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Science Project

What is the Effect of Ozone on the Plant Growth of Radishes?

Researched by Vanessa R.



The purpose of this experiment was to determine the effect of ozone on the plant growth of radishes.

I became interested in this idea when I found out that ozone has been known to destroy crops.  Also I became interested when I discovered that a store carried a product called an ozonator that produces ozone to get rid of dirt and bacteria.

The information gained from this experiment may be used to warn farmers that the germination of plants was reduced when affected by ozone.


My hypothesis was that the ozone will effect the radishes grow by reducing it due to lack of carbon dioxide, and that the amount that the plant grows will be higher when set in its original air. Also when the plants are growing the plants in air will be farther ahead in healthy development than the plants in ozone.

I base my hypothesis on the fact that ìOne EPA estimate links ozone pollution to $2.7 billion worth of crop damage in 1995 alone î says Endzone partners in their article Effects of  Bad Ozone.


The constants in this study were:
 -The amount of ozone
 -The plant used (radish)
 -The amount of water every other day (10 ml)
 -The amount of light
 -The amount of soil in each cup (1 cup)
 -Size of cups (15 oz)

The manipulated variable was the air whether it was regular air or ozone.

The responding variable was the amount that the plant grew.

To measure the responding variable, each plant was spread out and measured from the top of the stem to the root.



20 radish seeds
10 styrofoam cups
1 ozonator
240 g soil
2 100 wt lamps
2 big clear plastic bags
1 roll of scotch tape
5-10 newspaper pages
1 ruler with metric measurement
1 light timer for ozonator


1. Gather all materials-
     -10 styrofoam cups with 3 punched holes in bottom of cup
     -10 cups of potting soil
     -2 lamps
     -water 10ml in the morning
     -1 roll of tape
     -2 big clear plastic bag
     -20 radish seeds
     -1 ozonator
     -1 light timer for ozonator

2. Pour 1 cup of potting soil into each styrofoam cup
3. Plant 2 radish seeds 13 cm deep in soil of each styrofoam cup
4. Pour 10ml of water in each of the 10 styrofoam cups and repeat every other day
5. Place 5 styrofoam cups inside plastic bag on the table so the plants donít fall over
6. Tape plastic bag on the ozonator, keeping 5 plants inside another plastic bag on the table
7. Turn on the ozonaight so that the plants get the same amount of light
10. Turn on the lamp to the highest setting
11. Repeat step 4 for 3 ½ weeks
12. At the end of 3 ½ tor
8. Turn on timer and set for ozonator to turn on every other 2 hours
9. Move plants to lweeks dump soil and plants on newspaper
13. Search for plants or seeds, carefully separate soil from roots
14. Measure plants from top of plant sprout to the tip of the plants in cm


The original purpose of this experiment was to determine whether plants grew better in ozone or air.

The results of the experiment were the plants in ozone germinated slower than the plants in air, and grew slower until the last week, when the plants in ozone started dying and shriveling. The  results of this experiment showed that the plants in ozone averaged only at 13.1 cm long while he plants in air averaged at 19.7 cm long.

See the table and graph below.


My hypothesis was the plants in ozone would grow less than the plants in air.

The results indicate that this hypothesis should be accepted. Plants in every trial showed the same negative effect of ozone.

Because of the results of this experiment, I wonder what would happen if we grew them in a CO2 environment.

If I were to conduct this project again I would probably start the trials earlier and conduct them longer to observe the extended growth. I would also run the entire experiment a second or third time to see if the results stay consistent.



The study of ozone indicates that it does destroy crops and this information will help inform many farmers of the dangers of ozone against crops so sometime in the future someone could find someway to protect plants and crops from the danger of ozone on plants.


The word ozone comes from the Greek word ozein, which means to smell. Ozone was a form of oxygen that was in the earthís atmosphere in small amounts. Usually oxygen has 2 molecules instead ozone has 3 formula was O3 and molecular weight of 47.998. Ozone boils at 119oc (-169.52oF) and melts at ñ192.5oc (-314.5oF) and has a gravity of 2.144. 

Pure ozone was a pale blue gas. Liquid ozone was a deep blue strongly magnetic liquid, which has a detectable odor. Ozone was used commercially in water purification processes and as a bleaching agent. 

Ozone was highly reactive with other compounds and when left to itís own devices doesnít linger long. Ozone can be good or bad depending where the ozone molecules are at that time. 

Ozone was produced naturally through photochemical and electric discharge reactions. Photochemical occurs when high radiation from the sun striking regular oxygen in the earthís upper atmosphere and changes some of it to ozone. Electric discharge reactions including lightning and sparks from motors can change oxygen into ozone. 


The ozonator was a machine that produces ozone to eat up dirt and bacteria. Ozone gets created when oxygen was exposed to high-energy Ultra Violate light. The ozonator was used mostly in hot tubs and spas to purify the water and to keep the spa or hot tub clean of bacteria growth.


Ozone has been known to have a damaging affect on crops. ìOne EPA estimates links ozone pollution to $2.5 billion worth of crop damage in 1995 aloneî says Endzone Partners in their article Effects of Bad Ozone.


In photosynthesis carbon dioxide was taken into the plant through the stomato. Photosynthesis occurs in sunlight. This was the process of photosynthesis: water was taken into the plant  through the roots then through the stem and to the leaves.

When a plant embryo begins to grow, itís cell carry on a process that uses stored food to produce energy. This process was called plant respiration, using complex food materials to supply the energy and embryo needs.


Crops are important and if we let ozone damage our crops then economy will drop big time. The reason of ozone destroying crops is due to photosynthesis.


Carter, Joseph, Goodman, Howard, Danny, Hunter, and Schelske, Leroy. Life Science. Lexington , Massachusetts: Ginn and Company, 1971. pp. 192-210

"Effects of Bad Ozone ." [Online] Available, November 18, 1998

"Good Ozone, Bad Ozone."  [Online] Available, November 18, 1998

"Ozone,î Encarta 98í. 1998

Stocker, Stephen H. "Ozone," The World Book Encyclopedia. 1995. vol. 14. pp. 894

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