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By KevinP. (1998)

Contents:

Abstract:

The purpose of this experiment was to determine if adding different household substances to water would help plants grow taller. I became interested in this idea when looking though the science project ideas packet. The information gained from this experiment can be used by gardeners to have healthier gardens.

My hypothesis is that the Coca-Cola will help the plants the most. I base this hypothesis on information about plant nutrients I gained at the library.

I used four plant groups, including a control group, in my experiment. Each group contained a few seeds of Rudbeckia, Delphinium, and Oriental Poppy flowers. The constants in each group were:

- the amount and type of soil
- the amount of water
- the temperature
- the amount of light

The manipulated variable was what substance was added to the water. The control group received plain tap water and the experimental groups received water either with Coca-Cola, eggshell water, or S.O.S. water.

The responding variable was the height of the tallest plant in each cup. I would measure the height of each plant and record thetallest in each cup. I did this every Monday and Thursday.

The results after six weeks were:

For the Oriental Poppies, the Coca-Cola and S.O.S. pad had the tallest plants, alternating throughout the experiment. The Coca-Cola produced the overall tallest at 2.9 cm. The worst result was from the eggshells, that group produced the shortest plants and they died after the third week.

For the Rudbeckia, each of the experimental groups had shorter plants than the control group, but the S.O.S. pad produced the fastest growth for the first two weeks. The worst was the Coca-Cola because it had the shortest plants, but the eggshell group died after three weeks.

For the Delphinium, the Coca-Cola had the best results for the entire six weeks. The worst was the eggshells and the S.O.S. pad because they never started growing.

My results show that my hypothesis should be accepted for some plants and rejected for others. The Coca-Cola was helpful for the Oriental Poppies and Delphinium, but was bad for the Rudbeckia. If I were to perform this experiment again, I would use seedlings instead of seeds and irrigate with the modified water every third week or so.

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Purpose:

The purpose of this experiment was to determine if adding different household substances to water would help plants grow taller. I became interested in this topic when I was looking the science project topics packet. The information gained from my experiment can be used by gardeners to have healthier gardens.

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Hypothesis:

My hypothesis is that the Coca-Cola will help the plants grow the tallest. I base my hypothesis on plant nutrition facts I got at the library and the ingredients of the substances I used to water the plants.

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Experiment Design:

The constants of my experiment were:

- the amount of soil (200 mL)
- the amount of water (80 mL)
- the temperature
- the amount of light

The manipulated variable was the substance added to the water that the plants were watered with. There were three experimental groups and one control group. The control group received plain tap water while the experimental groups received:

- Eggshell Water - soak 4-5 eggshells in 2 L of water overnight.
- Coca-Cola Water - mix 250 mL (1 cup) of Coca-Cola in 2 L of water.
- S.O.S. Water - soak an S.O.S. pad in 2 L of water overnight.

The responding variable was the height of the tallest plant ineach cup. I would measure the height of each plant and record the tallest of each cup. I did this each Monday and Thursday.

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Materials:

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Procedures:

1. Carefully poke two holes with a diameter of about 1/2 cm. In the bottom of each cup. This is so that the water can drain and your plants will not drown.

2. Fill each cup with 200 mL of soil.

3. Place about 12 seeds of each type of plant in four cups each.

4. Label the cups with what kind of seeds is in it.

5. Water each plant cup with specified solution.

6. Record height of tallest plant in each cup.

7. Repeat step (5) once a week.

8. Repeat step (6) twice a week.

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Project Log:

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Background Report:

INTRODUCTION

This research report will explain why plants are important. It will also describe the structure of the green plant part-by-part, and explain why they are created the way they are. You will also be informed of what elements are needed by plants so that they can grow properly.

IMPORTANCE OF PLANTS

The energy we gain from food is first converted from sunlight into usable energy by green plants. The supply of oxygen in the Earth's atmosphere is a result of Photosynthesis by green plants. Fossil fuels come from plant material. Plants also create and modify environment conditions on which many animals and other plants depend.

Green plants form the base of the food chain and the beginning of the energy flow through an ecosystem. They are also the only important organisms able to assimilate inorganic elements and incorporate them into organic compounds in living tissues. The energy that is not used by the plant in carrying out its life processes goes into the production of biomass which canbe used by other organisms as a food source.

Edible, concentrated portions of various plants are used as a food source not only for the human populations of the world but also for livestock. The most important food plants are the grains of the grass family, particularly wheat, rice, corn, sorghum, and barley. In many tropical countries the higher-protein cereal grains do not grow well, and the basic foods are the more starchy root crops, such as yams and sweet potatoes. Plant foods contribute about 88 percent of the world's calories and about 80 percent of the proteins.

STRUCTURE OF PLANTS

A green plant's physiological processes are functions adapted to fulfilling its needs for energy, nutrients, water, reproduction, and dispersal. It accomplishes these by photosynthesis, assimilation, respiration, and growth. A plant's structural features, although obviously different in the various groups, are each specially adapted for carrying out these functions.

The functions of the root are to anchor the plant, absorb and transport nutrients and water, and sometimes to store food and serve in asexual reproduction. Adventitious roots, which do not arise either from the primary seed roots or as branches of later-developed roots, often appear at the nodes, or junctions ofthe stem.

Root systems may consist of one major root or of a excessive mass of similar-sized branches. Penetration into the soil is accomplished by cell division and by the lengthening of cells just behind the tip of the root. A protective cap covers the tip. Just behind the elongated region of the root are the root hairs, which are small projections of the epidermal cells. The tremendous combined surface area of the abundant root hairs is responsible for absorption of water and minerals. Once absorbed, they pass through the cortex, or root wall, into the center of the root. Here these substances are carried upward through the tracheids and vessels of the xylem.

Functions of the stem are to produce and support new leaves, branches, and flowers and place them where they can be of most use. It also transports materials to and from the roots. Frequently, stems serve to store food, carry on photosynthesis, and reproduce new plants.

Support is provided by various thick-walled cells found in the xylem or in strands outside the xylem. In herbaceous stems, internal water pressure is also important.

Water and minerals are transported in the xylem and manufactured food is transported in the phloem. In monocot stems the conducting tissues occur in separated, usually scattered, bundles, whereas in dicot stems the vascular tissues are arranged in a ring, with the primary xylem on the inside, the primary phloem on the outside, and a layer of dividing cells, called the vascular cambium, between them. The term wood in its commercial sense refers to secondary xylem. Secondary xylem is produced by the vascular cambium inward toward the center of the stem between itself and the primary xylem, increasing the thickness of the stem. The yearly production of secondary xylem usually forms a ring around that of the previous year, and these rings can be used to determine the age of the tree. In a similar manner secondary phloem is produced by the vascular cambium outward toward the surface of the stem between itself and the primary phloem; this, too, contributes to the thickness of the stem.

The leaves intercept light, exchange gases, and provide a site for photosynthesis. Some leaves also store food and water, provide support, or form new plants.

A flat, broad, thin structure gives more surface area for light interception and penetration. Where high light intensities are harmful, leaves may reduce the effects of the light by orientating themselves vertically, by becoming thickened or covered with hairs, or by having a highly reflective surface.

Intake of carbon dioxide and release of oxygen occurs through the stomata, small pores in the leaf's surface. The stomata are mostly on the lower surface and are able to close at midday. The cells within the leaf may be formed into two layers, the upper layer, tightly packed with elongated palisade cells, and the lower layer, loosely packed with spongy tissue. Photosynthesis occurs mostly in the palisade cells.

The flower is the sexual reproduction unit that functions to produce and house gametes (sex cells) and to attract pollinators such as bees. The stalk portion (pedicel) of the flower ends in an enlargement, called the receptacle, from which arise the sepals, petals, stamens (male units), and carpels (female units). Sepals are often green, being the least evolutionarily modified from leaves. The petals are usually larger and colorful, serving to attract the pollinator. Stamens produce and house the pollen, which contains the male gametes. Carpels produce and enclose the ovules, which contain the female gametes. A carpel may develop into a simple pistil, or several carpels may fuse to form a compound pistil. Whether simple or compound, a pistil typically consists of an enlarged ovary, from which arises an elongated style topped by a pollen-receiving stigma. Plants use many agents for transporting pollen from one flower to another, including wind, insects, birds, and bats.

As the fertilized egg within the ovule develops into an embryo, the ovule walls develop into a seed coat, forming the ovule into a seed. The seed serves as the unit of dispersal for the new plant. It also provides some protection from injury and drying and some nourishment for the young plant until it can make its own food.

NUTRIENTS PLANTS NEED

The three main nutrients that plants require are nitrogen, to help with photosynthesis; phosphorus, which is needed for the development of roots, flowers, seeds, and fruits; and potassium for healthy stems and disease resistance. Along with these, plants also need carbon, hydrogen, oxygen, sulfur, calcium, magnesium, and iron in small amounts. In even smaller amounts are needed boron, copper, manganese, and zinc. Plants also take in silicone, chlorine, and sodium, but these are not known to be needed for plants to be healthy. There is also a group of elements that are not known to be even remotely needed including, aluminum, arsenic, lead, barium, mercury, bromine, tin, cobalt, gold, nickel, and selenium.

SUMMARY

This report has explained about the importance of plants and described the anatomy of each part of the green plant and explained why they are built the way they are. It also informed you of what elements are needed by plants so that they can grow properly.

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Results:

The original purpose of this experiment was to determine if adding different household substances to water would help plants grow taller. The results were that adding Coca-Cola helped more than the other substances I used. The eggshells seemed to slow the growth and make the plants die off quicker. Below is a graph of the average plant growth.

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Conclusions, Analysis, and Reflections:

My hypothesis is that the Coca-Cola will help the plants the most. I base this hypothesis on information about plant nutrients I gained at the library. My results show that my hypothesis should be accepted for some plants and reject for others. The Coca-Cola was helpful for the Oriental Poppies and Delphinium, but was bad for the Rudbeckia.

Because of the results of this experiment, I wonder if too much modified water is bad for the plants. If I were to perform this experiment again, I would use seedlings instead of seeds and irrigate with the modified water every third watering or so.

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Bibliography:

Foster, Catharine O., Organic Flower Gardening, Emmaus, PA, Roale Press, Inc., 1975.

Mackey, Betty, et al, The Gardener's Home Companion, NewYork, NY, Macmillan Publishing Company, 1991.

Foster, Catharine O., Building Healthy Gardens, New York, NY, The Alpine Press, 1989.

"Plant", Grolier Multimedia Encyclopedia, 1995

"Plant", Microsoft Bookshelf, 1994

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Appendix:
Glossery

Adventitious roots - roots which do not arise either from the primary seed roots or as branches of later-developed roots.

Assimilate - To consume and incorporate nutrients into the body after digestion.

Calyx - The sepals of a flower considered as a group.

Cortex - root wall.

Dicot - A flowering plant with two embryonic seed leaves orcotyledons that usually appear at germination.

Herbaceous - Relating to or characteristic of an herb as distinguished from a woody plant.

Monocot - A flowering plant with one embryonic seed leave or cotyledon that usually appear at germination.

Ovule - A minute structure in seed plants, containing the embryo sac and surrounded by the nucellus, that develops into a seed after fertilization.

Pales - A stake or pointed stick; a picket.

Palisade - A fence of pales forming a defense barrier or fortification.

Phloem - The food-conducting tissue of vascular plants, consisting of sieve tubes, fibers, parenchyma, and sclereids.

Sepals - One of the separate, usually green parts forming the calyx of a flower.

Stele - center of the root; also vascular cylinder.

Stomata - small pores in the leaf surface.

Taproot - major root of a root system.

Tracheid - a long tubular pitted cell that is peculiar to xylem.

Turgor - internal water pressure.

Vascular Cylinder - center of the root; also stele.

Xylem - the supporting and water-conducting tissue of vascular plants, consisting primarily of tracheids and vessels.

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