Comparative Study of Lettuce Seed Germination in Different Media

The study aims to evaluate the effectiveness of three distinct media on the germination rate of lettuce seeds: distilled water, tomato juice, and a proprietary 'magic' growth solution. Statistical data is collected on metrics such as mean germination rates, standard deviation, range, and confidence levels for each medium. The distilled water medium shows varying germination with a mean of 79.25 and a high standard deviation, indicating significant variability in results. Tomato juice presents lower average germination but also demonstrates considerable variance, while the 'magic' growth solution delivers relatively stable and higher germination rates compared to the other two media. This comprehensive analysis seeks to identify which medium most effectively supports lettuce seed germination.

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Effects of Light and Substrate on Seed Germination
Name: Ahmed Ibrahim
Lab day and time: Tuesday, at 2 PM
Last date lab was performed: 11/14/2017
Lab partners: Mohammed Ibrahim, Robert Bohlken

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Effects of Light and Substrate on Seed Germination
Abstract
This experiment was conducted to determine the effects of different lighting and
substrates on the germination of seeds. The light was put into 6 (six) categories with a
combination of white light, dark, red light and far-red light. The substrates were also categorized
into three groups; distilled water, tomato sauce and Miracle growth. Seeds that were exposed to
different conditions and the germination rate recorded. It was found that seeds on distilled water
germinated better in general than those in tomato sauce and Miracle growth. Seed put on distilled
water and white light had an average of 79.25% germination. On the same category seeds on far-
red light, red light, and the into darkness had the highest rate of germination (94.02%). In
general, distilled water seed germination performed better with an overall mean of 47.34% than
Miracle growth which had an overall germination of 44.16. Finally, the different lighting
categories in the distilled water and Miracle growth media emerged significantly different in
germination rates. In contrast, seeds put in tomato sauce medium lighting categories did not
show any significant difference in germination.
RESULTS
The descriptive and inferential analysis in MS Excel will be provided in this section to
conclude whether there is a difference between the liquid media based on a various combination
of light wavelength.

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1 W L 2 W D 3 W
RL:D 4 W
FRL:D 5 W
RL:FRL:D 6 W
FRL:RL:D 7 T L 8 T D 9 T RL 10 T FRL 11 T
RL:FRL:D 12 T
FRL:RL:D 13 MG L 14 MG
D 15 MG
RL:D 16 MG
FRL:D 17 MG
RL:FRL:D 18 MG
FRL:RL:D
Distilled Water Tomato Sauce Miracle Growth
0.000
10.000
20.000
30.000
40.000
50.000
60.000
70.000
80.000
90.000
100.000
% Germination
Treatments
% germination
Figure 1: A bar graph overall means of germination.
Distilled water medium
Null hypothesis: Seed germination in different light treatments has no difference.
Table 1: Distilled water light treatments one-way ANOVA output
ANOVA
Source of Variation SS df MS F P-value F crit
Between Groups 106578 5 21315.503 61.427 0.000 2.368
Within Groups 20820.3 60 347.00534
Total 127398 65
The difference in germination percentage for the different light treatment (p-value
<0.001) is statistically significant at 95% confidence level.

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Tomato sauce medium
Null hypothesis: Seed germination in different light treatments has no difference.
Table 2: Tomato sauce medium light treatments one-way ANOVA output
ANOVA
Source of
Variation SS df MS F P-value F crit
Between Groups
15.0
8 5 3.015 0.719 0.612 2.368
Within Groups
251.
7 60 4.195
Total
266.
8 65
There is no significant difference of percentage germination (p-value = 0.612) of lettuce seeds on
different light treatments on Tomato sauce medium.
Miracle Growth medium
Null hypothesis: Seed germination in different light treatments has no difference.
Table 3: Miracle growth medium light treatments one-way ANOVA output
ANOVA
Source of
Variation SS df MS F
P-
value F crit

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Between Groups 101137.080 5 20227.416 38.406 0.000 2.368
Within Groups 31600.598 60 526.677
Total 132737.6785 65
The difference in germination between groups of different light treatments (p-value < 0.001) on
Miracle growth medium is statistically significant.
DISCUSSION
Germination of seeds requires a combination of various factors, which should be placed
in the best favourable conditions. These factors include a substrate and lighting effects, through
which the seed germinate if the combination meets the required criteria. The effect of
germination can be affected by the combination of different factors simultaneously. Bhardwaj
(2014) conducted a study to determine the effect of media on germination, a case study of
papaya (Carica papaya). Further studies have also been conducted to determine the influence of
excess or deficiency of these factors into the germination process (Baskin, Carol C., and Jerry M.
Baskin, 259). As a result, concrete information has been developed and outlined, hence
formulating guideline of the best practices of germination of lettuce seeds (Lactuca sativa).
Therefore, this study focuses on the effect of light and substrate on the germination
process of lettuce seeds (Lactuca sativa) which grows in a between 40°F and 80°F with an
optimum temperature of 68°F. The lettuce seeds also require a minimum of 3 – 4 hours of light
in a day. Light has been classified as white light, red light and far-red light, which are exposed to
different germination medium categories to observe the effect (King, John, 137). Lettuce seeds
require light wavelengths of 400 – 500nm. Also, the substrate has been classified as distilled

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water, Miracle grows and tomato juice to be used as media for the seed germination. Water is an
essential factor in triggering seed germination process. Without water or moisture, the seed
germination process will not start as anticipated. Tomato sauce provides moist environments but
due to acidity, the germination process is compromised. Miracle growth medium has several
macro and microorganisms which are essential for seed germination and they are usually
obtained from the soil. The differences in the germination process were recorded in lab sessions.
Another category of miracle grow was included, whereby the seed is exposed to micro and
macronutrients. The macronutrients include nitrogen, phosphorus, potassium, calcium,
magnesium, and Sulphur. The micronutrients include boron, chloride, copper, iron, manganese,
zinc and molybdenum (Baskin, Carol C., and Jerry M. Baskin). Therefore, the exposure of these
different liquid media to seeds was observed to check whether there are differences in
germination.
One-Way ANOVA:
The One-way ANOVA analysis output for the distilled water medium shows a p-value of
0.004 which is less than 0.05. We conclude that exposing seeds on distilled water medium with
different light wavelength affects their germination significantly. The percentages of germination
differ significantly showing that the light treatments in combination with distilled water have
significant effects on the process. Further, post hoc tests can be conducted to determine the
specific groups with significant differences in germination. Therefore we reject the Null that the
various light treatments do not have a significant difference in the percent germination of lettuce
seeds.
Tomato sauce is highly acidic (citric acid) and this is among the main factors which
inhibit seed germination (Baskin, Carol C., and Jerry M. Baskin). Therefore, the low percentages

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of germination in the seeds grown in tomato sauce were resulted by the fact that the medium
does not provide favourable conditions for the process.
Apart from water, oxygen and hydrogen which are needed for seed germination, macro
and micronutrients are needed for seedling growth. A medium containing most of these nutrients
might not necessarily favour adequately seed germination process because the nutrients are
important for the growth of the plants. Therefore, high rates of germination observed in the 13 th
to 18th plates were because the miracle germination medium highly favoured the process.
Finally, we can conclude that water was more significant in lettuce seed germination compared
to the miracle growth medium. This argument can be seen in figure 1 which visualizes the
overall average of germination for the three media.

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REFERENCES
Baskin, Carol C., and Jerry M. Baskin. Seeds: Ecology, Biogeography, and, Evolution of
Dormancy and Germination. Amsterdam, Elsevier Science, 2014.
Bhardwaj, L. R. "Effect of Growing Media on Seed Germination and Seedling Growth of Papaya
Cv. Red Lady." African Journal of Plant Science, vol 8, no. 4, 2014, pp. 178-184. Academic
Journals, doi:10.5897/ajps11.265.
King, John. Reaching For the Sun. Cambridge, Cambridge University Press, 2011.
Madu, Christian N. Statistics As Easy As 1, 2, 3 with Microsoft Excel for Windows. Fairfield, CT,
Chi Publishers, 2003.

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APPENDIX
Distilled water ANOVA: Single Factor
SUMMARY
Groups Count Sum Average Variance
1 W L 11 871.8 79.254545 1009.390727
2 W D 11 145.57 13.233636 121.2130455
3 W RL:D 11 971.33 88.302727 827.5820418
4 W FRL:D 11 47.59 4.3263636 23.75024545
5 W RL:FRL:D 11 54.09 4.9172727 11.97728182
6 W FRL:RL:D 11 1034.25 94.022727 88.11868182
ANOVA
Source of Variation SS df MS F P-value F crit
Between Groups 106578 5 21315.503 61.427 0.000 2.368
Within Groups 20820.3 60 347.00534
Total 127398 65
Tomato sauce ANOVA: Single Factor
SUMMARY
Groups Count Sum Average Variance
7 T L 11 6.1 0.554545455 3.382727273
8 T D 11 18 1.636363636 9.830545455
9 T RL 11 10.7 0.972727273 5.884181818
10 T FRL 11 1.7 0.154545455 0.262727273
11 T RL:FRL:D 11 7.44 0.676363636 2.280145455
12 T FRL:RL:D 11 13.44 1.221818182 3.531076364
ANOVA
Source of Variation SS df MS F P-value F crit
Between Groups 15.08 5 3.015 0.719 0.612 2.368
Within Groups 251.7 60 4.195

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Total 266.8 65
Miracle Growth Medium ANOVA: Single Factor
SUMMARY
Groups Count Sum Average Variance
13 MG L 11 748.3 68.02727273 1487.1422
14 MG D 11 151.43 13.76636364 713.07585
15 MG RL:D 11 1027.02 93.36545455 71.459127
16 MG FRL:D 11 22.3 2.027272727 7.1753618
17 MG RL:FRL:D 11 22.3 2.027272727 3.0385618
18 MG FRL:RL:D 11 943.2 85.74545455 878.16873
ANOVA
Source of Variation SS df MS F P-value F crit
Between Groups 101137.080 5 20227.416 38.406 0.000 2.368
Within Groups 31600.598 60 526.677
Total 132737.6785 65
Descriptive Statistics
Distilled Water Medium
1 W L 2 W D 3 W RL:D 4 W FRL:D 5 W RL:FRL:D 6 W FRL:RL:D
Mean 79.25 13.23 88.30 4.33 4.92 94.02
Standard Error 9.13 3.32 8.67 1.47 1.04 2.83
Median 96 11 97 3 3.6 98
Mode #N/A 0 98 0 9 100
Standard Deviation 30.29 11.01 28.77 4.87 3.46 9.39
Sample Variance 917.63 121.21 827.58 23.75 11.98 88.12
Range 897.50 28.00 98.13 14.29 10.34 30.30
Minimum 6.3 0 1.87 0 0 69.7
Maximum 100 28 100 14.29 10.34 100
Confidence 17.90 7.40 19.33 3.27 2.33 6.31

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Level(95.0%)
Tomato Medium
7 T L 8 T D 9 T RL 10 T FRL
11 T
RL:FRL:D
12 T
FRL:RL:D
Mean 0.55 1.64 0.97 0.15 0.68 1.22
Standard Error 0.55 0.95 0.73 0.15 0.46 0.57
Median 0 0 0 0 0 0
Mode 0 0 0 0 0 0
Standard Deviation 1.84 3.14 2.43 0.51 1.51 1.88
Sample Variance 3.38 9.83 5.88 0.26 2.28 3.53
Range 6.1 8.8 7.8 1.7 4 6
Minimum 0 0 0 0 0 0
Maximum 6.1 8.8 7.8 1.7 4 6
Confidence
Level(95.0%) 1.24 2.11 1.63 0.34 1.01 1.26
Magic Growth
13 MG
L
14 MG
D
15 MG
RL:D
16 MG
FRL:D
17 MG
RL:FRL:D
18 MG
FRL:RL:D
Mean 68.03 13.77 93.37 2.03 2.03 85.75
Standard Error 11.63 8.05 2.55 0.81 0.53 8.93
Median 84 4.3 95 1.2 2.8 97.3
Mode #N/A 0 100 0 0 100
Standard Deviation 38.56 26.70 8.45 2.68 1.74 29.63
Sample Variance
1487.1
4 713.08 71.46 7.18 3.04 878.17
Range 100 93 27 9 4.2 97.3
Minimum 0 0 73 0 0 2.7
Maximum 100 93 100 9 4.2 100
Confidence
Level(95.0%) 25.91 17.94 5.68 1.80 1.17 19.91