The effect of LED grow light on plant senescence

Chlorophyll degradation, rapid protein loss, and RNA hydrolysis during plant senescence are mainly characterized by leaf senescence. Chloroplasts are hypersensitive to the change of surrounding light. The red light, blue light, and red-blue mixed light are conducive to the formation of chloroplasts. Blue light is helpful to increase the starch granules in chloroplasts. Red light and far-red light inhibit the development of chloroplasts. The red-blue light can boost the synthesis of chlorophyll in cucumber seedling leaves and also delay the attenuation of chlorophyll content in the later stage. This effect is more obvious with the decrease of red light ratio and the increase of blue light ratio. The chlorophyll content of cucumber seedlings under LED red-blue combined light treatment was significantly higher than monochromatic red and blue light treatment. LED blue light could significantly increase the chlorophyll a/b value of black-spotted and green garlic seedlings.

COB  LED red-blue combined plant grow light

During the leaf senescence, the content and activities of cytokinin (CTK), auxin (IAA), abscisic acid (ABA) are changed. Different light qualities have different effects on phytohormones. CTK stimulates leaf cell growth, promotes photosynthesis, inhibits the activity of ribonuclease, deoxyribonuclease and protease, and slowdowns the degradation of nucleic acids, proteins and chlorophyll, hence slowing leaf senescence. IAA is principally centered in the region where growth is strong. Violet light can increase the activity of indoleacetic oxidase, and low IAA levels prevent elongation. ABA is generally produced in senescent leaf tissues, mature fruits, seeds, stems, and roots. Compare with the white light and blue light, the red-blue LED grow light will decrease the ABA content of cucumber and cabbage to a greater extent.

Peroxidase (POD), superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) are important and photoconductive protective enzymes. In the process of plant aging, the activity of these enzymes will decrease rapidly. The effects of different light qualities on the antioxidant enzyme activities of plants were significant. Illumination rapeseed seedlings for 9 days with red light, APX activity increased significantly and POD activity decreased. After 15 days of red and blue light irradiation, the POD activity of tomato was higher than that of white light 20.9% and 11.7% respectively. After 20 days of green light treatment, the POD activity was the lowest, only 55.4% of white light. For cucumber seedling leaves, blue light can obviously boot the soluble protein content and increase the activities of POD, SOD, APX, and CAT. Furthermore, the activity of SOD and APX gradually decreased with the extension of illumination time. The activity of SOD and APX under blue light and red light decreased slowly but were always higher than white light. Red light irradiation significantly reduced the activity of IAA peroxidase in tomato leaves, such as peroxidase, IAA peroxidase, and eggplant leaves, but caused the peroxidase activity of eggplant leaves to increase significantly. Therefore, the use of reasonable LED grows light strategy can effectively delay the aging of plants.

Blue light chip in the white light LED

In normal conditions, white light LEDs have a blue light source. An ordinary white-light LED is consisted of the blue-light LED chip and the fluorescent substance. It works very simply, that is the chip illuminates blue-light to the fluorescent powders to emit the white light.

Whit light SMD LED

In the 1960s and 1970s, red and green LEDs were successively created. However, the blue-light chip has still not been invented, for it has greater photon energy, and is difficult to grow blue-light materials. Due to the difficulties and cost, a lot of institutes quit. However, two Japanese researchers who keep working at it and eventually invented blue-light LEDs for the first time in 1989. At that time, the light was very weak and had no practical application value, but it gave people hope of developing blue-light LEDs. Finally in 1993, a staff of Nichia, Nakamura Shuji invented the high-brightness blue-light chips technology. Thanks to this technology, the white light LED lighting has really stepped out of the laboratory into practical production and application. Today we can conclude that, without the blue-light chip, white-light LEDs is extremely hard to popularize.
There is some date show the influences that the blue-light LED brought to our lives and environment. According to relevant information, the worldwide annual electricity consumption is about 200 billion kWh, of which about 19% is used for lighting. Imagine if all incandescent lights (electrical conversion rate of about 10%), fluorescent lights (electrical conversion rate of about 30%) are replaced with white LED energy-saving lights (electrical light conversion rate of 50% or more), then a minimum of 1.52 billion kWh of electrical energy is saved on a yearly basis. Furthermore, it reduces coal consumption by about 500 million tons, reduces carbon dioxide emissions by about 1.3 billion tons, and reduces sulfur dioxide emissions by about 4.2 million tons. These tangible data highlight the significance of the blue light LED.

Effects of LED Grow Light on Nutritional Quality of Fruits and Vegetables

The proteins, carbs, organic acids and vitamins in fruits and vegetables are good for human health. Light quality can influence the content of VC in crops through controlling the activity of VC synthesis and decomposing enzymes, in addition, to regulate the protein metabolism and carbs buildup in horticultural plants. Red light stimulates the accumulation of carbs, and blue light is helpful to protein structure, while the mixture of red and blue light has an appreciably greater influence on the nutritional quality of plants than single color light. For lettuce, LED red or blue light can decrease the nitrate, applying blue or green light can boost the amount of soluble sugar, and replenishing infrared light is effective to promote the VC synthesis. For tomato growing, blue light LED grow lights can enhance the content of VC and soluble protein. The mix of red and blue light and red light can increase the value sugar and acid. Furthermore, red and blue combined light can raise the VC content in

LED plant grow light with red and blue combined light

cucumber.
The phenolic substances, flavonoids, anthocyanins and other substances contained in fruits and vegetables do not merely have a significant effect on the color, flavor and commercial value of vegetables and fruits as well as have natural antioxidant activity, which can effectively inhibit or eliminate free radicals in human body. The use of LED grow lights with blue light can truly improve the anthocyanin of eggplant by 73.6%, while utilizing of LED red light, red and blue mixed light can increase flavonoids and total phenolic content. Blue light can increase the content of lycopene, flavonoids, and anthocyanins in tomato. The combination of red and blue light advances the creation of anthocyanins but prevents the synthesis of flavonoids. In contrast to the white light LED plant lights, red light can enormously boost the anthocyanin content in the upper part of lettuce, nevertheless, the blue light treated lettuce has the lowest anthocyanin content. The entire phenolic content of green leaf, purple leaf, and red leaf lettuce had greater amounts under white light, red and blue combined light, and blue light, but the smallest value under red light. Supplementing LED UV or orange light can raise the value of phenolic compounds in lettuce leaves while providing green light can increase anthocyanin content.
Consequently, the effective use of LED grow lights with suitable color is a useful method to enhance the nutritional quality of facilities fruits and vegetables.

Matters needing attention for LED strips installation

In the marketplace and on the web, many people sometimes asking why the LED strips' brightness is lower, the lifetime is shorter in the abnormal range than the theoretical value provided by the supplier. There are various causes of this condition, apart from some dishonest businesses sell seconds at best quality prices, the incorrect use is the major factor. Therefore, it is necessary to pay our attention to numerous issues during install for the LED lights.

Firstly, the wiring way of LED light strips. The most of LED light bars are adopt input voltage of DC12V or DC24V, which must be powered by the matching power supply. The total power must be greater than the sum of the connected LED lights. The wiring of the LED tapes needs to be correctly welded by anode and cathode. Commonly, LED light strips producers will clearly mark the anode (+) and cathode (-) beside the bonding pad as well as solder the wires in one end or both ends. Furthermore, if you want to save money on the power supply, there is a cost-effective choice that you can parallel connect the LED strips, and just need a matched high power supply.
The second thing is the connection of the controller. RGB LED lights need to connect with the controller to realize various lighting effects. The three chips in the RGB LED usually share one positive pole, so the RGB LED tapes to have one "+" bonding pad and three "-" bonding pads. Different controllers have different control distance. The farthest distance of ordinary controller is 10 to 15 meters, some better controllers are about 20 meters and the best's remote distance up to 30 meters.
Last but not least, the total length of the LED strips. In most cases, we suggest a parallel connection, for the overlong series connection length, will case the brightness reducing and excess temperature. LED lights' working lifetime will be dramatically reduced in the excessive temperature condition.
Consequently, at the time of installation, we must follow the relevant instructions and requirements.

Influences of LED plant lights on the horticultural plants

The control of light on plant growth includes seed germination, stem elongation, leaf and root improvement, phototropism, chlorophyll synthesis and decomposition, and flower induction. The light environment features in the facility include illumination intensity, photoperiod, and spectral distribution. The man-made supplemental light can direct controls these light features without being affected by the weather.

Plants absorb specific light and use different photoreceptors to identified different light signals. At present, there are three types of photoreceptors are found in plants, including a Photosensitive element (absorbing red and far-red light), Cryptochrome (absorbing blue light and near-ultraviolet light), and ultraviolet light receptors (absorbing UV-A and UV-B). Illuminating the plants by LED plant grow lights with particular wavelength can boost the photosynthesis, increase the growth and improvement of the plant.
Photosynthesis mostly applies red-orange light (610-720nm) and blue-violet light (400-510nm). It can be realized by LED manufacturing technology that emitting single color light with a particular wave crest according to the wavelength band that the chlorophyll has the strongest absorption. Nowadays, based on relevant experiments, we knew that the red-orange light will benefit the plants' growth, dry matter's accumulation, organic formation, as well as promote precocious flowering and fruiting. The Blue-violet light can regulate the phototropism of leaf, boost stomatal opening, chloroplast activity and boost organs development, meanwhile inhibit stem elongation, control over growth and postpone flowering. The red and blue mixed LED grow lights have a lot of advantages that the single color light have not, it can release the specific spectrum that basically facilitates photosynthesis and morphogenesis. The energy efficiency is outstanding and the light energy utilization is able to get 80% to 90%.
In the facility gardening production, LED plant grow lights have a great promoter action. In the entire growing period of time, controlling light quality, intensity, and lighting period by LED plant lights, can lessen the growth cycle, enhance the yield, nutritive value and form value of agricultural products, as well as realize efficient, economical and intelligent manufacturing of facility horticultural plants.

The difference between high power and low power LEDs

LEDs are the pointolite, different from compact fluorescent and incandescent lamps in the marketplace. The pointolite, as the name suggests, is a light source that glows evenly from a point to the surrounding space.

Generally, the specifications of most low-power LEDs are 0.1 watts, 0.2 watts, and 0.3 watts, of which a 0.3 watt LED's luminous flux reach up to 45lm. Therefore, we call the LED with a power of 0.5 watts or more as the high-power LED, of which a 0.5 watt LED can reach up to 60 lm and a 1 watt LED's maximal luminous flux is 110 lm. That is the difference in lumination between the two.

If you're looking for lighting products that apply to your house, then the low-power LEDs will be satisfactory, but in advertising lighting, outdoor lighting and other public lighting, high-power LEDs would be a better choice.

Economically, the price of high-power LEDs is commonly more expensive. High-power LEDs have higher energy consumption, higher lumination, and more heat production. In order to ensure the reliable quality and long working lifetime, LED lights manufacturers must use materials with high heat dissipation efficiency and superior quality, such as gold wires, copper-bases, highly conductive PCB and so on.

With the progress of relevant production technology, the LED with power exceeding 200 watts can be manufactured by the LED lights factory. However, the cost performance of these ultra high-power LEDs is too low to popularize. Presently, the LED strip lights with 0.5 watt LEDs is one of the top sellers LED strips, for its moderate price, high brightness, good heat dissipation, and wide applicability. The LED strips made of 0.5 watt LEDs can be applied to indoor lighting, outdoor lighting, advertisement lighting etc.

Applying LED plant grow lights on the vegetable seedling

LED source of light control vegies morphogenesis and growth is a vital technology in greenhouse planting. The plant can perception and assimilate light through photoreceptor systems. After that, transported to control morphological changes by intracellular messengers. Photomorphogenesis is counted on light to regulate the differentiation, structure, functionality and the production of tissues and organs.

Plant seedlings are a significant portion of facility agriculture. Uninterrupted drizzly weather conditions lead to lack of light and unnecessary growth, that will affect the growth of greens, bloom bud differentiation, and fruits improvement, and finally influence the yield and quality. A number of plant growth regulators are accustomed to managing the growth of seedlings on stream, however, the false usage will cause toxic contamination.

LED plant grow lights have several positive aspects in the supplement of light, it can be an achievable method to increase seedlings. Based on the experimental information, in the low light environment, the green light LED grow lights can accelerate the growth of cucumber seedlings. In contrast to the low light, the red and blue light improved healthy index 151.26% and 237.98% correspondingly. Furthermore, compared to single color light, the healthy index enhanced by 304.46% by the used composite light of red and blue light. Red light can boost the amount of leaf, dry and fresh quality, leaf area, stem dimension, plant height, healthy index, SOD activity, root activity and soluble protein content of cucumber seedlings.

In comparison with natural light, LED red light and blue light can highly raise the leaf area, dry matter quantity and a healthy index of tomato seedlings. LED green light can truly enhance the biomass of cucumber and tomato seedlings, and the health index, stem diameter, and fresh-dry quantity of seedlings with the enlargement of green light intensity. LED red and blue mixed light can improve the stem diameter, leaf area, plant dry weight, root-shoot ratio, and healthy index of eggplant.

The above shows the benefits of vegetable seedlings cultivated by applying LED grow lights are very noticeable.

The secrets of LED lights' Color Temperature

Heating an ideal blackbody, when the temperature continues rising, the color of blackbody starts to change from red to blue progressively. If the color of a LED and blackbody is the same, we utilize the value of temperature at this time to symbolize the color temperature of the light source.
Because the CCT (correlated color temperature) is not really an equivalent color, but an assessed value of the performance of the LED when the LED color approaches the blackbody color. That is why two different type LEDs have the same CCT may still look like differences in the appearance of light color. In addition, there is no essential relationship between CCT and CRI (color rendering index). It's improper to evaluate the color rendering ability of LED lights simply by color temperature.
In the industry of the white-light illumination, most suppliers divide the white light into warm white, white and cool white based on the feeling of humans.
When the CCT is under 4000K, this reddish light is called warm white, for it gives people a warm, comfortable feeling. The second part, it goes up to the interval of 4000K to 6500K. People have no specific feeling about this color in visual and emotion, so the CCT in this range is called neutral light or white. As soon as the color temperature is higher than 6500K, the light will turn blue gradually and creates a cold atmosphere, so it is named cool white.

Moreover, people's sense is as well affected by the brightness. The dimmed cool white light will give people a feeling of dismal. Likewise, the warm white light with excessive brightness will make people feel muggy. 
Consequently, it is important to customize different LED lights based on various purposes and customers, in order to correspond with market trends. We, MLDR, the China LED strips supplier are able to manufacture all types of LED light strips and offer wholesale, customized, OEM, ODM services.

The causes of LED light decay

LED light decay means that after a long time of use, the brightness of LED lights will have different degrees of dimming, which is the light decay of the LED lights.

Today, the LED lighting made by diverse LED suppliers will have different light decay. Even high-power LEDs have light decay that has an inseparable relationship with working temperature. It is decided by chip, phosphor and packaging technology. Nowadays, the lumens decline of LED lights is one of the hot concerns for the LED light industry. There are 2 key reasons for the light decay of LEDs:

First of all, the quality of LED lights:
1. A few LED lights manufacturers select the low quality LED chip to cut the cost, which makes the lumination of such lights are attenuated faster.
2. The producing technique is flawed, the heat made by the LED chip's working can't be released from the PIN efficiently, which bring about the overtemperature and light decay.

Secondly, the working conditions:
1. The LED is ordered to be driven by a constant current. However, in practical use, many customers will use voltage driven that cause the LED decay to increase.
2. The actual input current is higher than the rated current of LEDs.

Actually, there are lots of causes of the light decay of LED lights. The foremost crucial problem is the efficiency of heat dissipation. Many LED lighting suppliers do not focus on the heat dissipation of their lights, the light decay of these LED lights will over others with the well cooling design after a long period of use. The heat resistance of the chip, the cooling effect of the PCB, the base, the colloid, the gold wire, and other materials are also associated with the light decay of LEDs.

At present, the LED lighting market is paying more and more attention to the quality of LED lights. As the LED light strips and LED plant grow lights supplier in China, we also use the mature manufacturing technology and select excellent raw materials to guarantee the reliable quality of our products.

What do these numbers on the LED lights mean?

When choose and buy LED lights, we are able to frequently notice some numbers from the product information like 2835, 3528, 5630, 5050 etc. What do all these numbers signify? What are the differences between them?

Actually, all these numbers are utilized to point out the dimensions of SMD LEDs that usually mounted on the LED strips, LED tapes, TV backlights, LED bulbs and other LED products. One example is 2835 means the length of the SMD2835 LED is 2.8mm and the width is 3.5mm. But it is necessary to underline that all these are the metric unit. The following is specific explanations:

3528: the dimensions of SMD3528 LED is 3.5*2.8*1.9mm, the last number 1.9mm is the value of thickness. Generally, the operating current of SMD3528 LEDs is 20mA, and the maximum is 40mA. In addition, 3528 also called as 1210 in countries and regions where British unit is used.

2835: the size is 3*1.4*0.8mm. It is possible to mix up 2835 and 3528, for they are really similar and their PCB is normally universal. Compare with SMD3528LEDs, SMD2835 LEDs have higher brightness, better heat dissipation, as well as cheaper. Consequently, SMD2835 LEDs are occupying a huge market share nowadays.

5050: The size is 5*5*1.6mm. The workmanship of SMD5050 LED is excellent, for an SMD5050 LED has 3 chips. Based on this feature, producers install 3 chips of various colours are red, green and blue respectively in a LED. And then, we are able to realize change colours by control the current of different chips, which is the RGB LED.

5630: The size is 5.6*3*0.9mm. The SMD5630 LED has high lumination, even light, low light decay, and long lifetime. According to the power of, SMD5630 LEDs are usually categorized as 0.2W, 0.3W and 0.5W, of which a 0.5W SMD5630 LED can reach 60lm.

SMD LEDs

There are still have a large amount of SMD LED with other sizes like 3030, 4014, 7030, 8520 etc. Nowadays we should know that all these numbers are the size of SMD LEDs. LED lights suppliers will pick suitable LEDs depending on the various demands of customers. For example, as the LED tapes manufacturer, we will select 0.5W SMD5630 LED when some clients asked for high brightness. But if some demand the even light and higher CRI, the SMD2835 LED certainly is the better choice.

For more information about specifications of LEDs, please read another post that talks about common specifications of LEDs. The web link is as follow:

Let you know the LED specifications and parameters in three minutes.

Let you know the LED specifications and parameters in three minutes

The LED is one of the solid-state semiconductor devices that transform electric power into light. As the most common source of light, do you know the specifications of SMD LEDs? In this post, we intend to introduce a number of usual specifications of SMD LEDs as well as its meaning.

SMD5630 LEDs

1. Voltage: the SMD LED utilizes a low voltage power. The one LED input voltage is between 2 to 4V. Take the LED flexible strip RU5630G as an example, its 3 SMD5630 LEDs and 1 resistor connected in series as a group, using 12V input voltage. This kind of LED lighting with low voltage design is actually safer and is especially suited to public places.

2. Current: the rated current of SMD LED differs based on the power. Generally, the illumination of LEDs will go up along with the increase of current in a certain range.

3. Power: the normal SMD LED rated power is 0.2W, 0.5W, 1W and 1.5W etc .

4. Color temperature: White LEDs are divided into warm white (2700-4000K), white (5500-6000K), cool white (7000K or more). Red, blue and green is denoted with the optical band: Red (600nm-680nm), Green (500nm-580nm), Blue (430nm-480nm).

5. Beam angle: the commonest beam angle of SMD LED is 120 degrees. In most cases, LED strips suppliers changes the beam angle by mounting the lens on the LED light strips. Such as the MFS3030A LED curtain light's beam angle is increased to 175 degrees by installing the PMMA lens on it.

6. Luminous flux: commonly, the higher power of LED implies the higher brightness. For example, the SMD2835 LED of 0.2W is about 24lm, the SMD5630 LED of 0.5W can attain 60lm, and also the SMD3030 LED of lattice curtain light can attain 150lm.

7. CRI: its complete name is Color Rendition Index, representing the capability to restore the object color, and the highest value is Ra100. For a more specific explanation of CRI, please refer to another article: Full-spectrum LEDs, the healthy lighting.

If you want to get more information on LED lighting, please bookmark our website: www.mldrled.com. We are the professional LED strip lights and LED grow lights manufacturer in China, and will update the latest products and articles on this website regularly.

The differences between rigid and flexible LED strips

With the improvement of LED light technologies, LED light products have become the leader in the illumination market, because of its eco-friendly, energy-efficient, multipurpose and cost-effective. Numerous places across the world have progressively replaced traditional lights with LED lights. As the experienced supplier in China, we will provide you with a simple summary of LED strip lights, hoping that'll be useful to you.

LED light strips including flexible LED strips and rigid LED strips.

Firstly, flexible LED strips, also called LED tapes or LED ribbon, which manufactured by mounting the LED on the FPCB, and its thickness of the flexible LED strip is merely about 1mm. LED flexible strips are soft and coated with double-sided adhesive on the backside, convenient for installation in corners, rounded and abnormal areas. Moreover, the majority of the LED strips can be changed the length by cutting and lengthening. Applications of LED tapes are as follow.

1. The building shape lighting.

2. The decoration of the irregular object, like the irregular wall and the ceiling in hotels, clubs and KTVs etc.

3. Indoor decorative lighting, such as the doorframe, counter and cabinet etc.

4. Vehicle decorations.

5. Showcase and others.

Another one, rigid LED strip lights or LED hard strip lights. The only difference between the flexible and the rigid is that the hard strip light utilizes the rigid PCB with the material of aluminum or fiberglass. The strengths of LED rigid light strips are that it is easy to fix and install, the length can be customized based on usage requirements, and it has the higher heat-dissipation effect. The shortcomings are it can't be bent freely. Not suited to irregular places. Widely used in Jewelry showcase lighting, cabinet lighting, wardrobe lighting, store decoration lighting, art lighting, lightbox lighting, and house decoration lighting.

The most widespread on the market today are 12V and 24V LED strip light that is harmless to people. Definitely, there'll be covered by plastic profiles or tubes if the input voltage is AC 110V, AC 120V and AC 220V etc, for enhancing the safety performance of high-voltage LED strip lights. The ordinary lifespan is over 30,000 hours and the operating temperature is -30°C to 60°C. Categorized by colors, LED lights are usually separated into single color and RGB. The single color LED strips including red, green, blue, cool white, white, natural white, warm white. The RGB LED strips are color changeable by controlling 3 chips with different colors. There are also various other light strips available on the market, like RGBW, three-colors and so on.

In the above introduction, I think that everyone has an over-all idea of LED lights.

Nowadays, LED lighting suppliers not just simply concentrating on lighting efficiency or product lifespan, and also more attentive of people's perception and the effect of light on consumers, dedicated to producing man-made light nearer to normal daylight. Along with the improvement and maturity of the LED technology, full-spectrum LEDs have grown to be the hot zone in the field, which is resemble the sunlight spectrum.
During the sunny daytime, the sun sends out a continuous spectrum of light, as well as its colour temperature is 5000K to 5500K. The value of CRI (colour rendering index) symbolizes the capability of the source of light to redisplay the colour of the object. Fifteen types of sample colours, R1 to R15 were utilized to appraise the colour rendering of the source of light. R9 is utilized to judge the redisplay quality of the brilliant red. The CRI of sunshine is identified as Ra 100. The full-spectrum including the spectrum of ultraviolet light, visible light and infrared light, of which the proportion of the visible light part resembles the daylight, as well as the CRI is near to Ra 100.

The parameter of R2835FS LED tapes

Above is the spectrum of 2835 full-spectrum Led strip lights Art. No. R2835FS. From that, we are able to know the Ra and R9 of the full-spectrum LED strips is 98.0 and 99 correspondingly, meaning the superior quality. The LED strips, with the broader colour range, not only make the colour of the item appear much more authentic, but also successfully decreases the risk of blue light.
In accordance with market data, the actual percentage of full-spectrum LEDs in the LED industry is also tiny. In contrast to normal LEDs, the price of full-spectrum LEDs is actually a bit higher.
Business insiders anticipate, with the steady development of full-spectrum technologies, far more customers will certainly understand the significance of full-spectrum light quality, as well as its business will increase quickly. The whole LED market, mainly indoor illumination will change from traditional high colour rendering LEDs to full spectrum LEDs.