Swan(sea) Song – personal research during my six years at Swansea ... and bey...
Paper exp 2 bot #1
1. Abstract
Transpiration is one of the most common processes of temperature regulation. The rate
of transpiration depends on several weather factors, such as wind and humidity, as well as
structural factors. Previous studies have shown that increase of air movement result in increase
of transpiration by the plant. This study aims to prove if wind affects the transpiration of
Centaurea cyanus plant by increasing the rate of transpiration. Using a potometer, the range of
transpiration was measured every three minutes for a total of thirty minutes, resulting in an
increased transpiration rate for the plant that had an air current applied to it. In conclusion, wind
is indeed a contributing factor in the determination of transpiration rates, effectively increasing
them in the sample plants.
Introduction: effective against inflammation in the region
of the eyes and conjunctivitis. The seed have
Centaurea cyanus, more commonly also been used as gentle laxatives for
known as “Bachelor’s button” or children and as a stimulant for enhancing
“Cornflower”, is annual flowering plant digestion and to support some internal
belonging to the Asteraceae family. organs such as the liver.
Because C.cyanus can be easily cultivated in
a wide variety of soils (preferably in well- Plant transpiration is the release of
drained soils) and can tolerate extremely water vapor to the atmosphere through the
exposure to sun light this herb can be easily stomata by the evaporation of water located
grown in areas such as North America, in the intracellular spaces inside the plant.
Europe, Brazil, and Asia. Its leaves are long Approximately 10% of all moist found in
and they emerge alternately on the stem, the atmosphere is released by transpiration;
which can grow up to a height of 16-35 however, many external factors contribute to
inches and is usually very thin and ramified, the rate of transpiration in organisms.
with flowers (usually containing a wide Several factors, such as temperature,
range of colors such as blue, pink or white) humidity, soil moisture, and air movement
growing at their tips. The flowers are contribute to how much water vapor is
hermaphrodites, meaning they have male released from the organism. Humidity and
and female organs, and are pollinated with air movement have a close relationship in
the help of other organisms such as insects. terms of affecting the rate of transpiration in
plants; as water inside the cell evaporates, it
C. cyanus has a wide range of saturates the air surrounding the leaf with
medical applications. In French herbal water vapor, increasing the humidity around
medicine it is used for the eye treatments in the leaf, which in turn decreases the rate of
the form of poultices or eyewashes; the transpiration. However, if wind is present,
gentle antiseptic and astringent properties of blowing away the humid air and replacing it
cornflower make the herb especially with drier air, water evaporation inside the
2. plant will continue, and therefore, the rate of cyanus, a common grassland plant, when a
transpiration in the plant will rise. In this air current is applied.
experiment the rate of transpiration of C.
syringe to refill the pipettes if necessary; and
a fan to produce the air current. First the
Materials and Methods stem was cut with a razor blade in order to
The experiment was based upon fit the plant in the connector tube. Then,
seeing how the rate of transpiration of C. with a syringe, the pipette was filled with
cyanus was affected when an air current is water until the meniscus read 0.9mL
applied. A potometer, or transpirometer approximately. The plant stems were then
shown in fig. 1, was utilized, which is a placed in the connector tubes and only one
device used for measuring the rate of water had a fan placed directly in front of it; the
uptake of a leafy shoot. . The set-up other served as a control group. Every three
consisted of a 1.0 mL pipette with water; a minutes, for a period of thirty minutes, the
connector tube to transport the water; amount of water in the 1mL pipette was
clamps to hold the pipette and the plant in measured to see the rate of water uptake of
place; two lamps to induce photosynthesis; a each stem cutting, which is directly
proportional to their rate of transpiration.
Results
At first large difference between the two
plants were not shown, but after several
minutes the plant with the fan placed in front
of it exceled in showing more transpiration
than the control. According to the
observations made during the experiment
Plant B, containing the variable (wind), as
shown in figure 1, show a wide range of
transpiration while the control shows not
transpiration at all. From the minute 6, table
1, the plant with the fan placed in front of it
excelled in showing more transpiration than
the control. The amount of water absorbed,
and therefore, the rate of absorption of
Centaurea cyanus plant increased by a
Fig.1: Potometer set-up
factor of approximately 68 when exposed to
wind.
3. Time (minutes) Control (without breeze) Experimental (with breeze)
0 0.8975 0.8460
3 0.8950 0.8445
6 0.8973 0.8440
9 0.8970 0.7985
12 0.8970 0.7875
15 0.8970 0.7968
18 0.8968 0.7960
21 0.8965 0.7948
24 0.8965 0.7935
27 0.8965 0.7925
30 0.8960 0.7440
Table 1: Average values of absorbed water
Figure 1: Average values of absorbed water
Average values of absobed water
0.95
Pipet measuments (mL)
0.9
0.85
0.8
0.75
0.7
0 3 6 9 12 15 18 21 24 27 30
Time (minutes)
Control (without breeze) Experimental (with breeze)
*Pipet measurements are inversely proportional to the amount of water transpired.
4. Average amount of absorbed wate
Experimental: 0.1020mL
Control:0.0015mL
Average rate of absorption:
Experimental: 0.00340mL/min
Control: 0.00005mL/min
Increase Factor: 68
Discussion
The data in the Table 1 demonstrated that during the first few minutes a large difference
between the two plants wasn’t evident, but after six minutes the experimental plant absorbed
more quantities of water that the control plant. This is due to the fact that wind carries away the
humid air over the plant’s surface, more specifically, the leaves. This, in turn increases the rate of
water evaporation from the intercellular spaces inside the leaf, which increases the rate of
transpiration. This is evident by the amount of water that the experimental plant absorbed; the
plant was losing water through evaporation. These results are consistent with the information
presented in the class textbook that states that this phenomenon is due to the fact that when there
is wind present, the water vapor near the surface of the leaf is blown away, affecting the vapor
pressure difference across the surface and accelerating the rate of evaporation of water from the
intercellular spaces in the leaf, which in turn, increases the rate of transpiration (Raven et al.,
2005). The results also coincide with recent investigations that state that increase air circulation
increase the rate of transpiration (Thongba et al., 2010). In conclusion, the hypothesis of this
investigation was proven to be true because the environmental factor, wind, did in fact increase
the rate of transpiration of the Centaurea cyanus plant. Further investigations might be able to
provide an insight into more adequate techniques for plant care.
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