Unit 2 – Area of Study 1: Plant nutrition, growth and reproduction

Outcome 1

Analyse the growth stages of plants, describe plant genetics and reproduction, and demonstrate the propagation of plants and the measurement of plant growth.

Examples of learning activities

• Browse the Agriculture Victoria website to find examples of current challenges affecting plant production in Australian agriculture and horticulture. Choose one challenge, explain it and investigate the proposed solutions, including their likelihood of success in solving the problem
• Watch the ABC Education video Growing mushrooms in coffee grounds (5:21 mins). Discuss what challenge to agriculture/horticulture is being addressed with this novel solution.
• View the series of three videos on the Department of Education’s FUSE website: Photosynthesis, Crash Course Biology #8 (13:14 mins), Photosynthesis and respiration (6:10 mins), Xylem and phloem part 2 – Transpiration (3:55 mins). Note how they explore the basics of photosynthesis, respiration and transpiration and discuss their roles in plant growth and survival.
• Conduct a practical investigation to examine transpiration processes in action; for example, through covering plant cuttings with plastic bags overnight.
• Create representations showing the key structures of different types of plants. As a class, compare and contrast the structures seen in these plant types and construct a Venn diagram to illustrate similarities and differences.
• Explore general stages of plant growth using models or images of developing plants, focusing on common Australian crops.
• Create a visual display of the different growth stages of common horticultural and agricultural plants used in Australia; for example, fruit trees, vegetables, wheat, barley or cotton.
• Grow seedlings of quick germinating plants to view growth stages of plants and their development in real time.
• Undertake a jigsaw activity in which groups of students research one of the five major types of plant hormone: auxin, gibberellin, cytokinin, ethylene or abscisic acid (ABA). Identify the hormone’s origin, function and relative importance to normal plant growth. Each group then shares a description of their findings with the class.
• Define the terms ‘macronutrient’ and ‘micronutrient’. Explore examples of each and discuss their role in plant growth.
• Investigate case study examples of nutrient deficiencies causing low yield in horticultural/agricultural plants.
• Research and report on the role of one key nutrient (such as nitrogen or phosphorus) in the growth of a food or fibre plant.
• 
  Conduct a practical investigation into the role of a key nutrient in plant propagation and growth, including the monitoring of growth using technology as appropriate.
• Investigate the times of year when key Australian crops are planted and harvested, and discuss reasons why following a seasonal calendar is important.
• Develop and justify an informed opinion regarding the importance of producing and selling plants for food in their natural season.
• Create a visual or interactive display to illustrate the key stages of sexual and asexual plant reproduction.
• Identify examples of agricultural and horticultural plants that reproduce sexually (such as wheat) or asexually (such as tubers undergoing vegetative reproduction) and compare how they are propagated and managed.
• Investigate the role of gene selection in plant breeding through case studies such as Mendel’s peas, as well as modern agricultural examples. The Department of Education has a useful web page containing two videos about ‘Mendel’s peas’: TEDEd video (3:06 mins) and information from Khan Academy. Another resource is the CSIRO’s Plant science webpage.
• Use the Australian Grain Technology (AGT) The science of plant breeding webpage to explore processes involved in plant breeding. (Note: AGT is Australia’s largest plant-breeding company, owned by both private and public research and development agencies).
• Investigate examples of genes and associated traits, such as drought tolerance, that have been selected for in the breeding of Australian agricultural or horticultural plants. Justify their selection for plant breeding in this context.
• Explore how the wild mustard plant was selectively bred to produce a wide range of modern vegetables by referring to the Department of Education’s FUSE resource ‘Brassica oleracea: Wild mustard selective breeding’ (a Business Insider article).
• Use the Agriculture Victoria website to identify and investigate emerging technologies that may improve plant production.
• Research a new or emerging technology for plant production. Present the pros and cons of using this technology for a given problem and draw a conclusion based on the available evidence.
• Watch ABC Education’s video Developing robotic farm machinery (4:40 mins) to explore the potential for robotics in farming, with a focus on increasing plant yields.
• Create a report on the science of ‘no-till’, ‘controlled traffic’ and/or ‘regenerative’ farming as methods for increasing plant yields.
• Investigate the following quote: ‘Precision farming combines sensors, robots, GPS, mapping tools and data-analytics software to customise the care that plants receive without increasing labour … [It] can improve time management, reduce water and chemical use, and produce healthier crops and higher yields’ (Scientific American, June 2017).
• Define and explain the concept of ‘post-harvest loss’. Why is global action on this becoming more important over time? How can such losses be reduced, both in Australia and elsewhere?

 

Detailed example

Practical investigation into the role of a key nutrient in plant propagation and growth

This activity involves conducting research into the key factors required to grow a crop such as wheat or barley; for example, through the guide available on the Agriculture Victoria website. Teachers can refer to the scientific methodology outlined on page 8 of the VCE Agricultural and Horticultural Studies Study Design for guidance in planning and implementing the activity.

[Note: the following guidelines refer to phosphorus as the sample key nutrient for investigation.]

1. Students select one horticultural/agricultural plant and one key nutrient (such as phosphorus or nitrogen). For a practical experiment monitoring plant growth, the selected plant must be propagated/grown in a suitable time frame.
2. Teachers set guiding questions for the selected plant, such as:
• Where is the plant grown in Victoria and throughout Australia?
• What are the climate conditions like in these areas?
• How much rain do these areas typically receive in a year?
• What kind of growing media/soil is the plant usually grown in?
• Why does the plant need this kind of soil?
• What are the key macronutrients and micronutrients it needs in order to grow?
• What happens to the plant's growth and appearance when these nutrients are missing or deficient?
3. Teachers set guiding tasks and questions for setting up a growth-monitoring exercise, such as:
• Can the plant be propagated and grown in a suitable time frame for this exercise?
• Set up an experiment to evaluate the importance of phosphorus to the early growth of this plant.
• The experiment should contain a control group of plants (receiving no additional resources beyond the growing media and water), a group in low-phosphorus soil and one that receives additional phosphorus through fertiliser at the time of sowing.
  [Note: Soil testing kits can be purchased from gardening stores and should be used with appropriate safety equipment.]
• Identify the controls that need to be placed on the experiment to ensure the results are accurate and valid.
• How much water will each group of plants receive?
• How many seeds will be sown in each group? How will they be spaced evenly?
• How much growth media is the appropriate amount?
• How is it possible to ensure that all plants receive the same amount of sunlight?
4. Students sow and monitor the plants over time. They record the time taken to germinate, number of seedlings, appearance of plants and their parts, height of seedlings and make general observations. This can be done using a results template and the taking and storing of digital images. These images can be shared and annotated via the school intranet or through systems such as Google Drive.
   [Note: Safety when handling growth media and fertiliser should be a priority. Teachers should refer to the Safe Work Australia website for a Material safety data sheet; conduct a risk assessment and follow all safety directions for products used throughout the process.]
5. After an agreed-upon length of time (related to the germination time of the chosen plant), students finalise the collection of data and analyse the results.
6. Teachers set guiding questions for this analysis, such as:
• Which experimental group showed the quickest germination time?
• Which experimental group showed the most growth across the experiment? Which method is best to determine the 'most growth'?
• What impact did phosphorus-deficient soil have on the growth of the plants?
• What impact did the addition of phosphorus-rich fertiliser have on the growth of the plants?
• Which of the experimental groups produced plants that appear to be the most robust and healthy? How did you make this conclusion?
• Based on your experimental results, how important are macronutrients, such as phosphorus, to the efficient growth of crops? Justify your answer.
• An important sustainability consideration for growing plants for food or fibre production is the effect of fertiliser 'run off'. Investigate what this term means, how it can affect the environment and how it would need to be considered when applying phosphorus to crops.
7. Students present their method, results and conclusions to the class using a multimedia tool such as MS PowerPoint, Prezi or Google Slides. Compare any differences in results between groups and discuss why they may have occurred.