as well.

It has been observed that the plants grown in the abundance of red light are usually tall and large, with many branches that give them thickness. Another point of significance of red light in plant growth is that it elevates the production of plant hormone, meta-topolin, which resists the decomposition of chlorophyll. As a result, we get to see the greener leaves and stems of plants when the red light is abundant, especially in seasons like summer and spring.

Most importantly, red light plays its role in the fruiting and flowering part of a plant’s life cycle. It boosts the production of phytochromes, which in return signals the plant that it’s time for reproduction and flowering. The activated form of phytochromes trigger and regulate the transition of a green plant into a flowering plant, which later turns into fruitening phase.

Also, red light plays a significant role in regulating the circadian rhythms, which enable the plant to grow at the right time when all the extrinsic factors are in alignment. As a result, the plant’s growth efficiency is enhanced.

Far-Red Light: Enhancing Height and Light Response (700-800 nm)

Far-red light is known for enhancing the height of the stem, especially in rainforests where trees are dense and canopies block the sunlight. In areas like these, plants need more height to reach out to sunlight. There, far-red light steps in as a savior for the plants.

Furthermore, far-red light enables the plants to identify the low light caused by surrounding trees. This shadow will then stimulate or trigger the growth of the plant in terms of its height. As a result the plant is able to reach the sunlight without getting shadowed by the surrounding trees.

However, it is important that the plants are exposed to far-red light in a balanced quantity. An overabundance can lead to excessive elongation of stems or unwanted height, which may have certain side effects. One of these is that the stems get weaker, and they are unable to cope with the wind pressure.

Also, far-red light has its role in shaping the leaf angle, which in a broader spectrum implies that the wavelength within this bandwidth is important to determine plant morphology. It also broadens the leaf area which later proves to be useful in the absorption of more sunlight.

Green Light: Supporting Deeper Canopy Penetration (500-600 nm)

The green light is thought to penetrate deeper into the canopies, which is why we see green leaves and stems. It constitutes the 500-600 mm part of the light spectrum and is thought to reach deeper down through dense canopies.

The anecdote behind this thought of green light reaching the darker depths of canopies is based on the fact that we see colors that are reflected by the surfaces in our eyes. The leaves are green even under the dense filigree of the canopy, which proves that the greener part of light energy can reach these areas and, hence, reflect back to our eyes.

The green part of the light spectrum is crucial for plants also because the process of photosynthesis occurs within chlorophyll which is a green pigment. Recent studies have revealed that the green light is absorbed in the deeper tissues of leaves, which ultimately help chloroplast in the process of photosynthesis.

Full-Spectrum Lighting for Optimal Growth

Full-spectrum lighting is important to ensure the plant’s optimal growth. The full spectrum LED grow lights simulate sunlight and stimulates functions that are associated with each wavelength of light spectrum.

It ensures that the plant goes through each growth cycle from seedling to flowering stage. With full-spectrum lighting, plant growth can be elevated, and healthy growth can be ensured. Nanolux is among the best names that are dedicated to fostering vertical farming and greenhouses through its full-spectrum top LED grow light series. For instance, the LED SN Pro Series provides eight spectrum combinations and is flexible and easily adjustable. Also, these lights (630W/ 720W/ 860W/ 1000W/ 1200W)come with three dimming modes which helps alleviate vertical farming.

Conclusion

All in all, different wavelengths of white light play different yet crucial roles in the growth process of plants. From the seedling stage to the flowering and fruiting stage, each and every bandwidth of lightwave has a significant role in stem elongation, leaf color, canopy penetration, etc.

We know that each light color has its particular role in certain stages of plants’ life cycle. Hence, it goes without saying that each developmental phase requires a customized lighting setup. This ensures optimal and healthy growth of plants.

Therefore, it is very important that you put a thoughtful effort into selecting the right lighting setup for your vertical crop. In this regard, the easy solution for you is to visit the website of Nanolux and get yourself the best LED grow lights for indoor plants and vertical farming.