Effects of Detergents on Plant Growth, Essay Example

Problem Statement

Germination is the process through which a plant or fungus emerges from a seed or spore and begins growth. Process of germination takes place naturally. However, the germination process is affected by numerous factors (detergents, weather and so on).  The experiment seeks o determine the effects of detergents on the germination. Lima beans and phosphorus (detergent) are used in the experiment. Typically, the research is focused on how detergent (variable) does or does not have an affect on the growth rate of plants.

Hypothesis

Growths of plants are negatively affected by being exposed to detergents (phosphorus in this case). The plants that are exposed to detergents grow at slower rates compared to the ones that are not exposed.

Literature Review

There are numerous factors that the germinating and plant growth depends. The type of sol, moisture content, and the pH are the major factors that determine the germination. It has found that when a high concentration of detergent are used to coat the leaves of a plant, the detergent removed the cell membrane of the leaves, killing them.  Even at lower concentrations, death of the leaves was likely because their protective wax is removed by the detergent. When a plant is sprayed by the detergent solution, the detergent goes straight down to the plant’s roots.  Therefore, the lipid membrane that surrounds the roots’ cells is killed, preventing the plan from absorbing water and nutrients. If there is enough evidence for both of these hypotheses, then there is apt demonstration that the independent variable was the cause of the results.  When detergent is present in the soil of plants, the growth is stunted, and when it is not present, the plants flourish. This experiment could be replicated in many ways, introducing phosphorus in various products and exposing various plants to them.  In trying to determine how significant a factor phosphorus in the water supply is for the growth of plants for example, experiments can be designed that observe rainfall amounts and how the phosphates in the water might stimulate the growth of water plants and how that may or may not increase the marine life in the area, such as fish.

Materials used:

• Cups (where soil was placed)
• Lima beans
• Water (To provide moisture for germination)
• Soil (medium for growth)
• Thermometer (for monitoring temperature)
• Measuring stick and tape measure (used to measure the growth of the plants)
• Seedlings were (maize, beans peas, papaw). Two of each kind was used and average found.
• Clock (for measuring time)

Experimental Design and procedure:

For the purposes of this experiment the independent variable will be; soil type, pH and moisture. The dependent variable will be the height of various seedlings and time. The lima beans will be measured before exposure to the detergents (initial height) and after 5 days continuously for 25 days. The same is done for the experiment and the control experiment.

Two set ups were used. The other was control experiment. The dependent variable was the plant height wile the independent was soil type, pH and moisture.

Experiment

The lima beans were planted in small cups in six inches of fertilizer-enriched pod soil, and two ounces of detergent was added to each cup.  The Lima beans were watered with de-ionized water every day and the growth monitored for four weeks. Beans were measured and results were recorded and averaged. The purpose of placing one of each per pot was to ensure accuracy of plant growth comparison. Seeds were planted in the middle of the pod soil (three inches from the topsoil layer). The plants were kept in a controlled climate during the course of the experiment inside a small greenhouse just adjacent to the house. In order to monitor the constant temperature, thermometer was used. This aided in keeping other conditions (Temperature, moisture) constant. Same soil was used and hence, soil pH was constant.

Control experiment

In the control experiment, similar conditions were used only that detergent (phosphorus was not used). Four control samples were used to validate the experiment and test each experimental variable twice to duplicate the results.  All the measurements were in millimeters to enhance accuracy. The average of the four was recorded after 1 week. The duration was for six weeks.

The chosen sequence used to collect quantitative data was by checking the plant growth weekly for any potential growth including the control and the four experimental plants.

Precautions taken

Gloves were worn when transferring materials and in measurement of liquids. This made sure that contamination was minimized.  Materials were carefully transferred using a pipette and volumetric flask to minimize chances of non-duplication of results.

Results

All the heights of the plants were recorder at each interval and averaged and then tabulated. On the tabulation of the results, the following table was made.

Experiment

The graph below was obtained when the average were plotted against time.

Control experiment

There is a gradual increase in the growth. The bending of the curve can be when the plant has past its exponential period.

Conclusions

In the experiment, there was a rapid rate of growth in the first five days. The rate therefore decreased thereafter. This indicates that the rates of growth were affected by the detergent (phosphorus). In the first 5 days the effects of detergent was not at the peak. The plants were slowly absorbing the detergent. This is not seen in the control experiment where the rate of growth is constant. The perfect straight line could not be obtained due to other factors that also affected the growths. The control showed nice growth for a period of 25 days, where the pollution or detergent exposed plants showed various minimal growths throughout the 25 days. The average of the growth is averaged through the tally recorded. Here is an example of the tally kept for 25 days. This study confirms the original hypothesis, namely that the application of detergents during the growth period of plants significantly decreased the rate of growth as compared with plans that were not exposed to detergents.

References

Cichetti, J. (2010). The effects of detergent on plant growth. Folio publishers. Pg 109-113.

Dark, B. (2007) Relative efficacy detergents. Retrieved on Jul 8^th, 2010 from  http://journals.cambridge.org/action/displayAbstract;jsessionid=101113365EC1BB25A32960151E82D4FA.tomcat1?fromPage=online&aid=763512

Dochinger, L. (1970). Effects of detergents on plants. Rasa publishers, pg 34-65.

Knud-Hansen, C.  (1994). Historical perspective of the phosphate detergent, working paper 94-54. Retrieved June 5, 2010. http://www.colorado.edu/conflict/full_text_search/AllCRCDocs/94-54.htm/

Mayers, C. (1998). What effects does detergent have on plants? Retrieved on 8^th Jul 2010, from www.madsci.org/posts/archives/nov98/912130550.Bt.r.html