Unit B Lesson B12 Plant Growth Technologies
Completion requirements
Lesson B12: Plant Growth Technologies
Video Lesson
Lesson B12: Plant Growth Technologies
Figure B.4.12.1 – Grafting joins branches from different trees.
Figure B.4.12.2 – Tape protects grafted branches until they grow together and are covered by new bark.
Grafting
Grafting is joining two parts of different plants together so they can grow into a single plant. The plants must be similar, of course. Poplar branches will not grow on spruce trees! Grafting is most often used on fruit trees. Usually, a small branch from one fruit tree is inserted into a small cut on another tree so that the growth layers touch.
Grafting is joining two parts of different plants together so they can grow into a single plant. The plants must be similar, of course. Poplar branches will not grow on spruce trees! Grafting is most often used on fruit trees. Usually, a small branch from one fruit tree is inserted into a small cut on another tree so that the growth layers touch.
Sometimes, small branches of equal diameter are cut at angles and held together with tape while they grow together and heal with new bark. Over time, those growing layers join and new bark forms over the wound, and the branches are joined.
People graft fruit trees for several reasons. Fruit seeds do not produce the same type of fruit as the original tree, which is similar to how human children don’t look exactly like their parents. In Alberta, the young fruit tree bought at a garden supply store likely has already been grafted to a wild root that can withstand northern winters better than the original root of the fruit tree can.
Grafting a branch from a parent fruit tree onto a host tree produces the same parent fruit on the new branches that develop on the host tree. Also, grafting results in the production of fruit quicker than production from new trees started from seed. Sometimes branches are grafted onto a tree that is very resistant to disease, which protects the grafted plant.
People graft fruit trees for several reasons. Fruit seeds do not produce the same type of fruit as the original tree, which is similar to how human children don’t look exactly like their parents. In Alberta, the young fruit tree bought at a garden supply store likely has already been grafted to a wild root that can withstand northern winters better than the original root of the fruit tree can.
Grafting a branch from a parent fruit tree onto a host tree produces the same parent fruit on the new branches that develop on the host tree. Also, grafting results in the production of fruit quicker than production from new trees started from seed. Sometimes branches are grafted onto a tree that is very resistant to disease, which protects the grafted plant.
Reading and Materials for This Lesson
Science in Action 7
Materials:
Reading: Pages 150–155
Materials:
two empty 2 L plastic pop bottles, scissors, strip of cotton fabric 15 cm by 4 cm, perlite, liquid fertilizer, water, bean seeds, clear plastic bag, potting soil, big bowl, two plastic cups, glass or metal pan or tray, measuring cups,
measuring spoons, ruler
Watch More
Forty Fruits on One Tree
Watch this video to see a grafted tree that grows 40 kinds of fruit. Exceptional!
Watch this video to see a grafted tree that grows 40 kinds of fruit. Exceptional!
Here’s a “how-to-do-it” video about grafting that shows how simple the process can be. Perhaps you can help your family to produce a new fruit tree! The process shown can be used to add another variety of apple to a branch of an existing apple tree, too.
Hydroponics
In the Greek language, the word “hydro” means “water” and the word “ponos” means “work”. Putting them together makes “hydroponics”, which means “water work”. Hydroponics is
the process of using nutrient-rich water to grow plants without soil.
Hydroponics is especially useful for growing crops in dry areas with poor soil, but it is useful in our greenhouses, too. In hydroponics, plant nutrients are from fertilizer and not from the soil. Because hydroponically-grown plants require less water than soil-grown plants, hydroponics can increase local food production in climates in which growing crops is challenging.
In the Greek language, the word “hydro” means “water” and the word “ponos” means “work”. Putting them together makes “hydroponics”, which means “water work”. Hydroponics is
the process of using nutrient-rich water to grow plants without soil.
Hydroponics is especially useful for growing crops in dry areas with poor soil, but it is useful in our greenhouses, too. In hydroponics, plant nutrients are from fertilizer and not from the soil. Because hydroponically-grown plants require less water than soil-grown plants, hydroponics can increase local food production in climates in which growing crops is challenging.
Figure B.4.12.3 – Water runs through big pipes over the roots of hydroponically grown plants.
Figure B.4.12.4 – Hydroponics is a way to grow plants without using soil.
Watch More
Hydroponics
Watch this video to learn more about how hydroponics is used successfully in African communities with limited water and electricity.
Watch this video to learn more about how hydroponics is used successfully in African communities with limited water and electricity.
Watch this video to see a massive greenhouse containing hydroponically-grown tomatoes.
Try It!
Pop Bottle Hydroponics
Try this simple experiment to grow a plant using hydroponics.
Materials:
- empty 2 L plastic pop bottle
- scissors
- strip of cotton fabric, 25 cm by 4 cm (You can use part of an old t-shirt.)
-
perlite
- liquid fertilizer (such as used for house plants)
- water
- bean seeds
-
clear plastic bag
Safety Warning
Take care with scissors; don't cut yourself or anyone else!
Instructions:
-
Cut the plastic pop bottle in two, making the cut two-thirds up from the bottom of the bottle – right at “the shoulder” of the bottle works well. You will now have a sort of jug and a funnel.
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Push the strip of cotton fabric through the spout of the top of the bottle (the funnel-shaped piece). Half of the fabric strip should extend from the spout, but keep a short bit in the top, too. Scrunch some of the fabric into the bottle spout to plug
the spout.
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Fill the bottom of the bottle half full of water.
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Add 3 capfuls (about 3 teaspoons) of liquid houseplant fertilizer to the water.
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Place the bottle top into the bottle bottom – spout down, of course. The cloth will now be hanging into the water of the bottom container as well as plugging the spout.
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Fill the top of the bottle with perlite. The top end of the cotton strip should extend straight up through the perlite and poke out the top a little.
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In the top of the bottle, plant 5 bean seeds 1 cm deep into the perlite. Cover the seeds with a thin layer of perlite.
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Place the hydroponics bottle in a sunny window.
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Cover the hydroponics bottle loosely with a clear plastic bag to prevent it from drying out. (Do not tie the bag!)
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Observe the hydroponics bottle for 3 weeks. Repeat steps 3 and 4 if the water in the bottom disappears.
Questions:
Think about the following questions very carefully. Then, type or write your answers. After you have your answers, click the questions for feedback.
Think about the following questions very carefully. Then, type or write your answers. After you have your answers, click the questions for feedback.
Nutrients are provided by the liquid fertilizer.
How did water and nutrients move into the plant roots? What is the scientific name for this process?
Water and nutrients dissolved in the water moved into the plant roots by travelling up the cotton strip to the roots. This process is called capillary action, familiar to many as the action of a wick.
Urban Farming
Cities have limited amounts of land and soil. This makes production of edible crops difficult in cities. Some people are finding creative ways to grow food in cities. Already many cities have garden plots along railway tracks, under power lines, within highway interchanges, or on open lots. Recently, “urban farmers” have looked to the potential of roofs of buildings as large, flat surfaces exposed to lots of sunlight. Some urban farmers have transported soil to skyscraper roofs and have started vegetable gardens.
Another innovative way of farming in the city is to grow plants vertically instead of horizontally. Vertical farming uses hydroponics in tall buildings to grow plants in layers – similar to shelves of plants, sometimes moving shelves!
Cities have limited amounts of land and soil. This makes production of edible crops difficult in cities. Some people are finding creative ways to grow food in cities. Already many cities have garden plots along railway tracks, under power lines, within highway interchanges, or on open lots. Recently, “urban farmers” have looked to the potential of roofs of buildings as large, flat surfaces exposed to lots of sunlight. Some urban farmers have transported soil to skyscraper roofs and have started vegetable gardens.
Another innovative way of farming in the city is to grow plants vertically instead of horizontally. Vertical farming uses hydroponics in tall buildings to grow plants in layers – similar to shelves of plants, sometimes moving shelves!
Figure B.4.12.5 – Soil is moved to the top of a skyscraper to grow plants in Hong Kong.
Figure B.4.12.6 – Rooftop gardens are exposed to lots of sunlight.
Watch More
Rooftop Farming
This video explains how sunny unused rooftops in New York City are used to grow fresh vegetables.
This video explains how sunny unused rooftops in New York City are used to grow fresh vegetables.
Vertical Farming
Watch this video to see a vertical hydroponic farm in Singapore, a small urban country where very little land is available to grow plants in soil.
Watch this video to see a vertical hydroponic farm in Singapore, a small urban country where very little land is available to grow plants in soil.
Indoor Farming
Growing plants indoors has some advantages over growing plants outdoors. Indoor plants can be grown year-round in a controlled environment – that’s control of heat, light, and air. Herbicides (weed killers) or pesticides (insect killers) are not needed
because indoor plants are not exposed to harmful weeds or insects.
Indoor plants still require light to make food by photosynthesis. Indoor plants in glass-walled greenhouses are exposed to lots of sunlight. Glass greenhouses are a good way to help plants grow in slightly cool temperatures, but they are not ideal for growing plants in freezing winter weather. Glass is a very poor insulator, and the cost of heat is very high.
Growing plants indoors without natural light can be done economically using LED lights. LED stands for “light-emitting diodes”. LED lights use very little electricity, so they are an energy- efficient way to grow indoor crops. In fact, you could grow lettuce and radishes easily in a planter in your house throughout winter with some LEDs!
Indoor plants still require light to make food by photosynthesis. Indoor plants in glass-walled greenhouses are exposed to lots of sunlight. Glass greenhouses are a good way to help plants grow in slightly cool temperatures, but they are not ideal for growing plants in freezing winter weather. Glass is a very poor insulator, and the cost of heat is very high.
Growing plants indoors without natural light can be done economically using LED lights. LED stands for “light-emitting diodes”. LED lights use very little electricity, so they are an energy- efficient way to grow indoor crops. In fact, you could grow lettuce and radishes easily in a planter in your house throughout winter with some LEDs!
Figure B.4.12.7 – Glass greenhouses expose plants to lots of sunlight.
Figure B.4.12.7 – LED lights are used to grow plants indoors.
Figure B.4.12.7 – Plants are stacked in layers with LED lights in indoor factory farms.
Watch More
Indoor Farming
This video shows an indoor farm in an office building in Tokyo, Japan.
This video shows an indoor farm in an office building in Tokyo, Japan.
Urban Farming in Tokyo from imageMILL on Vimeo.
LED Lights
This video explains how LED lights are used in urban farming.
This video explains how LED lights are used in urban farming.
Lesson Activity
Greenhouse Growth
Do greenhouses help plants to grow faster? Try this experiment to find the answer.
In this experiment, you will measure the height of two plants over time. One plant will be in a greenhouse, and the other plant will be open (without the protection of a greenhouse). You will try to keep the amounts of soil, water, and light the same to make the experiment fair.
Do greenhouses help plants to grow faster? Try this experiment to find the answer.
In this experiment, you will measure the height of two plants over time. One plant will be in a greenhouse, and the other plant will be open (without the protection of a greenhouse). You will try to keep the amounts of soil, water, and light the same to make the experiment fair.
Materials:
- potting soil
- perlite
- large bowl
- 2 plastic cups
- glass or metal pan or tray
- empty 2 L plastic pop bottle
- scissors
- water
- measuring cups
- measuring spoons
- ruler
-
bean seeds
Safety Warning
Take care with scissors; don't cut yourself or anyone else!
Quick Question:
This experiment has manipulated, responding, and controlled variables. Do you know which is which? Think about it, then click for the answer below.
This experiment has manipulated, responding, and controlled variables. Do you know which is which? Think about it, then click for the answer below.
This experiment is interested in how fast plants grow under certain conditions. The growth of the plants (their height) is the responding variable. One thing has been manipulated or changed in this experiment - whether the plant is in
a greenhouse. That is the manipulated variable. We can keep control variables the same to be sure the experiment is fair. This experiment has several control variables: the amount of soil, the amount of light, the temperature,
and the type of plant used.
Download:
DOWNLOAD this document. It provides a space for you to write answers to questions later in this activity. It also provides a chart for you to record your observations.
Instructions:
DOWNLOAD this document. It provides a space for you to write answers to questions later in this activity. It also provides a chart for you to record your observations.
Instructions:
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With the scissors, poke a hole into the bottom of each plastic cup.
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Cut the spout off the 2 L plastic pop bottle. (Cut far enough down the slope of the neck so the opening of the bottle can fit over the plastic cup.)
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In the large bowl, mix 4 cups of potting soil and 2 cups of perlite.
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Use a measuring cup to measure the same amount of soil into each plastic cup. (The cups must have the same amounts of the mixture of potting soil and perlite.)
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Over a sink, add 1/8 cup of water to each plastic cup. (Pour very slowly to avoid spills.)
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Into each cup, place 1 bean seed about 1 cm into the soil mixture, covering the seed.
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Put both plastic cups on the pan or tray.
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Place the pop bottle over one of the plastic cups. The pop bottle will act as a greenhouse.
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Put the plants in their tray in a sunny window.
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At the same time every day for 20 days, add 1 tablespoon of water to each plant. (Be exact. This is a science experiment!)
Hypothesis:
Write what you think will happen in this experiment.
Write what you think will happen in this experiment.
- Which bean seed will grow the fastest? Why?
- Which bean seed will grow the slowest? Why?
Observations:
-
After you add water to the plants each day, measure the height of each plant stem. (Measure from the soil to the top of the stem.)
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Observe the appearance of each plant.
- Record the height measurements and your observations in a chart such as the one below:
Questions:
Think about the following questions very carefully. Refer to the height measurements and observations of the bean seeds you recorded. Then, type or write your answers. When you have your answers, click the questions for feedback.
Think about the following questions very carefully. Refer to the height measurements and observations of the bean seeds you recorded. Then, type or write your answers. When you have your answers, click the questions for feedback.
Water drops formed on the walls of the greenhouse, showing that the greenhouse produced a moist (humid) environment. This caused the soil of the plant in the greenhouse to stay more moist than the soil of the plant in the open. It was also warmer inside
the greenhouse than outside.
The bean seeds in the greenhouse sprouted and grew faster than the bean seeds sprouted and grew in the open.
The bean seeds in the greenhouse sprouted and grew faster than the bean seeds sprouted and grew in the open.
Bean seeds grow well in warm conditions. Also, they grow well in moist air that helps the to keep the soil moist. Greenhouses provide warm, humid conditions that are ideal for the growth of bean plants.
Make sure you have understood everything in this lesson. Use the Self-Check below, and the Self-Check & Lesson Review Tips to guide your learning.
Unit B Lesson 12 Self-Check
Instructions
Complete the following 6 steps.
Don't skip steps – if you do them in order, you will confirm your
understanding of this lesson and create a study bank for the future.
- DOWNLOAD the self-check quiz by clicking here.
- ANSWER all the questions on the downloaded quiz in the spaces provided. Think carefully before typing your answers. Review this lesson if you need to. Save your quiz when you are done.
- COMPARE your answers with the suggested "Self-Check Quiz Answers" below. WAIT! You didn't skip step 2, did you? It's very important to carefully write out your own answers before checking the suggested answers.
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REVISE your quiz answers if you need to. If you answered all the questions correctly, you can skip this step. Revise means to change, fix, and add extra notes if you need to. This quiz is NOT FOR MARKS, so it is perfectly OK to correct
any mistakes you made. This will make your self-check quiz an excellent study tool you can use later.
- SAVE your quiz to a folder on your computer, or to your Private Files. That way you will know where it is for later studying.
- CHECK with your teacher if you need to. If after completing all these steps you are still not sure about the questions or your answers, you should ask for more feedback from your teacher. To do this, post in the Course Questions Forum, or send your teacher an email. In either case, attach your completed quiz and ask; "Can you look at this quiz and give me some feedback please?" They will be happy to help you!
Self-Check Time!
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Self-Check Quiz Answers
Click each of the suggested answers below, and carefully compare your answers to the suggested answers.
If you have not done the quiz yet – STOP – and go back to step 1 above. Do not look at the answers without first trying the questions.
Cities have little available soil to grow plants. Using hydroponics allows plants to be stacked in vertical layers, reducing the need for land.
Hydroponic plants do not need to be sprayed with herbicides or pesticides that might have other harmful effects. Because hydroponic plants grow without soil, fertilizer is not added to the ground. Therefore, it is not carried into waterways.
Because hydroponics does not use soil, the lettuce plants could not obtain nutrients from the soil. Because no fertilizer was added to the hydroponics water, the lettuce had no way to get nutrients from the water. The lettuce plants probably
did not grow very large as a result.
Greenhouses maintain warm temperatures for plants, and they keep the air moist, which stops soil from drying.
Various technologies help increase the yields of crops. The yield is the amount of useful materials that is harvested from a crop.