Increasing Plant Production

1. Increasing Plant Production AS 91290 Demonstrate understanding of techniques used to modify physical factors of the environment for NZ plant production

2. Contents • THE BASICS • Photosynthesis, respiration, transpiration, nutrient uptake, water uptake. • Liebig’s Law of the Minimum • PLANT GROWTH • Bud formation, flowering, pollination, fertilisation, fruit set, germination, maturation, ripening. • ENVIRONMENTAL FACTORS • light, sunlight hours, temperature (Growing Degree Days (GDDs) or heat units (HUs)), frost, chill requirements (as expressed by chill units), rainfall, humidity, wind, soil type, topography. • TECHNIQUES (see PPT number 2) • CO2 enrichment, artificial shelter, sprinkler irrigation, tile drainage, hail cannon, wind machines, reflective mulch, training systems.

3. Plant Processes There are 6 key processes that happen inside a plant • Photosynthesis • Respiration • Transpiration • Nutrient Uptake • Water Uptake • Fertilisation/pollination Plants having sex to produce viable seeds and fruit Learn how to spell these! Converting light energy to chemical energy Using chemical energy to grow and function Getting water from the roots to the leaves Getting macro and micro nutrients into the plant Getting water from the growing media into the roots

4. Photosynthesis Light energy + chlorophyll Water + Carbon Dioxide  Glucose + Oxygen H2O + CO2  C6H12O6 + O2 Converted to Carbohydrates (eg starch)

5. Photosynthesis • Photosynthesis (echalk)

6. Photosynthesis Is a chemical reaction occurring in the chloroplasts found inside plant cells • One purpose of the photosynthesis is to convert light energy to chemical energy to be used by the plant. • The other purpose is to create the molecule glucose that can then be used to build cell components

7. Capturing Energy • The chemical energy is initially in glucose but the plant converts some of the glucose into starch for long term storage. • The energy is released in respiration to ‘power’ other cell processes such as the formation of proteins and lipids.

8. Photosynthesis - Chlorophyll • Chlorophyll is a green pigment inside the chloroplasts found in plant cells. • Chlorophyll is essential for photosynthesis • What are the essential nutrients needed for chorophyll? You do not need to learn the structure of chlorophyll

9. Photosynthesis – light absorption So why are plants green? Chlorophyll does not absorb green light – instead it reflects green light and it bounces back off the plant into your eye and the plant (leaf) looks green. So what colour light should plants be exposed to?

10. Respiration Oxygen + Glucose  Water + Carbon Dioxide O2 + C6H12O6 H2O + CO2 Energy released This energy is the useful output of respiration The energy is released in respiration to ‘power’ other cell processes such as the formation of proteins and lipids

11. Respiration • The purpose of respiration is to release the energy from glucose. • The water and carbon dioxide are waste products and most of the water and carbon dioxide exit the plants through the stomata. • Respiration occurs in all living cells in the plant. Consequently oxygen is needed in all parts of the plants including the roots

12. Summary diagram showing the relation- ship between photosynthesis and respiration

13. Transpiration • Transpiration is the process of water movement into the roots. Up the stem and out of the stomata in the leaves.

14. Transpiration • Plant transpiration is pretty much an invisible process—since the water is evaporating from the leaf surfaces, you don't just go out and see the leaves "sweating". Just because you can't see the water doesn't mean it is not being put into the air, though. During a growing season, a leaf will transpire many times more water than its own weight. A hectare of corn gives off about 30,000-45,000 liters of water each day, and a large oak tree can transpire 151,000 liters per year.

15. Respiration • Glucose + Oxygen  Carbon Dioxide + Water

16. Carbon dioxide (CO2)is an essential component of photosynthesis (also called carbon assimilation). Photosynthesis is a chemical process that uses light energy to convert CO2 and water into sugars in green plants. These sugars are then used for growth within the plant, through respiration. The difference between the rate of photosynthesis and the rate of respiration is the basis for dry-matter accumulation (growth) in the plant.

17. Dry matter accumulation • Carbon dioxide (CO2)is an essential component of photosynthesis (also called carbon assimilation). Photosynthesis is a chemical process that uses light energy to convert CO2 and water into sugars in green plants. These sugars are then used for growth within the plant, through respiration. The difference between the rate of photosynthesis and the rate of respiration is the basis for dry-matter accumulation (growth) in the plant.

18. Nutrient Uptake • Nutrients are up taken via the roots of the plant.

19. What is the optimum soil pH range?

20. The plant, through photosynthesis, fixes carbon dioxide and water in the form of sugars. The sugars are used in respiration to provide energy - breaking down again to carbon dioxide and water. Some sugars are synthesize into amino acids and finally proteins, the building blocks of living tissue.

22. Liebig’s Law of the minimum • States that growth is controlled not by the total of resources available, but by the scarcest resource (limiting factor). • This concept was originally applied to plant or crop growth, where it was found that increasing the amount of plentiful nutrients did not increase plant growth. Only by increasing the amount of the limiting nutrient (the one most scarce in relation to "need") was the growth of a plant or crop improved.

23. Liebig’s Law of the minimum - explained The water level in the barrel represents plant growth. By adding more light, Phosphorus, warmth etc there will be no further increase in growth. What is the limiting factor? Nitrogen

24. Effect of Light and Water on Plant Production Click here for explanation

25. Kiwifruit Data Exercise

26. Inside a leaf

27. Stomata

31. Site Establishment

32. Pests and Diseases • Pests and diseases can influence the crop that can be grown in a certain region, ie apples aren’t grown in the Waikato and grapes are no longer commercially grown in West Auckland due to dampness of the climates (botrytis). • New growth of all plants are very susceptible to pests and diseases. • Pests chew the tender tasty tips of plants restricting the development of the plants and their ability to carry out plant processes. • Fungi such as mildew destroy apical buds. • Pests chew the plants providing an entry point for diseases which restricts the ability of the plant to grow at an optimum rate.

33. Aphids sucking the growing shoot of a rose Aphids sucking sap from cabbages Mildew on growing tip Grassgrubsunderturf Clean Infected

34. Plate 1. Carbon dioxide generator. Plates 6b. Liquid CO2 tanks. • CO2 Enrichment Liquid Carbon dioxide tank supplying a greenhouse. Carbon dioxide generator for a large greenhouse (burns fossil fuels to generate CO2

35. CO2 Enrichment • Normal CO2 level in outside air is about 340 ppm (0.3%). All plants grow well at this level but as CO2 levels are raised by 1,000 ppm photosynthesis increases proportionately resulting in more sugars and carbohydrates available for plant growth. • Any actively growing crop in a tightly clad greenhouse with little or no ventilation can readily reduce the CO2 level during the day to as low as 200 ppm. The decrease in photosynthesis when CO2 level drops from 340 ppm to 200 ppm is similar to the increase when the CO2 levels are raised from 340 to about 1,300 ppm

36. Fruit Development • Which of the following Horticultural products do not develop from a flower. • Strawberries • Bannanas • Carrots • Beans • Peas • Pumpkin • Corgetts • Tomatos

37. Fruit Development • 5 stages of fruit development • Bud set • Bud burst • Pollination/ fertilisation • Fruit development • Fruit ripening

38. Link the five stages of fruit development with an image Bud set Bud burst Pollination/ fertilisation Fruit development Fruit ripening Then give each a definition

40. Environmental factors affecting fruit development