Key Area 2.3

Commercial uses of plants

Commercial uses of plants

Learning Intentions: Investigate strategies for increasing yields in cropsInvestigate uses of crops for fuels/food/medicines

Success Criteria: To understand how farmers can increase yields in crop plants.To be able to name the uses of some commercial crops.

Starter Activity: How many things can you name that are made using plants?

2 Minutes- GO!

Answers?

• paper, pencils, car tyres, glue, tea, coffee, sugar, chewing gum, t shirts, chocolate, money, medicines, rope, tissues, cosmetics, cereal, wine, soles of shoes, fences, wallpaper, furniture, bread, book shelves, fuel, fizzy drinks, houses, clothes, crisps……………

Commercial uses of plants

• Plants can be used to produce many different things.– Food, building materials, clothing,

alcohol, fuels, fertilisers, medicines.

Food

• We can eat leaves, tubers, bulbs, fruits and seeds

• Food made from wheat, corn, flour, rice, seeds etc.

Medicines

Plants and medicines

• Many medicines like aspirin are produced from plant products.

Task: Watch the following clip and answer the questions in your book.

Task:

1. What percentage of medicines comes from plant?

2. What can garlic help to reduce?3. What type of tree has been used to

help create anti-cancer medicines?4. What plant is codine extracted from?5. How many people are treated for

malaria each year?

Answers

1. 50%2. Blood pressure, blood sugar, and

cholesterol3. Yew tree4. Opium poppy5. 350 -500 million

Think and Share

• What does a plant need to grow?

• How could you control what a plant needs?

Commercial uses of plants

• Crop plants are usually used for food.

• eg, potatoes, wheat, rice, tomatoes etc

• Farmers use various strategies to produce as much of each crop as possible from their land.

• They are trying to increase their yield, and their profit!

Increasing yield

• The yield of a crop can be increased in various ways.

• The environmental conditions in which a plant grows must be carefully controlled to help increase a crops yield.

• This provides the plants with their optimum conditions.

What plants need to grow

Increasing yield

• What conditions must be controlled?

• Temperature • Humidity• Carbon Dioxide levels• Nutrient levels• Water availability• Air flow

Project• “If farmers can grow many more crops today due to

technology, why are there still food shortages in the world?”

• Research this topic and try to answer the question. Try to include:-

• What crops are grown for food across the world? • Is there enough food to go around? • Why are people starving? • What can governments like ours do?• Is money a factor?

You can present your findings in anyway you like!

Video clips

• BBC Future of food (59 mins)• Feeding nine billion (12 mins)• Getting to grips with the Global food

crisis (14 mins)

Environmental Conditions

Learning Intentions: Investigate strategies for increasing yields in crops

Success Criteria: To understand how farmers can increase yields in crop plants.

Environmental Conditions

• Many crop growers use greenhouses or polythene tunnels to help control environmental conditions.

Environmental Conditions

• Temperature- Greenhouses allow the heat from the sun to enter, but it cannot escape easily so the temperature is usually higher than outside.

• Heaters can also be used to maintain a constant temperature in winter. Vents can be opened in summer to prevent overheating.

Roof vents

Environmental Conditions

• Humidity- Humidity is the amount of water vapour in the air. This can change depending on the temperature, ventilation, the number of plants and how much they are watered. The more humid a greenhouse the less water the plants lose.

• If the humidity is too high, this can encourage the growth of mould, so it is important to monitor humidity levels.

Environmental Conditions

• Carbon Dioxide levels- needed for photosynthesis. More carbon dioxide means faster growth.

• Paraffin heaters release CO2 as well as heat. CO2 is often piped in to speed up growth.

Tulips grown with extra CO2

Environmental Conditions

• Water availability- water is vital for a plant to grow and survive.

• Some greenhouses have automatic watering systems.• Here are some methods of making sure plants get enough

water:Water trickles through pipes to reach each pot

Plants absorb water from the moist matting

H2O

The gels absorb many times their own weight of water, stopping soil drying out

Trickle Irrigation Capillary Matting Water Retentive Gels

Environmental Conditions

• Airflow (ventilation)- good ventilation prevents the air around the plant becoming ‘stale’. This reduces risk of disease and also allows fresh air with CO2 to reach the plants. Fans are also often used to circulate the air.

• Greenhouses and polytunnels can also help protect the crops from frost, disease and pests.

Environmental Conditions• Nutrient levels- the level of nutrients available

to a plant can be increased by using fertilisers. Natural forms can be composts or manure but artificial, chemical based fertilisers can also be used.

• All of these try to increase the levels of Nitrogen (N), Potassium (K) and Phosphorus (P).

Investigating Fertilisers

AimThis aim of this experiment is to investigate if changing the concentration of fertiliser effects seedling growth.•You will need:

– 5 petri dishes– Tub of perlite– 16 seeds– Marker pen– Elastic band

Investigating Fertilisers

Method1.Mark across each petri dish a line 4cm from the bottom. Write your initials and the fertiliser concentration at the top.2.Fill the dish up to the line with perlite.3.Add the correct fertiliser solution to soak the perlite.4.Space 4 seeds out across the top of the perlite.5.Close the dish and secure with an elastic band. 6.Place in tub of liquid fertiliser for 1 week

Results

Concentration of fertiliser (g/L)

Height of plant (cm)

Different Fertilisers

Fertilisers have different chemicals to help plants grow in different ways.

•Nitrogen for leaves•Phosphorus for roots•Potassium for flowers

Advantages of using all of these methods

• Seeds can be germinated earlier in the season.

• Crops will grow faster so can be harvested earlier.

• A larger crop yield is also obtained due to protection from the weather and pests.

• Growers make more money- more crops to sell and less wasted/damaged crops.

Biofuels

Learning Intentions: Investigate strategies for increasing yields in crops for use in biofuels

Success Criteria: To understand how farmers can increase yields in crop plants.

Commercial uses of plants

• Commercially grown crops are grown to produce useful products that we need.

Commercial uses of plants

• Sugar cane and corn contain sugars can be fermented and turned into alcohol. The alcohol is mixed with petrol to form Gasohol.

Commercial uses of plants

• Fuels- Crops such as rapeseed contain vegetable oils that can be processed into biodiesel.

Commercial uses of plants

• Even microscopic plants can be used! Algae naturally produce oils when they grow. These too can be filtered and processed into biodiesel.

How are biofuels made?

• Energy Resources: Biofuels

Advantages/Disadvantages

Advantages•Less demand on fossil fuels.

•Biofuel production is closer to being carbon-neutral than fossil fuels, so is better for the environment.

•Carbon dioxide is taken in by the plants as they grow. This offsets the carbon dioxide released when the fuel is burned.

Advantages/DisadvantagesDisadvantages•It takes large areas of land in order to grow crops for biofuels.

•Biofuels still release greenhouse gases just like fossil fuels.

•Some of the materials are not available all year round.

Pharming

Learning Intentions: Investigate how scientists are genetically engineering plants to produce other products

Success Criteria: To discuss the benefits and disadvantages of genetically engineering plants

Commercial uses of plants

• Plants have been used as the bases of medicines for thousands of years.

• Genetically engineered plants are more commonly being used for the production of medicines, vaccines and hormones.

• This can be known a ‘pharming’-

pharmaceutical farming.

Pharming• Genetically engineered plants can be used to

produced antibodies, enzymes and hormones.

• These can be used to help us fight infection, treat diseases and protect us from further infection.

• Examples- Bananas, Tomatoes, Tobacco , Potatoes Maize, Flax

Group Activity

• Collect a card on either:– Golden Rice– Superspuds– Banana Vaccine– Spider Goat– Flavr Savr Tomato– Venomous Cabbage

• Read the info and discuss with your partner/group whether you agree or disagree with this form of pharming.

Project• You are to research ‘pharming’ and present

your findings to the class.

• You must produce a power point presentation, poster or information leaflet about pharming.

• Things to include- What is pharming? • What crops are used? • What products are produced? • What are they used for? • Advantages and disadvantages? • Future developments?