Bio 211 A. Student The allelopathic effects of the Pinus Rigada on Raphanus Sativus A. Student October 22, 2015 Georgia Military College Introduction In a garden, Raphanus sativus were planted near other vegetables that were considered “companion plants”, but the R. sativus plantwas not exhibiting any real growth. Overhead Eastern pitch pine trees (Pinus Rigida) were growing and knowing that pine trees typically exhibit allelopathic tendencies, determining whether P. rigida was to blame or whether there was another contributing factor was important in getting to the root of the problem. To discover if the P. rigida were possibly inhibiting the growth, a study was done to determine if there was any connection between the stunted growth of the R. sativusand the P.rigida. The primary goal of this study was to gather and analyze data on the effects of the P. rigida on the growth of R. sativus. This was done to determine whether P. rigida exhibited allelopathic traits towards the seeds of R. sativus. The R. sativus is a cultigen, meaning it has been altered by humans and is the result of artificial selection. They belong to the Brassicaceae family, which includes turnips (Brassica rapa), cabbage and relatives (Brassica oleracea) and horseradish (Armoracia rusticana). The name Raphanus refers to the radishes ability to rapidly germinate and is derived from the greek language: ra, meaning quickly and phainomai, meaning to appear. (Plants & Fungi) Allelopathy is the secretion of chemical substances by plants that inhibit the growth of a competing species. (Allelopathy) A study was done on Pinus halepinsus and the possible allelopathic effects of its needles. In growth chambers, plastic pots consisting of 6(g), 8(g), and 12(g) of pine needle tissue and screened perlite were used to perform this study. Three different physiological stages of pine needles were collected from the P. halepinsus; fresh, senesced, and decaying. The pots containing the pine needle tissue were then seeded with tall fescue, Bermuda grass, or oat at 20, 20, and 3 seeds per pot. The needles tissue of the P. halepinsus in the perlite substrate reduced growth and development of the tall fescue and Bermuda grass. This suggests that toxic chemicals were excreted through the pine needle tissue. Growth inhibition was dependent on the type of pine and the amount incorporated into the pot. From the results, it was concluded that inhibitory compounds were within the pine needle tissue and were more apparent in fresh needles than senesced and decaying needles. (Nektarios, 2005) The Eastern P. rigidia is from the same family of trees as P. halepinsus called Pinaceae. Being from the same family, it is possible that they exhibit the same allelopathic traits. The inhibited growth of the R. sativus may be caused from possible allelopathic effects of the pine needles from the P. rigidia. If radish (R. sativus) seeds are exposed to extracts from the pitch pine tree (P. rigidi.

1. Bio 211 A. Student
The allelopathic effects of the Pinus Rigada on Raphanus
Sativus
A. Student
October 22, 2015
Georgia Military College
Introduction
In a garden, Raphanus sativus were planted near other
vegetables that were considered “companion plants”, but the R.
sativus plantwas not exhibiting any real growth. Overhead
Eastern pitch pine trees (Pinus Rigida) were growing and
knowing that pine trees typically exhibit allelopathic
tendencies, determining whether P. rigida was to blame or
whether there was another contributing factor was important in
getting to the root of the problem. To discover if the P. rigida
were possibly inhibiting the growth, a study was done to
determine if there was any connection between the stunted

2. growth of the R. sativusand the P.rigida. The primary goal of
this study was to gather and analyze data on the effects of the P.
rigida on the growth of R. sativus. This was done to determine
whether P. rigida exhibited allelopathic traits towards the seeds
of R. sativus.
The R. sativus is a cultigen, meaning it has been altered by
humans and is the result of artificial selection. They belong to
the Brassicaceae family, which includes turnips (Brassica rapa),
cabbage and relatives (Brassica oleracea) and horseradish
(Armoracia rusticana). The name Raphanus refers to the
radishes ability to rapidly germinate and is derived from the
greek language: ra, meaning quickly and phainomai, meaning to
appear. (Plants & Fungi)
Allelopathy is the secretion of chemical substances by plants
that inhibit the growth of a competing species. (Allelopathy) A
study was done on Pinus halepinsus and the possible
allelopathic effects of its needles. In growth chambers, plastic
pots consisting of 6(g), 8(g), and 12(g) of pine needle tissue and
screened perlite were used to perform this study. Three different
physiological stages of pine needles were collected from the P.
halepinsus; fresh, senesced, and decaying. The pots containing
the pine needle tissue were then seeded with tall fescue,
Bermuda grass, or oat at 20, 20, and 3 seeds per pot. The
needles tissue of the P. halepinsus in the perlite substrate
reduced growth and development of the tall fescue and Bermuda
grass. This suggests that toxic chemicals were excreted through
the pine needle tissue. Growth inhibition was dependent on the
type of pine and the amount incorporated into the pot. From the
results, it was concluded that inhibitory compounds were within
the pine needle tissue and were more apparent in fresh needles
than senesced and decaying needles. (Nektarios, 2005)
The Eastern P. rigidia is from the same family of trees as P.
halepinsus called Pinaceae. Being from the same family, it is
possible that they exhibit the same allelopathic traits. The
inhibited growth of the R. sativus may be caused from possible
allelopathic effects of the pine needles from the P. rigidia. If

3. radish (R. sativus) seeds are exposed to extracts from the pitch
pine tree (P. rigidia), then they will have less growth than the
seeds that are not exposed to extracts from the pitch pine tree
(P. rigidia).
Methods
Fresh pine needles from a Pinus rigida were collected and
rinsed with a 3% hydrogen peroxide solution to prevent any
microbial growth. They were then rinsed with water, cut into
small pieces (about ½ inch), and placed into a mason jar
containing water. More pine needle matter was placed into the
mason jar than water. The jar was labeled with the type of pine
needle, the name of the tree the needles came from, and the date
they were placed into the mason jar. The lid was placed on the
mason jar and the needles were stirred with a spoon several
times a day for three days, at the same time each day. Raphanus
sativus seeds were used to test for possible allelopathic traits of
the P. rigida needles. Five R. sativus seeds were first rinsed
with a 3% hydrogen peroxide solution to prevent any microbial
growth. They were then rinsed with water, folded up into
separate, plain paper towels, free of ink printed designs, along
with 1 tablespoon of the pine needles matter, and 1 tablespoon
of water mixture from each mason jar. An equal amount of
control seeds were folded up into separate paper towels, also
free of ink printed designs, with only water. Each paper towel
that enclosed a single seed with either pine needle matter or
water only, were then placed into separate plastic bags and
labeled control seed 1-5 or experimental seed 1-5 and then
placed into in a dark room for 10 days. After the 10 days had
passed, the bags and paper towels containing the seeds were
opened and the growth of the seeds were analyzed.
Results
The seed with the most growth was not exposed to the needles
of P. rigida. The other three of the five seeds exposed to the
needles had no growth at all, whereas all of the control seeds
had a significant amount of growth. These results indicate that
the pine tree, P. rigida, is allelopathic towards the R. sativus

4. seed.
Table 1: The amount of growth (cm) of each R. sativus seed
after 10 days
Seed number
Control growth (cm)
Experimental growth (cm)
1
7
0
2
15
9
3
16
0
4
14
6
5
13
0
Fig. 1: The growth (cm) of each R. sativus seed after ten days.
T-test: The mean growth of the control seeds was higher than
the growth of the experimental seeds. The difference between
means was significant (P= 0.003690 > 0.05) as seen in the t-test
below.
Discussion
S. sativus was used to determine whether or not P. rigida
exhibited allelopathic traits. All control seeds had more growth
than the experimental seeds, with the exception of control seed
number one as seen in table 1 & fig. 1 above. Although seed one
had the least amount of growth, it still had more growth than

5. four of the five experimental seeds, the exception being
experimental seed two as seen in table 1 & figure 1. Three of
the five experimental seeds experienced no growth as seen in
table 1 & figure 1. The average growth of the control seeds was
13 cm and the average growth of the experimental seeds was
10.2 cm. The mean growth of the control seeds was higher than
the growth of the experimental seeds. The difference between
means was significant (P= 0.003690 > 0.05) as seen in the t-test
below. These results indicate that the P. rigida has allelopathic
traits towards the R. sativus seeds. The lack of growth could
indeed be from P. rigida, as the plants in close proximity of R.
sativus were companion plants, but it is also possible that it
may have been from not having enough moisture in the soil or
the shade that the P. rigida was casting over R. sativus as they
need plenty of sun and moist, but not overly moist soil to grow.
Further testing could be done to rule out these possibilities.
These results also support the hypothesis.
LITERATURE CITED
Pine. (1). New York: Facts On File. Retrieved November
14, 2015, from
http://online.infobase.com/HRC/Search/Details/282938?q=pitch
pine
Pine. (1). New York: Facts On File. Retrieved November 14,
2015, from
http://online.infobase.com/HRC/Search/Details/282938?q=pitch
pine
Allelopathy. (2007). In Dictionary of Environmental Science,
Third Edition. New York: Facts On File. Retrieved November
14, 2015, from
http://online.infobase.com/HRC/Search/Details/278611?q=allelo
pathy
Allelopathy. (2007). In Dictionary of Environmental Science,

6. Third Edition. New York: Facts On File. Retrieved November
14, 2015, from
http://online.infobase.com/HRC/Search/Details/278611?q=allelo
pathy
Nektarios, P. A., Economou, G., & Avgoulas, C. (2005).
Allelopathic effects of Pinus halepensis needles on turfgrasses
and biosensor plants. Hortscience, 40(1), 246-250.
Journey North International Plant Study. Teacher Professional
Development and Teacher Resources by Annenberg. N. p., n.d.
Web. 28 November 2015.
"Plants & Fungi: Raphanus Sativus (radish) - Species Profile
from Kew." Royal Botanic Gardens, Kew - Home Page. N.p.,
n.d. Web. Feb. 27, 2016. http://www.kew.org/science-
conservation/plants-fungi/raphanus-sativus-radish
Growth of R. sativus seeds
Control Seed 1 Seed 2 Seed 3 Seed 4 Seed 5 7
15 16 14 13 Experimental Seed 1 Seed 2
Seed 3 Seed 4 Seed 5 0 9 0 6 0
Growth (cm)
t-test
Enter tails:2Enter 1 for a 1-tailed test. Enter 2 for a 2-tailed
test.

7. Enter type:21 = paired test; 2 = equal variances; 3 = unequal
variances
Enter data in yellow area below.
Enter only numbers. Values for time must be converted to either
minutes or seconds.
ControlExperimentalP =0.003690
70t =4.04888
159Degrees of Freedom =8.000000
160
146Mean (Group 1) =13
130Std. Deviation (Group 1) =3.53553
Mean Group 2) =3
Std. Deviation (Group 2) =4.24264
Once you complete the lab activity you will then complete the
lab report following the rubric below. This should be written
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correct lab assignment.
Lab Report Grading Rubric
CATEGORY
WHAT IS REQUIRED (Each section worth a total of 5 points
for a total of 40 points)
Cover Page
This should include the title of the lab, your name, due date,
and course title. This should be centered on the page.
Introduction/
Abstract
This section should include any background information. What
is being investigated, the purpose, and general information
about the process along with any expected results.
Methods/

8. Materials
The area should include what materials were utilized to perform
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Discussion/
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Literature Cited
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Appearance/

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The lab should be organized with the aforementioned sections.
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TOTAL POINTS
The above lab report should be written, formatted and cited
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Lab Inquiry Report Checklist
Bio 123/ General Guidelines for the Written Report
Read the “How to Write A Lab Report” document. Then, after
completing your experiment, Use this document to guide you in
writing the report. Once you are done, use the following to
doublecheck that you have included everything.
Introduction: this section is an overview of the background
information needed to understand the question you will pose for
your experiment. You should include enough facts and
explanation so that the question is understandable. You will
then provide a possible answer to this question in the form of a

10. hypothesis. Be sure to refer to the “How to Write a Hypothesis”
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What is the main question?
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Describe the experiment/research possibility
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What did you find out?

11. 1. Table of data
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3. Graph
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Hypothesis supported or rejected? Why?
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