Introduction: (Initial Observation)
Plants need water, light, air and nutrients to grow. Notice that we didn’t say food, we said nutrients. Plants make their own food. In order for the plants to survive and grow, they need small amount of nutrients. such nutrients are usually available in water and soil.
Sugar is a product that is made from plants. Have you heard about sugar cane? That is the plant that produces lot’s of sugar. Other plants produce sugar too, but in much lower amounts.
So what happens if we give sugar water to plant? Does it help the plant to grow more? or it will hurt the plant and disable it’s potential of making it’s own food. This is the subject of our project and we are going to perform some experiments to find out.
Attention: You may try this project on complete plants (plants with root) or on cut flowers.
Find out about sugar and plants. Read books, magazines or ask professionals who might know in order to learn about the effect of sugar on plants. Keep track of where you got your information from. Internet can be a good source of information about plants.
While you do your search, you will learn that nutrients for plants are also known as fertilizers. You may also learn about different types of fertilizers. Organic fertilizers are made from other plants and animals. Inorganic fertilizers are special chemicals or a combination of those chemicals produced in chemical factories.
Following are samples of information that you may find:
How to care for cut flowers?
First, before you put the flowers in a vase, cut the stems. Hold the stems underwater, and use a sharp knife to cut them on the diagonal. Don’t use dull scissors because they can crush the stem and prevent the flowers from soaking up as much water as they need. Make sure to remove all the leaves and thorns that will be underwater in the vase. Leaves under the water line can cause bacteria and algae to form.
Next, prepare the water. Most flowers prefer lukewarm water, although spring flowers (such as tulips, irises, and daffodils) survive best in ice-cold water. A floral preservative can help the flowers last longer. You can use a store-bought preservative or make your own. Some recipes mix lemon with a little bleach, while others recommend a teaspoon of sugar and a few drops of bleach. However, some experts advise against any home concoctions because they don’t provide the complex mixture of nutrients and preservatives that cut flowers need to survive.
Once your bouquet is in the vase, keep it out of direct sunlight and place it in a cool spot. Remove flowers as they wilt so they don’t contaminate the rest of the bouquet. Change the water at least every two or three days, if not daily. Make sure to add more preservative to the water every time, and you can re-cut the stems to allow the flowers to absorb more water.
What’s in those little packets the florists give you?
When a flower is cut from the mother plant, it is separated from its life support system. Just like an astronaut without a temporary life support system — it’s in trouble. Thus, nearly all commercial floral preservatives contain the basic components of the life support system for the cut flower: a biocide (explained below), an acidifier, and sugar.
Biocides are chemicals that kill the bacteria, yeasts and fungi that feed on the sap that seeps from the cut flower stem. It’s an amazing sequence of events: You cut a rose stem and place it in a vase of water. Bacteria start to grow, and within 3 hours, there are 30 million bacteria in the vase! These bacteria plug the tiny straw-tubes that conduct water to the flower. As a result, buds fail to open, necks weaken and bend, and leaves wilt. The acid helps water move up the stem more easily and the sugar acts as a flower food.
Put a penny in the vase: Wives’ tale or real solution?
If you don’t like to use chemicals to prolong the life of your cut flowers, there are “natural” alternatives. Some methods work better than others. Here’s one for you: does a penny and an aspirin tablet placed in the vase water really do any good? Some say the combination does keep flowers fresh longer. The theory is that the copper acts a fungicide and the aspirin makes the water more acidic. Here are more food + acid combinations:
- Add one part lemon-lime soda (not diet) to 3 parts water. Then to each quart of this solution, add 1/4 teaspoon bleach. Thereafter, add 1/4 teaspoon bleach after each 4 days of use.
- To 1 quart water add 2 tablespoons fresh lemon juice, 1 tablespoon sugar, and 1/2 teaspoon bleach.
- Add 2 ounces Listerine mouthwash per gallon of water. Listerine contains sucrose (food) and a bactericide. Listerine is acidic and is said help water move up the cut stem.
Nutrients essential for plant growth
What do you want to find out? Write a statement that describes what you want to do. Use your observations and questions to write the statement.
The purpose of this project is to determine the effect of sugar on plant growth.
When you think you know what variables may be involved, think about ways to change one at a time. If you change more than one at a time, you will not know what variable is causing your observation. Sometimes variables are linked and work together to cause something. At first, try to choose variables that you think act independently of each other.
Variable that may affect the plant growth in our project is the amount of sugar that we add to the water. In other words the effect of sugar water on plants varies based on the concentration of sugar in sugar water that we use.
Based on your gathered information, make an educated guess about what types of things affect the system you are working with. Identifying variables is necessary before you can make a hypothesis.
My hypothesis is that sugar will have no affect on plant growth. It may also harm the plant by attracting insects. My reason for this hypothesis is that sugar is not known as fertilizer and is not being sold in garden supplies.
Design an experiment to test each hypothesis. Make a step-by-step list of what you will do to answer each question. This list is called an experimental procedure. For an experiment to give answers you can trust, it must have a “control.” A control is an additional experimental trial or run. It is a separate experiment, done exactly like the others. The only difference is that no experimental variables are changed. A control is a neutral “reference point” for comparison that allows you to see what changing a variable does by comparing it to not changing anything. Dependable controls are sometimes very hard to develop. They can be the hardest part of a project. Without a control you cannot be sure that changing the variable causes your observations. A series of experiments that includes a control is called a “controlled experiment.”
In order to test the effect of sugar water on plant growth, we perform two different experiments. In one experiment we plant some seeds and test the sugar water on seedlings or young plants.
In the other experiment we use larger plants such as inexpensive houseplants to test the effect of sugar water.
You will need:
1. Three Styrofoam cups or small clay pots
2. dirt, potting soil etc.
3. 15 Bean seeds (5 for each cup or pot)
6. Journal (Note book)
- Fill the cups/pots with soil about half way. Plant the seeds. Cover with soil until the pots are about three-quarters full.
- Water and place all plants next to a window, where they can get enough light.
- Seeds will germinate in about 5 days.
- Get one cup of water and add one spoon full sugar and stir until sugar fully dissolves. Label it low sugar water.
- Get another cup of water and add two spoon full sugar and stir until sugar fully dissolves. Label it high sugar water.
- Get another cup of water with no sugar on that. Label it just water.
- When your young plant is ready (this takes about 2 to 4 weeks depending on weather, light and water) then you can start your final stage of your experiment as follows.
- Label your plants with “Control”, “low sugar” and “High sugar”. These labels represent the sugar water that you are going to use for that plant. You will use just water for control.
- Water your plants with water and sugar water in cups as needed
- Observe the changes on plants every day, measure the height of plant and record the results. In your observation look for any signs of growth or any signs of defect in plant.
- Repeat this if needed for about 15 days or until you see a change.
- Record the results in a table showing the height of each plant.
Plant height table:
|Start date||After 7 days||After 14 days||After 21 days|
|Low sugar plant|
|High sugar plant|
Make a graph:
You may make a bar graph to visually present your results. Make 3 vertical bars and name them “Control Plant”, “Low sugar plant”, and “High sugar plant”. The height of each bar must represent the plant growth in the length of your experiment (21 days).
- Find or purchase five same size green plants of any kind.
- Label your plants with “Control”, “low sugar” and “High sugar”. These labels represent the concentration sugar water that you are going to use for that plant. You will use water instead of sugar water for control.
- water the plants with water, low sugar water and high sugar water (prepare them as described in previous experiment)
- Observe the changes on plants every day and record the results.
- Repeat this if needed for up to 21 days.
- Record the results in a table showing the height of plant after certain number of days.
Take picture from your experiments and make drawings if needed. Use your plants and pictures as a part of your display.
Materials and Equipment:
List of material can be extracted fro the experiment section.
Results of Experiment (Observation):
Record the results of your experiment 1 in tables like this for each experiment:
|Start date||After 7 days||After 14 days||After 21 days|
|Low sugar plant|
|High sugar plant|
If you are using cut flowers, make daily observations.
No calculation is required.
Summary of Results:
Summarize what happened. This can be in the form of a table of processed numerical data, or graphs. It could also be a written statement of what occurred during experiments.
It is from calculations using recorded data that tables and graphs are made. Studying tables and graphs, we can see trends that tell us how different variables cause our observations. Based on these trends, we can draw conclusions about the system under study. These conclusions help us confirm or deny our original hypothesis. Often, mathematical equations can be made from graphs. These equations allow us to predict how a change will affect the system without the need to do additional experiments. Advanced levels of experimental science rely heavily on graphical and mathematical analysis of data. At this level, science becomes even more interesting and powerful.
Using the trends in your experimental data and your experimental observations, try to answer your original questions. Is your hypothesis correct? Now is the time to pull together what happened, and assess the experiments you did.
Related Questions & Answers:
What you have learned may allow you to answer other questions. Many questions are related. Several new questions may have occurred to you while doing experiments. You may now be able to understand or verify things that you discovered when gathering information for the project. Questions lead to more questions, which lead to additional hypothesis that need to be tested.
If you did not observe anything different than what happened with your control, the variable you changed may not affect the system you are investigating. If you did not observe a consistent, reproducible trend in your series of experimental runs there may be experimental errors affecting your results. The first thing to check is how you are making your measurements. Is the measurement method questionable or unreliable? Maybe you are reading a scale incorrectly, or maybe the measuring instrument is working erratically.
If you determine that experimental errors are influencing your results, carefully rethink the design of your experiments. Review each step of the procedure to find sources of potential errors. If possible, have a scientist review the procedure with you. Sometimes the designer of an experiment can miss the obvious.