Can LEDs Affect the Taste and Smell of Your Crops?

There is no hiding behind the fact that commercial fruits and veggies aren’t cultivated and sold with the goal of maximizing their flavor. In the case of the now notoriously bland grocery store tomato, this is largely contributed to poor genetics. But while genetics do seemingly play the largest role in influencing flavor, it’s far from the only factor. Not surprising as flavor and aroma are often the centers of debate when comparing soil vs. hydroponics grow media.

But what about our lights? Does the sun influence our crops’ taste and smell? And if so, are our LED fixtures correctly replicating this influence?

Cannabis under Growers Republic LED Grow Lights

Without a doubt, the best way to explore whether LEDs and grow lamps, in general, are affecting our crops’ taste and aroma is by exploring the wavelength ranges they cast out. So let’s do exactly that!

Infrared (780-1000 nm)

There is a big debate over infrared light and its influence on crops. To help understand this spectrum better, you may want to think of it as heat radiation vs. light since it’s not visible to us, and these long wavelengths are a big way heat can transfer from one source to another.

LEDs do not traditionally feature notable amounts of infrared, unlike HID and T-Series bulbs. However, because this range can help plants bloom better and increase their growth, newer LED fixtures are starting to include them. However, it does not appear that infrared light affects the taste or smell of crops.

Verdict = Unlikely to influence crops’ taste and smell

Far-red (700-780 nm)

Introducing far-red light into your grow room is a game-changer for many cultivators.

However, far-red’s effect on taste and aroma is a bit of a mixed bag. A 2013 study found that when using red and far-red light together, the volatile profiles of tomato, strawberry, and blueberry increased, enhancing their flavor. However, much more recent 2021 research saw far-red increased unpleasant earthy and grassy flavors in sweet basil while blue/UV enriched sweet basil with an attractive citrus aroma and flavor.

Verdict = Likely to influence a crop’s flavor and aroma, but where it enhances, some it ruins others

Red Light (620-700 nm

While far-red has the potential to enhance plant taste and smell in crops, the red spectrum appears to largely stay away from influencing aroma or flavor. However, most agree that the red spectrum, especially in the bloom stage, is the most important spectrum for growing big ol’ crops with plentiful yields.

Even when you’re trying to enhance flavor and aroma by increasing the intensity of other spectrums, you still most likely want the majority of the light your plants receive coming from the red spectrum in the flowering stage.

Verdict = No noteworthy influence on taste and smell

Yellow-Orange (575-620 nm

This wavelength range does not have a notable influence on taste or aroma. However, it’s a great spectrum to point out when explaining why a LED often has favorable spectrums compared to HID bulbs like HPS.

Photosynthesis and a crop’s ability to absorb energy are largely driven by chlorophyll A and chlorophyll B. Both notably peak two times at different places with the blue range (400-500 nm) and orange-red range (600–700 nm) housing the 4 main peaks. HPS, the most popular grow lamp for years, peaks between 560 to 590 nm and at 815 nm wavelength. This largely falls outside of the greatest drivers for photosynthesis.

That’s why many LED fixtures are created to hone in on the chlorophyll peaks while still providing spectrums outside them that are also valuable for driving photosynthesis.

Verdict = No noteworthy influence on taste and smell

Green (500-575 nm)

I’m a big fan of the green light wavelength with its ability to deeply penetrate a plant’s canopy, potentially increasing yield. It may also have a synergetic effect with that wholly important far-red light spectrum. Then, it can be used when the main lights are off without disturbing a crop’s photoperiod. So a pretty cool spectrum, right! However, when it comes to affecting a crop’s aroma or flavor, green light seems solely passé. 

Verdict = No noteworthy influence on taste and smell

Blue-Violet (400-500 nm)

This wavelength range is probably the most looked at range when it comes to enhancing your crops’ flavor and aroma! It likely has the greatest influence of all the ranges. 

In fact, there is great interest and thought that by bringing intense blue light back the last few weeks leading up to harvest, one can majorly boost their crops’ quality (aroma, flavor, and nutritional value) one last time.  There is one caveat when it comes to switching your light fixture from a red-heavy one to blue -- you’re likely going to diminish the quantity of your yield. This happens because your crops only have so much energy they can expand, which has a limit we can’t currently push past. When you give your crops intense blue light, you’re driving their energy towards mechanisms that increase their quality instead of ones that increase their size.

Verdict = Enhances seemly all crop species’ taste and smell

UV-A (315-400 nm)

Kicking off our UV light range is UV-A. This is an exciting range because we know it can have huge effects on improving crop quality (aroma, flavor, and nutritional value) without being too harsh. That’s a big deal too, as you’ll see with the other harsher UVs.

UV light causes stress to the DNA of a crop and can “sun-burn” them just like it does us. And just like us, plants have defense mechanisms to protect themselves from this. Crops can create their own “sunscreen” by producing proteins and secondary metabolites — some crops can produce up to 15 unique defense proteins. These proteins and secondary metabolites (phenolic compounds, ascorbic acid, and carotenoids) directly enhance aroma, flavor, color, resistance to disease, and nutritional compounds like antioxidants.

Even with its DNA-stressing effects, using UV-A is considerably safer and less stressful for both plants and the gardener. Precaution should still be used with this wavelength range, but it’s significantly harder to overdo UV-A, unlike the next two.

Verdict = Likely to enhance most crop species’ taste and smell

UV-B (280-315 nm

An easy way to think of UV-B is that it’s a more intense version of UV-A light. So that probably means this range affects flavor and aroma too? You bet!

UV-B has been found to modify the flavonoid glycoside and hydroxycinnamic acid derivative profile in some crops. It does this by increasing compounds that appear to have high antioxidant activity. Both glycoside and hydroxycinnamic acid can directly increase flavor and aroma and even help our plants grow better.

Research has found that crops in the genus Brassica, in particular, are notable for having various positive reactions to UV-B. This includes several common crops, from broccoli to turnips. This alone can make UV-B a valuable spectrum for many gardeners.

Unlike UV-A, we need to be careful with this spectrum because too much can destroy plant DNA along with ours. 98% of UV-A light makes its way to the Earth’s surface, while less than 2% of UV-B light does. As well, too much UV-B can easily impair photosynthesis in the majority of crops. 

Verdict = Likely to enhance a crop’s taste and smell, but too light will impair photosynthesis in most crops

UV-C (100-280 nm)

UV-C will probably be the last spectrum on our list that a grower would want to add. In fact, you probably don’t want to add it — even if it might, in rare cases, help our crops. UV-C is completely absorbed by the atmosphere, meaning our plants aren’t naturally used to this spectrum, nor are we. UV-C can quickly cause extreme DNA damage to both us and our crops. 

Verdict = Potentially too dangerous to use but may increase secondary metabolites and phenolic content, however, this may only result in better resistance to diseases  

Can LEDs Affect The Taste And Smell Of Our Crops?

Like every grow light, from the classic HID bulb to the CFL, LEDs can and constantly do affect our crops’ taste and smell through the light spectrum it shines upon them.

Not all wavelength ranges like red or green influence flavor and aroma, and one range, as we saw, may even negatively affect them. 

However, that doesn’t mean we can ignore the select few that enhance our crops’ quality, from their taste to their smell to their nutritional content. By introducing these spectrums into our gardens, not only can we improve their quality, we can tell our crops how to grow, whether that’s short, tall, high-yielding, bursting with flavors, or a combination of all the above.

And with the new breed of LEDs coming out, even home growers starting for the first time, can now easily bring the sun into their grow room where it’s completely under their control.

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