Jakub Kobylarczyk
1 pDP AP
20.02.2021
The effect of medical laser on certain plants
The purpose of my experiment is to show that thanks
to the biostimulation laser plants are able to grow
faster.
When you will try to do this experiment use the
biostimulation laser just to illuminate the plant at the
time given below and not your face, body.
Will medical laser irradiation affect the growth rate of
Desmostachya bipinnata and date palm?
1
Background research
I chose biostimulation laser because 6 years ago when I was abroad I saw that a
man who took care of his plants and sold them was illuminating plants by some
laser. I didn’t know why but now I know because I talked to the scientist in
Krakow whose name is Jan Dobrowolski who knows medical lasers and said
that it is probably a biostimulation laser so I wanted to do this experiment
using exactly this laser. This experiment was interesting for me from the very
beginning because I wanted to check if it would work.
Demostachya bipinnata is a tufted grass growing up to 150 cm tall with coarse
leaves, a thick scaly central rhizome and long lateral rhizomes. It is a tropical
plant which grows in northern Africa and tropical Asia. The plant is grown as a
soil stabilizer. I chose this grass because it’s easy to seed. It grows quickly so
you won’t have to wait for the effects of experiment very long. Demostachya
bipinnata is cheap and widely available in garden shops.
Date palm is a tree cultivated for its sweet edible fruits. The date palm has
been prized from remotest antiquity because the fruit has been the staple food
and main source of wealth in some regions. Now date palms are grown in the
Canary Islands, northern Africa, the Middle East, Pakistan, India, Mexico, and
the U.S. state of California. I chose date palm to this experiment because it is
tropical, maybe it doesn’t grow as fast as Demostachya bipinnata but I assumed
that when it grows to a certain size I will finish the experiment, it is easy to
plant and replanting is not difficult at all, to get the seeds you have to only go
to the grocery store and buy dates. I really like this plant so I'll leave some at
home after the experiment and give some to my friends
I think that the outcome of the experiment will be positive and the
biostimulation laser irradiation will accelerate the growth of these plants. I
predict this will be because I have already done a similar experiment but on
non-tropical plants and the result was positive. I did it tremendous help of
some people so I decided that I want to do this experiment with a different
medical laser and on other plants and completely alone. Maybe I will do it
again but also on different basis.
2
Question
Will medical laser irradiation affect the growth rate of Desmostachya bipinnata
and date palm?
Variables
TABLE 1. Table showing independent and dependent variables in the experiment
Independent Variables
Dependent variable
Duration of biostimulation laser
irradiation on plants. Five trials will be
done with the following irradiation
times:
1. 0s
2. 3s
3. 6s
4. 7,5s
5. 9s
Number of times of irradiation:
1. In the first group which I won’t
irradiate is equal to 0.
2. In all other groups it will be 3.
Number of days for Desmostachya
bipinnata will grow to 40 cm and date
palm will grow to 30 cm.
Controls
Seeds – fresh shop dates and typical seedlings of Desmostachya bipinnata from
a garden store will be used throughout the entire experiment.
Biostimulation laser – I will use in this experiment biostimulation laser model
LT-3 because I have access to the laboratory where I can use this laser and it
has to be biostimulation laser.
3
Sunlight – All the seeds will receive the same amount of access to sunlight.
They will stay in the same area throughout the whole experiment, it means
that there will be no difference between groups. The amount they receive can’t
be measured, but as it is the same, it will not be a factor in any difference
between the results of each test.
Temperature – The temperature of the seeds’ environment will be controlled
by keeping the seeds in the same place. That means there won’t be any
variations in temperature between them. This will keep the temperature of the
water constant.
Substrate – The soil used for the experiment was the same for all plants. It was
a potting soil.
Amount of water – All the seeds will be receiving the same amount of water
and they will be given 120 mL of water at planting.
Water – The water used on the seeds will be sourced from the same tap for the
whole experiment because it will reduce any variation in levels of chlorine
other substances. The water will also be in the same temperature.
Materials









5 x Desmostachya bipinnata seeds
5x date
15 litres tap water
10 x pots 10x15cm
Biostimulation laser (or access to use it only at the beginning of the
experiment)
Hendi 500 mL measuring jug
Black marker pen
PlantPlus All Purpose Potting Mix
LENIAR 50 cm ruler
TABLE 2. Table showing the uncertainty for the equipment used in the experiment
Equipment
Hendi 1 litre measuring jug
Hendi 500 mL measuring jug
Uncertainty
Around 20 mL
Around 10 mL
4
Method
1. Four seeds of Demostachya bipinnata were illuminated with the
biostimulation laser, one for 3 seconds 3 times, second for 6 seconds 3
times, third for 7,5 seconds 3 times and the last one for 9 seconds 3
times. Four seeds of date palm were illuminated in the same way.
2. Four seeds of Demostachya bipinnata were marked with numbers from 2
to 5 using a marker pen and the same with four seeds of date palm.
3. Five pots of Demostachya bipinnata and five pots of date palm were
marked with numbers from 1 to 5 using a marker pen to indicate which
plant was illuminated with biostimulation laser for how many seconds.
4. Each pot was filled with potting mix to a depth of 3 cm.
5. Five Demostachya bipinnatas and five date palms were placed in each
pot that have been pressed into the soil to be covered by the potting
mix.
6. 500 mL measuring jug was filled with 100 mL tap water then poured
over the substrate in pot marked 1 for Demostachya bipinnata.
7. 500 mL measuring jug and was filled with 100 mL tap water then poured
over the substrate in pot marked 2 for Demostachya bipinnata.
8. This procedure was repeated 3 more times but to the pot marked 3,4
and 5.
9. Steps 6 to 8 were repeated but instead of pots with Demostachya
bipinnatas for date palms.
10. Plants length was checked daily with a ruler until one of the
Demostachya bipinnatas reached 40 cm and one of the date palms
reached 30 cm.
5
Results
TABLE 3. Table showing which Demostachya bipinnata grew the fastest in a given weeks, 1
means the fastest, 5 the slowest
Week
First plant
not illuminated
Second plant
Illuminated for
3 seconds 3
times
Third plant
illuminated for
Demostachya 6 seconds 3
bipinnatas
times
Fourth plant
illuminated for
7,5 seconds 3
times
Fifth plant
illuminated for
9 seconds 3
times
I
II
III
IV
1
3
5
5
2
1
1
1
3
2
2
2
4
4
3
3
5
5
4
4
TABLE 4. Table showing which date palm grew the fastest in a given weeks, 1 means the
fastest, 5 the slowest
Week
Date palms
First plant
not
illuminated
Second plant
Illuminated
for 3 seconds
3 times
Third plant
illuminated
for 6 seconds
3 times
Fourth plant
illuminated
for 7,5
seconds 3
times
Fifth plant
illuminated
for 9 seconds
3 times
I
II
III
IV
1
2
4
5
2
1
1
1
3
3
2
2
4
4
3
3
5
5
5
4
6
Observations
In the case of Demostachya bipinnatas at the beginning, the grass that wasn’t
illuminated with laser grew the fastest but in the following weeks it began to
change and ultimately the grass that was illuminated for the shortest amount
of time was the fastest. Second was the grass which was illuminated for 6
seconds, then for 7,5 seconds, then for 9 seconds and the last was the grass
that wasn’t illuminated.
In the case of date palms at the beginning as in the case of Demostachya
bipinnatas, not illuminated palm grew the fastest but eventually it was the
same and the date palm that was illuminated for 3 seconds was the fastest,
seconds was the palm which was illuminated for 6 seconds, third was the palm
which was illuminated for 7,5, then for 9 seconds and the last was the palm
that wasn’t illuminated. Exactly the same like in case of Demostachya
bipinnatas.
Processed Data
TABLE 5. Table showing which grasses reached 40 cm, 0 means that it didn’t reach, 1 means
that it reached
Week
Not illuminated
Illuminated for 3
seconds
Illuminated for 6
seconds
Illuminated for
7,5 seconds
Illuminated for 9
seconds
I
II
III
IV
0
0
0
0
0
0
1
0
0
0
1
0
0
0
1
0
0
0
0
7
TABLE 6. Table is showing which date palms reached 30 cm, 0 means that it didn’t reach, 1
means that it reached
Week
Not illuminated
Illuminated for 3
seconds
Illuminated for 6
seconds
Illuminated for
7,5 seconds
Illuminated for 9
seconds
I
II
III
IV
0
0
0
0
0
0
0
1
0
0
0
1
0
0
0
0
0
0
0
0
GRAPH 1. Graph showing which plants reached the goal (date palms have grown by 30 cm/
Demostachya bipinnatas have grown by 30 cm
Which plants reached the goal?
1.2
1
0.8
0.6
Demostachya bipinnatas
Date palm
0.4
0.2
0
Not illuminated Illuminated for Illuminated for Illuminated for Illuminated for
3 seconds
6 seconds
7,5 seconds
9 seconds
The graph shows that plants that were illuminated growths faster but too much
is not healthy because those that were illuminated for 9 seconds and date palm
that was illuminated for 7,5 seconds didn’t reach the goal like not illuminated
plants.
8
Evaluation
You have to be careful when using biostimulation laser but the experiment
itself is very enjoyable to perform. I’m sure someday I will still try to do this
experiment on other plants and by using another lasers, there are many
possibilities to do a similar experiment. I will also check if, for example, after
such an irradiation with a laser after some time nothing happened to these
plants, if not then the experiment is showing something new because I have
not come across before that someone irradiated plants with a laser to make
them grow faster. I recommend trying to do the similar experiments on other
plants and I’m very curious about other results.
Conclusion
In conclusion, the results of this experiment indicate that the illumination by
biostimulation laser for 3 seconds is the best for the speed of growing plants. I
expected that laser irradiation would accelerate plant growth but I didn’t
expect it that actually for 3 seconds.
At the beginning, when the not illuminated plants were growing the fastest, I
was disappointed but then I was positively surprised. Laser irradiation has
significantly accelerated the development of these plants from nonilluminated. I am curious how many days these plants would grow faster to
their final form because I think it would be a big difference.
Demostachya bipinnatas have more grown because I think that they generally
grow faster than date palms, so I gave the criteria that grass must grow to 40
cm and palms up to 30 cm.
Based on the experiment I conclude that in case of these plants, those plants
that have been illuminated grow faster and when they were illuminated more
than 3 seconds they growth slower but still faster than not illuminated plants.
20.02.2021
9
Bibliography
http://tropical.theferns.info/viewtropical.php?id=Des
mostachya+bipinnata
https://www.britannica.com/plant/date-palm
https://scienceforecastoa.com/Articles/JD-V1-E11007.pdf
http://justfunfacts.com/interesting-facts-aboutdates-and-date-palms/
https://www.motomed.com.pl/oferujemy/periodont
ologia-choroby-przyzebia/laser-biostymulacyjny/
https://atlas.roslin.pl/plant/9216
10