The Emerson effect is a phenomenon related to photosynthesis that shows how certain wavelengths of light work together to increase the photosynthetic efficiency of plants. Discovered by Robert Emerson in the 1950s, this effect revolutionized our understanding of how plants use light to produce energy. Its relevance is not only scientific, but also practical, especially in crops that seek to maximize productivity, such as indoor crops or cannabis.
In today's article, from Grow Industry we are going to talk to you about what the Emerson effect is and how it can help the growth of your plants.
Introduction to the Emerson effect: What is it and how did it arise?
Definition of the Emerson effect
The Emerson effect refers to the increase in photosynthetic efficiency when plants are exposed to two specific wavelengths of light simultaneously. These lengths correspond to the far red (more than 680 nm) and at red (about 680nm). When both lengths are combined, a mechanism is activated in the plants' photosynthetic systems that generates more energy than when they are used separately.
This discovery demonstrated that photosynthesis processes depend not only on the intensity of light, but also on its spectrum. This has been key to optimizing lighting in growing systems and increasing plant performance.
Historical context and discovery
The effect is named after Robert Emerson, an American biologist who, in his experiments with chloroplasts, identified how red and far-red wavelengths increased oxygen production in plants. This finding challenged the belief that photosynthesis was saturated with red light, showing that far-red plays a crucial complementary role.
Emerson's studies not only helped to better understand the processes of photosynthesis, but also laid the foundation for developing modern lighting technologies for crops, especially in controlled environments.
The different light spectrums for growing marijuana
Growing marijuana relies heavily on providing plants with an adequate light spectrum during each stage of their growth. Each range of light within the electromagnetic spectrum has a different impact on plant development, from germination to flowering. Here we explore the main light spectrums and their importance to maximize the yield and quality of your crop.
Infrared (800 nm – 1 mm)
Infrared, although invisible to the human eye, has a significant impact on the heat and metabolism of the plants. This spectrum does not directly contribute to photosynthesis, but influences the perspiration and in temperature regulation, which affects overall growth. Additionally, infrared can improve stem elongation, causing plants to grow taller and with more space between nodes.
When growing indoors, too much infrared can generate unwanted heat, forcing growers to use efficient ventilation systems. However, in controlled amounts, this spectrum helps plants to adapt better to the environment and to improve its structure.
The far red light spectrum (700 – 800 nm)
Far red is essential during flowering stage, as it stimulates key processes such as cell expansion and flower production. This spectrum is also related to the Emerson effect, which improves photosynthetic efficiency when combined with near red light. Plants exposed to far red tend to produce denser buds with better resin quality.
Furthermore, far red regulates the circadian cycle of plants by influencing the response to phytochrome, helping plants to distinguish between day and night. This is especially useful in controlled crops where the aim is to optimize light and dark times.
Near red (600 – 700 nm)
The near red spectrum is crucial in both the vegetative and flowering stages. This range of light stimulates photosynthesis, promoting leaf growth and biomass production. In the flowering stage, it enhances the formation of large, heavy flowers, making it an essential spectrum to maximize productivity.
Near red light also has a positive effect on the synthesis of antioxidants and terpenes, improving the aromatic profile of the buds. It is one of the most used wavelengths in modern LED systems due to its direct impact on plant growth and quality.
Green/yellow light (500 – 600 nm)
Although green and yellow light were thought to have little relevance to plant growth, recent research has shown that contributes to photosynthesis in deep layers of the leaves, where other spectra do not easily reach. This light range improves light penetration into the canopy, which benefits the lower leaves and encourages balanced growth.
The green/yellow light also plays an important role in the visual appearance of plants, helping growers detect problems such as nutrient deficiencies or pests. In multispectral lighting systems, this range is included to complement the benefits of blue and red.
Blue light (400 – 500 nm)
The blue spectrum is essential during vegetative stage, since it regulates the compact growth of plants and encourages the production of strong and healthy leaves. This range of light is primarily absorbed by chloroplasts, making it key to photosynthesis in the early stages of development.
Additionally, blue light stimulates the production of antioxidants and secondary compounds, which improves plant resistance to diseases and environmental stress. In indoor crops, it is used to prevent plants from stretching too much, promoting a more robust and efficient structure.
Ultraviolet light (400 – 10 nm)
The ultraviolet spectrum, although not essential for photosynthesis, has a significant impact on the resin and terpene production in marijuana. Controlled exposure to UV-B, in particular, stimulates plants to produce more protective compounds such as cannabinoids, resulting in more potent buds with a richer aromatic profile.
However, UV light should be used with caution, as excessive exposure can damage plants and slow their growth. In adequate amounts, this spectrum improves the overall quality of the product, especially in crops intended for resin extraction.
Each light spectrum has a specific impact on marijuana development, from vegetation to flowering. Understanding how to take advantage of these ranges and adjust the lighting according to the needs of the plants is key to achieving abundant and high quality harvests. In modern growing, multispectral LED systems are the perfect tool to optimize each stage of growth.
How does the Emerson effect work?
Relationship with photosynthesis
Photosynthesis, the process by which plants convert light into chemical energy, occurs in two main systems: the Photosystem I (PSI) and the Photosystem II (PSII). Each of these systems responds to different wavelengths of light. The Emerson effect occurs when PSI absorbs far-red light and PSII absorbs red light, creating a synergistic effect which increases the efficiency of the photosynthetic process.
This discovery demonstrated that the two photosystems do not function in isolation, but rather cooperate to maximize light harvesting and energy production.
Interaction between wavelengths of light
The interaction between red and far red is the basis of the Emerson effect. When both light spectrums are present, greater electron transfer is achieved between the photosystems, which increases oxygen production and, therefore, the amount of energy available to the plant. Without this combination, photosystems do not reach their maximum performance.
This phenomenon has been fundamental to understand why plants need a balanced light spectrum and how to take advantage of this information to improve crop lighting.
Importance and benefits of the Emerson effect in plant cultivation
Optimizing light for crops
The Emerson effect has transformed the way crop lighting systems are designed, especially in controlled environments such as greenhouses and indoor grows. Multispectral LED lights, for example, incorporate both red and far red to replicate the solar spectrum and take full advantage of the Emerson effect. This allows a better plant growth, even in conditions where natural light is limited.
The use of specific light spectrums not only improves photosynthesis, but also reduces energy consumption, making crops more sustainable and efficient.
Improvement in photosynthetic efficiency
Thanks to the Emerson effect, plants can use more energy from the available light, which results in faster growth and a increased biomass production. In commercial crops, this translates into better performances without the need to increase the cultivation area or production time.
Additionally, this phenomenon allows growers to adjust lighting conditions to influence other factors, such as flower development or cannabinoid profile in the case of cannabis.
Benefits of the Emerson effect in cannabis crops
Increase in biomass production
In cannabis cultivation, the Emerson effect translates directly into a greater weight and quality of flowers. By optimizing photosynthesis, plants grow more vigorous and produce denser, more resinous buds. This is especially important in commercial crops, where quality and quantity are key factors.
Use of multispectral LED lights
Modern lighting technologies, such as multispectral LEDs, are designed to take advantage of the Emerson effect by including red and far-red light spectrums. These lights allow growers to control the intensity and quality of light, adjusting it according to the plant's growth stage, whether vegetative or flowering.
Improved cannabinoid and terpene profile
The Emerson effect not only improves overall plant growth, but also influences the quality of the final product. By optimizing photosynthesis by combining red and far-red light, plants can produce higher concentrations of cannabinoids such as THC and CBD, as well as more complex terpene profiles. This results in more powerful buds with intense aromas, ideal for both medicinal and recreational use.
Reduction of cultivation time
Taking advantage of the Emerson effect can also accelerate the growth cycle of plants, since greater photosynthetic efficiency allows plants to accumulate energy more quickly. This means you can get harvests in less time without compromising quality, a crucial advantage in commercial crops or in projects where time is an important factor.
The Emerson effect is a crucial phenomenon for understanding how plants maximize their photosynthetic efficiency by taking advantage of specific wavelengths. Its application in modern agriculture, especially in crops such as cannabis, has allowed the productivity, sustainability and quality of crops to be improved.
Do you want to maximize the yield of your crops? In Grow Industry, we have a wide selection of LED lighting systems designed to take advantage of the Emerson effect and ensure optimal growth.
Visit us at our physical stores in Reus and Vilafranca del Penedès or consult our website to equip yourself with the most advanced tools for your crops. Take your production to the next level with Grow Industry!
