• Topics: 4-H Youth Development | 4-H Gardening | Stephens, James M

Beginning Gardening Unit 1: Plant Science Experiments¹

This gardening project area is designed for you 4-H members who do not have the time and space necessary to grow a vegetable garden. By taking it, you will study some important things about probably the most important life on earth–living plants. They are the only living things that can make their own food. All other life depends on them. You will learn how plants grow from seed and how these plants are affected by their surroundings. And, you will learn the ways of a scientist–how he carries out his tests and experiments. Don't be surprised if you even learn some new, scientific words. In short, you will become a plant scientist for a brief time.

Requirements of the Project Area

There are five easy experiments outlined for you to select from. You must complete at least three of them, although you may do them all if you desire.

By following the directions, you should have no trouble completing each experiment. The materials needed are simple and easy to find. It is possible to run all of them at the same time.

For each experiment, you must write a report. It is a good idea to keep track of the experiments in a notebook. In this way, you will have all the needed information when you are ready to write your report. For your report use the cut-out pages in the back of this booklet.

Other Beginning Gardening Project Areas

Figure 1. 

You can learn about vegetables and even grow your own by taking the Beginning Gardening Project, though your yard may not be large enough for a garden.

Plant Science Experiments is one of four areas you may select in the Beginning Gardening (Unit I) project. The four areas are: (1) Plant Science Experiments, (2) Growing Vegetables in Containers, (3) Vegetable Identification Workbook, and (4) Vegetable Gardening. There is a separate booklet for each area.

You may choose at least one of the four areas. If you complete one area one year, you may wish to do another area the next year. You should be 10 to 12 years old to do this project.

EXPERIMENT 1

Getting Seeds to Germinate

A seed contains a tiny plant called an embryo. It rests in the seed until it is placed in the right surroundings for it to germinate (sprout). For it to awaken, it must have water (moisture), oxygen, and the proper temperature. Some seeds, not many, need light also.

The right temperature is different for different groups of seeds. Warm season plants such as melons germinate best at 90°F. while cool season crops such as lettuce germinate best at 75°F. Most of these will not germinate at all if the temperature becomes too hot or too cold.

In this experiment, you are going to see how seeds germinate. You will also see how temperature changes the sprouting time of several kinds of seeds.

Figure 2. 

Materials needed - Drinking glasses or jars, paper towels, vegetable seed, and saucers.

Procedure - First, soak overnight some squash, melon, or cucumber seeds and some lettuce, beet, or radish seeds in the saucers. Also, you may try some other seeds that you have on hand.

Then, find six drinking glasses or jars. Line the inside of each of them with a paper towel. Cut it off evenly at the top of the glass, and be sure the paper fits evenly against the bottom.

Figure 3. 

Put about one inch of water in the bottom of three of the glasses and watch the paper soak up the water. Leave the other three dry. They are your "controls." This way you will have an untreated group to compare your treated seeds with

Now, put a couple of each kind of seed that you soaked overnight between the moist paper and the sides of each glass. Do not put them down in the water on the bottom.

Then, place two containers (one with water and one without water) in a warm room such as the kitchen; place two containers (again one with and the other without water) in a medium warm room such as a bedroom; and place the other two in the refrigerator.

Figure 4. 

Look at the seeds every day. Keep the bottom of the glass covered with water. This is a good method to watch seeds sprout. Keep notes on what you see so you can write your report. Do all the seeds sprout at the same time? 'What starts to grow first, the root or the stem? Do the seeds sprout sooner in a cool room or in a warm room? Do they sprout in a refrigerator? What happened in the glasses without water?

Be sure to fill out the report page in the back of this booklet.

EXPERIMENT 2

Figure 5. 

The life span of seeds varies from a few weeks to several hundred years, depending upon the kind of plant and how they are stored. Most vegetable seeds will last from three to fifteen years if properly stored. Seeds stored in a cool dry place will live the longest. You should recall from your first experiment that getting seeds wet and warm brought about some changes in them. They germinated, which means they started to grow. This growth required the use of energy. Likewise, moisture and warmth causes stored seed to use up their energy, and they become weak or even die. Vegetable seeds, in general, will last longest if stored at about 50°F. and fairly dry (50 to 70 percent relative humidity).

In this experiment, you are going to find out if "old" seeds germinate as well as new seeds.

Group A (short-lived): onion, corn, beet, and pepper

Group B (medium-lived): beans, carrots, lettuce, and peas

Group C (long-lived): broccoli, cucumbers, turnips, and watermelon

Materials needed.- Old and new seeds, paper towels, rubber bands, half-gallon containers.

Procedure. - Test at least one or two kinds of seeds from each of these groups:

Place several (10 or more) seeds left over from last year or the year before in rows (the same number in each row) on a paper towel. Each row should have the same kind of seed, but you should have two or three rows of different kinds of seeds on one paper towel. For example, on one towel you might have a row of 20 old onion seeds, a row of 20 old beans seeds, and a row of 20 old cucumber seeds.

Then roll up the towel and place a rubber band around it. Stand the rolled-up towel in a half-gallon container. Add about one or two inches of water to the bottom of the container so that the water will be soaked up into the towel like a wick.

For your "controls," repeat the same procedure, but this time use new, fresh seed of the same vegetables. Keep all the towels in the containers for about 3 days. Make sure that you have one or two inches of water in the bottom all the time. Keep the containers in a warm room (from 75° to 90°F.).

Figure 6. 

Then unroll the towels and count the number of seeds that have sprouted. Roll the towels back up and place them back into the water. Count them again in two or three days.

Keep your notebook handy so you can take notes on what you see. Which seeds sprouted best? Did the old seed sprout too?

Now you can figure out the germination percentage for each kind of seed you tested. Here's how. For each kind tested, divide the number tested into the number that germinated. For example, if you tested 20 old onion seed, and 5 germinated, you should divide 20 (number tested) into 5 (number germinated). You would get .25 or 25 percent. The germination percentage for that package of old onion seed from which you get the ones for testing would be 25 percent. Would you want to plant these seed in your garden? You should include the germination percentage in your report which you will find in the back of this booklet.

EXPERIMENT 3

Help from Cotyledons

Cotyledon is a big word. But it is an important word, for it is the part of the seed that contains all the food the little plant (embryo) in the seed will need to grow until it gets roots and leaves. Many seeds, such as peanuts, are eaten because of the rich food stored in the cotyledons.

Cotyledons might be compared to the stored fuel tanks in a manned space capsule. The space craft drifts in orbit for days without using the reserves of fuel. But, when the rockets are fired for re-entry, the fuel reserves are used until the space ship has enough speed to make the trip back.

So it is with a seed. Its "fuel" is stored in "tanks" called cotyledons. These fat, fleshy seed-leaves make up the biggest part of some seeds, such as beans and pea. Most vegetable seeds have two of them. Some, such as sweet corn and onion, have only one and have most of the food stored in a part called the endosperm which is not a direct part of the young plant. This reserve food is not needed until the little plant (embryo) in the seed is ready for "re-entry" back into active growth. Then the embryo uses the reserves for growth until it has grown large enough to make food for itself.

There is a big exception in our comparison. When the space ship's fuel tanks have been used, they are no longer needed. Some plants, however, make further use of thir cotyledons. They use them to help make more food. Bean cotyledons, for example, are carried out of the ground on the stem of the little plant. They appear as the first two leaves. At first they are pale, but then they turn green (chlorophyll) and help make food (photosynthesis).

Figure 7. 

Some vegetables, like peas, leave their cotyledons in the soil. These are not used to help make food, as they are not in the sunlight.

In this experiment you will find out if the cotyledons really do help seedlings.

Materials needed.-Garden bean seeds, containers such a milk cartons, and sandy soil.

Procedure.-Fill two empty milk cartons (half-pint) or other similar containers with sandy soil. Use the same kind of soil in both containers. Punch holes in the bottom for drainage. Plant four bean seeds about one inch deep in each container. Moisten the soil and place the containers in a warm room so the seeds will sprout.

When the first leaves (cotyledons) come out of the soil, you are ready to make your treatments. Do nothing to the beans in one container. These are your "controls." In the other container, cut off both cotyledons from two of the seedlings, and cut off only one from each of the other two bean seedlings.

Figure 8. 

Place them in a spot where they can get sunlight. In the next few days you should keep them watered and observe their growth. You should look for differences in the size of each plant and observe how healthy it is. Since these cotyledons are supposed to make food for the young seedlings, you would expect that seedlings with one or both cotyledons removed would not do as well as the ones in the "control" container.

Keep notes on what you see, and write up your findings in your report located in the back of this booklet.

EXPERIMENT 4

Fertilizer and Plant Growth

Figure 9. 

Fertilizer is a material that contains nutrients (plant foods) which plants need for growth. It is added to the soil where it is taken up by the roots and used to make food and other things needed for plant growth.

There are two kinds of fertilizer. One is natural, or organic, such as the fish the American Indian placed beneath his corn plant years ago. The other is commercial, or inorganic, which man makes and mixes in factories and which is commonly sold in bags.

Figure 10. 

Soils already have some nutrients, but not enough for plants to grow best. Nutrients most often needed in soil by plants are nitrogen, phosphorus, and potassium. Most commercial fertilizers contain large amounts of these three nutrients. You can tell how much by reading the numbers on the bag, such as 4-8-8, 4-7-5, or 5-10-10. If the number is 4-8-8, it means that the mixture inside the bag contains by weight 4 percent nitrogen, 8 percent phosphorus, and 8 percent potassium. The rest of the mixture is filler material such as sand, along with other nutrients that are needed in smaller amounts.

Seeds will germinate even if there are no nutrients in the soil. You found this out by using paper towels to germinate them. This is because of the food stored in the seed cotyledons and endosperm. But when the food in the cotyledons is gone, the plant then needs nutrients to help make its own food. In this experiment, you are going to see for yourself if young plants do need fertilizer and how much.

Materials needed.-Vegetable seeds, containers such as milk cartons, sandy soil, fertilizer, and labels.

Figure 11. 

Procedure.-1. You will need five pint-size cartons. One-quart milk cartons cut in half serve well. Punch three or four drainage holes in the bottom of each container. Label the containers 1 thru 5.

2. Fill each carton to within one-half inch of the top with sandy soil.

3. Add different amounts of fertilizer to each container. To container No. 1, add no fertilizer. This is your control. Add ½ teaspoonful of fertilizer to container No. 2. Add 1 teaspoonful to container No. 3. Add 2 teaspoonfuls to container No. 4. And add 4 teaspoonfuls to container No.5.

Make sure you mix the fertilizer and soil thoroughly. You may use any common garden fertilizer you have available, so long as you use the same kind in each container. Common garden fertilizers are 4-7-5, 4-8-8, 6-8-8, or 5-10-10.

4. Plant two or three seeds in each container. Then, moisten the soil well and set the containers in a warm room. When the seedlings sprout out of the soil, place the containers in a sunny place.

5. Now, watch what happens. Make notes about which ones came up first, which died first, and which were taller, greener, or grew better. How did the "control" plants grow? Do you think fertilizer is needed? Did you notice any injury from using too much fertilizer? You should have a lot to put in your report about this experiment. Use the report forms in the back of this booklet.

Experiment 5

Acid, Alkali, and Chlorophyll

The green color in plants is due to a green pigment known as chlorophyll. It is highly prized and is a sign of freshness in green leafy vegetables and other vegetables.

In raw vegetables, chlorophyll disappears with the aging of the vegetables. Such loss of chlorophyll is due mostly to the chemical changes in its structure. Other colors may then be noticed. For example, a pepper may lose its green color and turn red, and a cucumber may turn yellow. Keeping raw vegetables cool is one of the best ways of keeping their dark green color.

In cooked vegetables, the chlorophyll is not washed out into the cooking water, but does undergo changes due to chemical reactions. Color changes are especially noticeable. Chlorophyll changes to an olive green and then to brown. This depends on such things as acidity of the cooking water and the time and temperature of

cooking. Acids are released in cooking. When these collect in the cooking water, they may cause a loss of dark green color. To neutralize these acids, baking soda (alkali) could be added to the cooking water. However, baking soda should not be added because it destroys some of the vitamins. The best way to keep the green color when cooking is to heat them through as rapidly as possible, then cook for only a short time.

In this experiment, you are going to find out what will happen to chlorophyll when alkali (baking soda) and acid (vinegar) are added to the green vegetables during cooking.

Figure 12. 

Materials needed.-One pound of fresh turnip greens or other green leafy vegetables (about 1 quart of cleaned, trimmed leaves, firmly packed).

3 saucepans (with lids or foil to cover) numbered 1, 2, and 3

Measuring spoons

Measuring cups

Vinegar

Baking soda

3 plates of same color numbered 1, 2, and 3

1 slotted spoon.

Procedure.-

1. Wash leaves through several changes of water. Discard all yellowish, badly injured, and older leaves.

2. Divide leaves into 3 equal portions, and number 1, 2, and 3.

3. Measure ½ cup of water into each saucepan. Add ¼ teaspoon of baking soda to saucepan No. 1, and 1 teaspoon of vinegar to saucepan No. 2. Use only plain water in saucepan No. 3 (your control).

4. Cover each saucepan and bring water to a rapid boil. Remove cover and add one sample of vegetable to each saucepan.

5. Cover each and bring rapidly to a boil. Reduce heat and boil for 10 minutes, leaving cover on.

6. With a slotted spoon, lift each vegetable sample out of the cooking water onto the correspondingly numbered plate.

7. Observe color of each sample. Which sample was the greenest? What caused it to be greener? What effect did the vinegar have on the vegetables? Did the cooking water turn green? Record your observations in your report which is in the back of this booklet.

UNIT I

Beginning Gardening Activities

Those of you who are taking this Beginning Gardening Project should also take part in one or more of the following activities. They are fun to do and will help you get a lot more from your project,

1. Vegetable Demonstrations.-You should participate in a demonstration once a year. If you have ever shown anyone how to make a kite or mix a spray solution, you have given a demonstration. In a vegetable demonstration you show how while you tell about some gardening practice.

There is a 4-H pamphlet which you can get that tells how to prepare a demonstration. It is called "4-H Vegetable Demonstrations." Ask your leader for a copy.

2. Vegetable Judging.-This activity is in the form of a contest. By competing in it you will learn to recognize many important insects, diseases, and weeds that attack your garden. Also, you will learn about kinds and varieties of vegetables, and how to pick the good ones from the bad ones. You might have a chance to be in a club or county contest and test your knowledge of these things. Any of you taking any part of Beginning Gardening may participate in vegetable judging.

Get a copy of "4-H Vegetable Judging, Grading, and Identification Workbook" to find out more about this contest.

3. Exhibiting.-At every opportunity you have, such as at a fair, you should be proud to show others the produce that you have grown. When you show others how well you have done, they may benefit by trying to do as well.

To find out how your vegetables should be exhibited, review the 4-H circular called "Exhibiting and Judging Vegetables."

4. Tours.-Visit the gardens of your neighbors and of other members of your club. Field trips into farming areas are fun and educational. Group trips through local market places to see how produce is sold will be very worthwhile.

4-H GARDENING REFERENCES

Florida Agricultural Extension Service-Gainesville

Vegetable Garden Production Guide

Know Your Vegetables

Hydroponic Culture of Vegetables

Exhibiting and Judging Vegetables

4-H Vegetable Demonstrations

4-H Vegetable Judging, Grading, and Identification Workbook

Florida State Department of Agriculture-Tallahassee

Vegetable Gardening in Florida

U. S. Department of Agriculture-Washington, D. C.

Suburban and Farm Vegetable Gardens

Insects and Diseases of Vegetables in the Home Garden

Light and Plants

Others-especially helpful in workbook area

Potato Grading and Potato Grade Defects, Maine Extension Service Pamphlet 61.

Market Diseases of Potatoes, USDA Misc. Pub. 98.

U.S. Standards for Potatoes, USDA Marketing Service.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.

U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, Dean.

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