Section 4 - Growing Crop Plants Flashcards
How can glasshouses and polythene tunnels be used to increase the yield of certain crops?
In glasshouses and polythene tunnels, the conditions can be controlled. This control means that all the limiting factors for plant growth can be set to the optimum conditions; this will result in more growth, so higher yield.
How does the amount of carbon dioxide impact the crop yield?
An increased amount of carbon dioxide (or a higher concentration) causes an increase in the rate of photosynthesis. However, there reaches a point where the rate cannot go any higher.
How does the temperature impact the crop yield?
It is apparent that when the temperature is increased, the rate of reaction taking place inside the crops increase as well, increasing the growth rate. There is also an optimal temperature. However, too much heat can cause the plant to dehydrate, as well as causing the plant to grow baldy. The enzymes can denature.
What are magnesium ions needed for in plants?
Magnesium ions are needed for chlorophyll
What are nitrate ions needed for in plants?
Nitrate ions are needed for amino acids
What do fertilisers do to plants?
Fertilisers contain minerals that plants require to grow; most of them are called NPK fertilisers, this means they contain nitrates, phosphates and potassium.
Nitrates are needed to make proteins - proteins are what plant cells are made of. If there is a lot of nitrate in the soil, then plants have the ability to grow as much as they can.
Phosphates are involved in respiration and growth - both things are needed to sustain a plant
Potassium must be present for enzymes to work. Without potassium, the plant will not be able to carry out reactions and so would die or have very limited growth.
What is the purpose of pest control?
Pests can eat crops or damage them. This makes the crops unsellable. Therefore, pest control is taken place to get rid of these pests.
What are the advantages of pest control?
- Pesticides are used to all pests that reduce crop yield
- The assure that crops won’t be damaged
- Fast and accurate to apply
- Instant results
What are the disadvantages of pest control?
- Pesticides can leech into the soil and possibly pollute rivers or surrounding habitats
- They can harm other wildlife
- Killing the pest may affect biodiversity
- Pests can become immune
What is biological control?
Biological control is introducing a predator into the environment with the crops to kill the pests.
What are the advantages of biological control?
- It is cheap
- It is self regulating
What are the disadvantages of biological control?
- The predator may enter the wild and affect the biodiversity
