Effect of different liquids during germination and
growth of Brassica nigra
Anisa Nakhuda
Candidate Number: 004380-0012
1/28/2016
Effect of different liquids during germination and growth of Brassica nigra
Background Information
In class we were learning about Germination and Post Germination of plants. We learnt about
photosynthesis and its significance in converting light energy into chemical energy. I learnt that the
main components of photosynthesis are sunlight, soil and water. The water in plants helps transfer
H2O (water) to CO2 (carbon dioxide). These CO2 molecules then produce carbohydrates, in which they
are "reduced, or receives electrons. The water becomes oxidized (loses electrons). Ultimately, oxygen
is produced along with carbohydrates” (Vidyasagar, 2015). Water also helps in the formation of
glucose (C6H12O6), which is the main source of food for plants. The main formula for plant
photosynthesis is:
6CO2 + 6H2O
Carbon dioxide + Water
Light
C6H12O6 + 6O2
Glucose + Oxygen
“A seed needs water to activate the enzymes that orchestrate the germination process.
Absorbed water also causes the seed to swell and soften which makes it possible for the plant to
break through” (Growanything.com). When water encounters the seed, the germination process
begins. Water softens the seed allowing the plant to break through and grow. “Plants utilise most of
the water absorbed from the soil for transpiration (95%). The rate of transpiration is dependent on
water availability within the plant (and soil) and on sufficient energy to vaporise water” (Clemson).
Water seems to be the main factor in plants growth and processes. However, besides the
formulation of glucose water doesn’t seem to change its properties or appearance. I would like to
replace the water and use something else to substitute it in order to observe whether the same
functions can still take place.
Water helps in transferring the “nutrients of the soil into the root system”
(Growanything.com). The food needed for the plant to grow and carry out functions is taken in due to
water. If water were not present, then the plant would not be able to obtain the needed nutrients.
I learnt that only water, soil and sunlight are needed for plant growth. One day I read about
farmers using different water based liquids such as coffee and aspirin for farming, and realised that
water may not be the only source of liquid needed by the plant for germination and post
germination.
Research Question
What are the effects of liquids (such as coffee, aspirin, milk and juice) other than water on the
germination and post-germination of Brassica nigra (black mustard) seeds?
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Aim
To investigate whether liquids other than water (milk, juice, coffee, aspirin) will affect the
germination and growth of Brassica nigra, commonly known as Black Mustard seeds.
Hypothesis
Coffee and Aspirin will germinate and post-germinate more successfully than the (carrot and
orange) juice and milk. This is because they contain more water, which is the main growth factor for
plants. Also, coffee contains caffeine that may help the plant grow faster. Aspirin has minerals and
nutrients that may help the plant not only grow faster but stronger. On the other hand, the juice and
milk may not be as successful although they do contain many nutrients and mineral such as calcium,
vitamins B and C and sugar.
Preliminary Experiment
A small packet of black mustard seeds was taken in order to test whether the seeds would
germinate or not in the different liquids (coffee, aspirin, milk and juice).
1. 10 seeds were planted in four different potting cups using gardening soil.
2. Each cup was watered with 15ml of a different liquid for two weeks outside.
3. After the two weeks, the number of seeds germinated was counted.
Results
Number of seeds germinated:
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Coffee = 6/10
Aspirin = 8/10
Milk = 5/10
Juice = 5/10
Total = 24/40
Percentage of Germination = 60%
The number of seeds that germinated was sufficient to continue with the experiment.
Variables
Independent: The types of liquid poured into the jars (milk, juice, coffee, and aspirin). Using a
measuring cup, 200ml of each liquid will be poured into the jars for 14 days. There will be 3 trials for
each liquid.
Dependent: Germination and Post Germination will occur based on the liquids. Germination will be
counted individually (per seedling), post germination will be measure with a 15cm ruler (±1mm).
Controlled/Constant:
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The type and amount of soil placed into each jar was consistent. A ruler was used to mark the
jars, indicating the amount of soil placed in each jar.
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200ml of each liquid placed in their respective jars for 14 days.
The jars were put in the same area (on a balcony) and made sure that each got an equal
amount of sunlight. The conditions experienced by the jars were consistent.
The seeds were placed at a 2cm depth within each jar.
Materials
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15×500ml plastic jars
15cm ruler (±1mm)
200ml × 14 days Carrot and Orange Juice
200ml × 14 days Full Fat Milk
200ml × 14 days Water
1tbsp × 14 days Espresso Instant Coffee
2 tablets × 14 days Aspirin
600 Brassica nigra seeds (40 in each pot ×15)
Soil
Screw Driver
Spoon
Measuring cup (±0.5ml)
Tablespoon
Safety and Risk Assessment
Gardening gloves were used while handling the soil in order to protect one’s self from any
harmful chemicals in the soil and insects that may reside in it. They were also used while dealing with
the screwdriver while making the holes at the bottom, in order to prevent and injury.
Procedure
1. Holes must be made at the bottom of the jars to let excess water drop out. A screwdriver is
used to make these holes. Two holes of an approximate circumference of 0.63cm were made
on the bottom of the jars.
2. Using the spoon, add 10cm amount of soil in the jars making sure there is a 2cm gap from the
top.
3. 15 jars are used, every 3 jars contained one type of liquid (there should be 3 jars for every
type of liquid, to use for trials). Sprinkle 40 seeds in every jar making sure they are spread
evenly.
4. In the remaining 2cm gap fill it with more soil.
5. Using the permanent marker, label the jars with the type of liquid that will be used.
6. Measure the milk, juice and water to 200ml using the measuring cup and pour inside the
labelled jar.
7. In 200ml of water, one tablespoon of coffee is dissolved and then poured into the jar.
8. For the aspirin, 2 tablets were used in every 200ml of water, dissolved thoroughly and poured
in the jar.
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9. Place the jars in an area with sufficient sunlight (i.e. balcony).
10. Water the plants when the soil dries out. You can test that by touching the soil.
11. Keep them for 14 days.
12. After 14 days, count the number of seeds that germinated and measure their length with a
ruler.
13. 3 Repeats were made, to ensure sufficient and reliable data.
Water was used as a control so other liquids could be compared to it.
Observations
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The milk started to curdle and gave a pungent smell that at times was unbearable. Although
some seeds germinated and started to grow, most of them died due to the curdled milk and
off-putting smell.
Around the milk jar many flies accumulated as well worms in the soil. In the 2 week period
there were worms found in all the jars however, the milk and the juice had the most and
biggest. This could be another factor that reduced chances of germination and growth.
Depending on the liquid type the soil would dry out quicker. This may be because these
liquids didn’t contain enough water to keep the soil moist. Milk was the driest, then juice,
aspirin, coffee and water was the moistest.
In the beginning the coffee grew surprisingly fast and very green, however, during the second
week the plants started to die out and turn a brown colour. This may be due to the over use
of coffee.
Seeds that germinated
All of the seeds were counted individually. Seeds that were cracked and plants that grew were
included. The raw data table can be found in Appendix (A).
Table #1
Seed Germination
Different types of
liquid (±0.5ml)
Water
Coffee
Aspirin
Milk
Juice
Trials
Seeds that
germinated /40
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
26
25
35
20
15
25
21
23
29
5
1
6
2
3
2
5
Average
Percentage ±2%
28.67
71.67
20
50
24.33
60.83
4
10
2.33
5.83
From the table of processed data we can see that (besides water) aspirin germinates the best
on average followed by coffee, milk and then juice. The following pie charts will help clearly identify
the percentage differences of seeds that germinated and those that did not, for every liquid.
Percentage of Seed Germination
Pie Chart #1
Pie Chart #2
Seed Germination with
WATER
Seed Germination with
COFFEE
Percentage of
seeds that
germinated
Percentage of
seeds that
germinated
Percentage of
seeds that DID
NOT germinate
Pecentage of
seeds that DID
NOT germinate
Pie Chart #4
Pie Chart #3
Seed Germination with
ASPIRIN
Seed Germination with
MILK
Percentage of
seeds that
germinated
Percentage of
seeds that
germinated
Pecentage of
seeds that DID
NOT germinate
Pecentage of
seeds that DID
NOT germinate
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Pie Chart #5
Seed Germination with
JUICE
Percentage of
seeds that
germinated
Pecentage of
seeds that DID
NOT germinate
Effects of different Liquids Post Germination
The liquid (water, coffee, aspirin, milk, juice) received by the Brassica Nigra affected its
growth post germination. The height of the seedling determined the effectiveness of the liquid used.
The higher the plant grew the more effective the liquid is on post germination. Raw data can be seen
in Appendix (A).
Table #2
Height of Seedling Post Germination
Different
types of
liquid
(±0.5ml)
Water
Coffee
Aspirin
Milk
juice
Trials
Trial seed
height on
average
/mm(±1mm)
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
Trial
Standard
Deviation
26.05
31.60
47.78
15.78
9.45
25.60
8.13
8.58
15.15
0.93
0.18
1.33
0.25
0.55
0.30
22.22
26.60
20.78
17.68
14.31
23.15
8.58
7.69
10.19
2.54
1.11
3.22
1.10
1.96
1.32
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Overall
Overall
height
Standard
average /mm Deviation
(±1mm)
35.14
23.20
16.94
18.38
10.62
8.82
0.81
2.29
0.37
1.46
While observing the table we can see that (besides water) Coffee has the highest average
seedling height followed by aspirin, milk and juice. This indicates that besides water, coffee produces
high seedling growth, which allows gardeners to use coffee based liquids besides plain water.
Although we can see that other liquids did produce some growth, they haven’t exceeded the way
coffee has. Although coffee produced better height averages, taking account the previous processed
data, aspirin had better germination results.
The bar graph below suggests that the difference between the liquids used in seedling growth
is not statistically significant. The error bars overlapped, which indicates that the type of liquid used
in plant growth may not be significant, supporting the hypothesis that any liquid can be used besides
water. However, the error bars do not overlap between the water and milk and juice. This shows that
a significant difference can be found between the three liquids. The variance given by the standard
deviation is large in the first two liquids (water and coffee) and then starts to get smaller by the third
(aspirin). By the last two (milk and juice) the variance given by the standard deviation is quite small.
To verify this, a T-test was carried out.
Bar Graph #1
Effect of different liquids on Brassica Nigra (Error Bars ±1
Standard Deviation)
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Average Seedling Height ±1mm
60
50
40
Water
Coffee
30
Aspirin
20
Milk
Juice
10
0
-10
Different types of liquids ±0.5ml
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Statistical Test
A t-test was carried out to find the significant difference between the means of coffee and
aspirin liquids. They showed a higher degree of uncertainty levels and overlapped each other more
than the others. A two-tailed test was carried out for the independent samples to find whether there
is significant difference between the effect of aspirin and coffee on the growth of seedling.
Null Hypothesis (H0): There is no significant difference between the effect of aspirin and coffee on
the growth of seedlings.
Alternative Hypothesis (H1): There is significant difference between effect of coffee and aspirin on
the growth of seedlings.
T-Test Formula:
Degrees of Freedom: n1 + n2 – 2 = 238
T-Value: 3.17
T Critical Value (p=0.05): 1.97
The t-value is greater than the critical t-value of 1.97 at p=0.05. This indicates that we accept
the alternative hypothesis, that there is significant difference between the effect of aspirin and
coffee on seedling growth post-germination.
Conclusion
In conclusion, my experiment supported my hypothesis. Coffee and Aspirin did perform better
than that of Milk and Juice compared to water. This was concluded by the amount of seeds
germinated and the height of seedlings post-germination (after 2 weeks). Although water is the main
factor of plant growth, this experiment allowed us to not only investigate but also reach the
conclusion that various types of liquids can be used besides water to grow plants. However, the
germination of seeds and the rate of post-germination growth varied from liquid to liquid.
In reference to the pie charts, we observe that water, coffee and aspirin produced the highest
amount of seed germination, compared to milk and juice. In the bar graphs there was an overlap
between coffee and aspirin, to which a t-test was conducted. The t-value produced was higher than
the critical value resulting in the acceptance of the alternative hypothesis, which stated that there is
significant difference between the effect of coffee and aspirin on the growth of seedlings.
Seeds are watered in order to soften them and stimulate plant growth. “Water activates the
germination cycle of the seed by causing the seed coat/hull to swell which in turn hydrates the cell of
the seed. Once hydrated, the hull is softened and will then allow the cell to expand and then break
through the protective outer layer of the seed” (Quora). For a seed to be hydrated water may not be
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the only source of liquid, any other can be used. This is because all liquids have a hydrating factor,
although they are not to the extent of water.
Although, the other liquids were able to stimulate plant growth, after a number of days the
rate of post-germination decreased. The plants started to grow slower after the 9th day, especially the
juice and milk. After the 12th day, some of the grown plants started to die out and by the 14 th day,
many of the plants dried and died. For the coffee and aspirin, this may have been due to over dosage
of the pills and coffee. For the milk, there was a lot of curdling of milk, which brought in insects that
destroyed the plant. The juice may have been too sweet and sticky causing growth stopping. Also,
another factor that may have contributed is the PH levels. Water normally balances PH levels
allowing for favourable conditions for germination. The other liquids used may not have been able to
neutralise the PH causing the plants to dry and die.
The pie charts (above) show the percentage of seeds that germinated per liquid (water,
coffee, aspirin, milk and juice), which helped validate my hypothesis stating which liquids were to
perform better and which were to perform the worst. However, my bar graphs showed a substantial
amount of overlapping which indicated that there might be no significance. When a T-Test was
conducted, the results showed that a significant difference could be found between the liquids.
Weaknesses and Improvements
The soil used in the experiment came from a local market. Although the same type and same
amount of soil was used in each pot of the experiment, there may have added impurities or
enhancers (such as vitamins and minerals), which could of affected the germination of seeds, by
either increasing them or reducing them. Some of the liquids used such as milk and juice reacted
quite drastically with the soil causing white worms to form in the pot. These worms meddled with the
seeds reducing germination and growth and killing some of the seedlings. If the experiment were to
be repeated, I would check the soil to make sure no worms have resided in it as well as provide
protection barriers for the seeds, in order to stop them from being eaten or dying off. One type of
barrier could be a toilet paper roll and place it around the seeds like a collar.
Brassica Nigra plants normally grow best in cool weather (6°C-27°C). When I started my
experiment it was still summer and it was very hot and humid (30°C-38°C). It wasn’t a suitable
environment to grow the plant in, this may have been why they were dying and did not germinate.
Next time, I would plant them around wintertime so the weather is cooler and chance for survival
increases. Because of the heat the soil was drying up quickly for some of the liquids (milk and juice), if
I were to do it again in winter the same problem may not occur.
The amount of liquid being placed in the jars differed because some plants were drying up
faster than others. Plants that stayed moist longer sometimes went a day without being watered.
This differentiation may have altered the results due to some being watered more than others are. If
the experiment were repeated I would try to bring more consistency with the amount of liquid and
the number of times the plants should be watered.
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Works Cited
Vidyasagar, By Aparna. "What Is Photosynthesis?" LiveScience. TechMedia Network, 31 July 2015. Web. 11
Dec. 2015.
"Why Do Plants Need Water?" GrowingAnything.com. N.p., n.d. Web. 15 Jan. 2016.
"Why Plants Need Water." Clemson Cooperative Extension. Clemson University, n.d. Web. 15 Jan. 2016.
"Why Do Seeds Need Wet Soil to Germinate and Grow into Big Trees?"Quora. N.p., n.d. Web. 24 Jan. 2016.
Appendix A (Raw Data Tables)
This is a small representation of the sample data.
Water Trial #1
Coffee Trial #1
±1mm)
±1mm)
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Aspirin Trial #1
Milk Trial #1
±1mm)
±1mm)
Juice Trial #1
±1mm)
Two additional trials were conducted (trials 2 and 3),
and are presented similarly to the tables of Trial 1.
However, due to the page limit I was not able to
present every raw data table.
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