NEWTON COLLEGE
Carissa Lukac
SCIENCE DEPARTMENT
IB BIOLOGY
ROOTING EXPERIMENT
Exploration:
Being exposed to many hazardous elements in nature and in their environment, Plants are
exposed to many hazardous elements that prohibit their growth or inhibit their reproduction.
In higher plants, there are mainly two methods of reproduction-sexual reproduction that
involves the formation of gametes where seeds are used for propagation and asexual
reproduction, in which there the vegetative parts are used for propagation. Nurseries have
developed a simple yet highly effective method of plant reproduction called "Cutting",
propagation by stem cuttings has become the most commonly used method to propagate
many woody ornamental plants. Stem cutting of shrubs is easier to root than of trees. Since
greenhouse are not needed, successful propagation can be obtained in any context, with the
condition of maintaining high humidity around the cutting. This process has enabled mass
production derived from a single source plant, as it is able to produce many offspring from
excess branches that would most likely be be pruned for aesthetics. Many methods of cutting
are used to propagate plants, they vary from location of the cut on the stem and the shape of
cut. Numerous types of plants can be propagated using cutting but for this experiment the
mentha spicata plant will be used along with the stem cutting method. The reason plants can
take root from cuttings is that each cell in the plant has all the genetic information necessary
to produce a complete plant. When a cutting is taken the connection between the stem and the
root is removed. The changes in growth patterns are regulated by plant hormones produced in
the leaves, stems and roots of the plant. Once a cutting is taken, the plant hormones no longer
travel back and forth between the roots and the stem. The change signals the plant to first heal
the wound, and then replace the missing roots. According to the Oregon State University,
nitrogenous compound in the form of ammonium or nitrate, are used in fertilizers to enhance
plant growth. The purpose of this experiment is to determine if coffee grounds in soil is a
good growing media for the stem cuttings to grow.
Research Question:
To what extent do nitrogen compounds found in coffee work as a medium for rooting to
occur?
Hypothesis:
As Coffee grounds presernt a high amount of nitrogen, it is expected for the mentha spicata
cuttings cultivated in a medium with soil and coffee to grow roots.
Variables:
Independent:
o Use of coffee on soil
o Growth of roots
Dependent:
o Number of roots
Controlled:
o Same plant leaf
o Stem size
o Amount of soil on each medium (BUSCAR CUANTO)
o Amount of coffee on each medium (BUSCAR CUANTO)
o Watering of plant
o Time period
Method:
1. Select a different stems from the mentha spicata plant
2. Cut the stem in 6 different parts each 5 cm of size
3. Create a hole on the base of a plastic cup
4. Mix the soil with ……. Amount of ground coffee
5. Repeat step 3-4 for other 5 cups
6. Add one stem cutting to each plastic cup
7. Water with 10ml
8. Keep results indoors
9. Water each stem every 2-3 days
10. Do not take the stems out from the soil until time chosen to stop the experiment is
accomplished
Materials:
1. 6 stem cutting from mentha spicata
2. 20 ml measuring cylinder
3. Water
4. Plastic cups
5. Soil
6. Ground coffee
How are the variables controlled?
Same plant specie stem: When using the plant’s stem that will be cutted for rooting,
choose the stems from the same specie so that there are no conffussion between
capacities of certain plants that can propagate through stem cutting
Size of stem: Each stem cutting will be of 5cm
Watering of plant: The plants will be watered in intervals of 2 to 3 days
Amount of coffee: … will be used in the solid medium in which the plant will grow in
Amount of soil:.... Will be used in the solid medium in which the plant will grow in
Time period: This experiment will span a two-week time period to determine in which
growing media-sphagnum peat, sand, vermiculite, potting soil-cuttings root the best
in.
Analysis:
Table 1: Quantitative Data
Number of the plant Number of roots
1 0
2 0
3 0
4 0
5 0
6 0
Table 2: Qualitative Data:
Number of Observations
the plant
1 Soil was completely dry, no roots grew from stem, when the stem was put out of the
soil, its texture was hard and it breaked easily while its soil was not mixed with the
coffee as the coffe came out first and then the soil when disposing it.
2 Soil was completely dry, no roots grew from stem, rock like formations were found in
the soil as if it has endured itself. The stem was broken.
3 Soil was completely dry, no roots grew from stem, when the stem was put out of the
soil, its texture was hard and it breaked easily.
4 Soil was completely dry, no roots grew from stem, the soil and the coffee were not
mixed correctly
5 Soil was completely dry, no roots grew from stem, a worm was found in the medium
6 Soil was completely dry, no roots grew from stem.
Photo 1: All results Photo 2: Test 1
Photo 3: Test 2 Photo 4: Test 3
Photo 5: Test 4 Photo 6: Test 5
Photo 7: Test 6
Expected results:
Uncertainty of the experiment:
A systematic error may have occurred during the experiment, which proves that the method
taken was not as reliable as it should had been. Neither of the roots expected to grow were
visible, therefore a speciofic requirement for the species selected (mentha spicata) such as
temperature, pH or moisture of the medium.
Interpretation from results:
No conclusion can be obtained from the results obtained, however it can be compared to the
standard results from other previous experiments done by other studies we can conclude that
the conditions for the specie to grow were not fully aplied.
What are the limitations and weaknesses of this experiment and how could it be improved?
One of the limitations of the experiment is that we only analysed the growth of the roots under
one circumstance without calculating a change between other independent variables, for
example we could have compared the growth of roots on a medium with caffeine in an outdoor
vs an indoor exposure. This would have provided broader results to be analysed and compared.
In order to have a concrete result regarding the growth of the roots fom the sten cutting, we
should have expanded the time period of wait, this way we would have followed the species
growth requirements. The watering should have been measured correctly to provide a trustful
measurement of the plant’s humidity without having plants which received a higher amount of
water than others.
Safety Precautions:
Mentha spicata may produce redness or itchiness on the skin, if the subject believes he may be
suceptible to this because of allergies) it is recommended to wear gloves.
Evaluation:
Conclusion from results:
As seen in table 2, qualitative results show the susceptability of spearrmint to rust and
mealybug or aphids. It has been proven by previous studies that nitrogen and caffeine are an
effective fertilizers for plants to grow in faster, therefore it should be concluded that the
experiment did not work since the methodology applied was not the correct one.
Corroboration of conclusion with botanic information of the species used:
Mentha Spicata is a plant with an aggressive spreading of roots, they require a space to let them
roam. The cutting should have been 10cm and soaked in water before put in the soil for the
stem to be turgid before planting it. This species requires a contact miticde such as Safer’s
insecticidal soap to prevent pest infestation. The medium in which it shouild grow in should be
moist most of the time with a watering interval of 2-3 days, between each interval, before
watering the soil should be as dry as possible. Roots should begin to show in between 3 to 4
weeks.
Corroboration of conclusion from other scientific research:
Cooffe……….
Bibliography:
https://www.youtube.com/watch?v=86A7U4LOCv8
https://academicjournals.org/journal/AJAR/article-full-text-pdf/B34189955623
http://ib.bioninja.com.au/standard-level/topic-3-genetics/35-genetic-modification-and/stem-
cuttings.html
