Objective of the module



Download 133,45 Kb.
Page5/5
Date conversion04.03.2018
Size133,45 Kb.
1   2   3   4   5

EDIBLES

1. VEGETABLES

1.1 Plants Grown for aerial portions


  1. Cole Crops (broccoli, cabbage, cauliflower)

  2. Legumes or pulse crops (bean, pea)

  3. Solonaceous fruit crops (Capsicum pepper, eggplant, tomato)

  4. Vine crops or curcubits (cucumber, melon, squash and pumpkin)

  5. Pot Herbs or Greens (chard, dandelion, spinach)

  6. Mushrooms (Agaricus, Oyster, Lentinus)

  7. Other vegetables (asparagus, okra, sweet corn)


1.2 Plants grown for underground portions

  1. Root crops

    • Temperate (beet, carrot, radish and turnip)

    • Tropical (cassava, sweetpotato, taro and yam)

  2. Tuber crops (Jerusalem artichoke, potato)

  3. Bulb and corm crops (garlic, onion, shallot)


2.0 FRUITS

2.1 Temperate (Deciduous)



  1. Small fruits

    • Berries (blueberry, cranberry, strawberry)

    • Brambles (blackberry, raspberry)

    • Vines (grape, kiwifruit)

  2. Tree fruits

  • Pome fruits (apple, pear, quince)

  • Stone fruits (apricot, cherry, peach and plum)

2.2 Subtropical and tropical (Evergreen)


  1. Herbaceous and vine fruits (banana, papaya, passion fruit, pineapple)

  2. Tree fruits


    • Citrus (grapefruit, orange, lime, lemon, naartjies, mandarin)

    • Non citrus (avocado, date, fig, mango, mangosteen)


3.0 NUTS

  1. Temperate (almond, chestnut, filbert, pecan, pistachio)

  2. Tropical (Brazil nut, cashew, macadamia)


4.0 BEVERAGE CROPS

  1. Seed (cacao, coffee)

  2. Leaf (maté, tea)


5.0 HERBS AND SPICES

  1. Culinary herbs (dill, rosemary, sage)

  2. Flavourings (peppermint, spearmint)

  3. Tropical spices (cinnamon, clove, nutmeg and pepper)



ORNAMENTALS


1.0 FLOWERS , BEDDING AND FOLIAGE PLANTS

  1. Annuals (marigold, petunia, zinnia)

  2. Biennials (English daisy, foxglove)

  3. Perennials (daylily, rose, delphinium, iris, peony)

    • Bulbs and corms (crocus, gladiolus, narcissus, tulip)

2.0 LANDSCAPE (NURSERY)

  1. Lawn and turf (bermudagrass, bluegrass, fescue, perennial ryegrass)

  2. Ground covers and vines (English ivy, Japanese spurge, myrtle)

  3. Evergreen shrubs and trees

    • Broadleaf (holly, rhododendron)

    • Narrowleaf (fir, juniper and yew)

  4. Deciduous shrubs (dogwood, forsythia, lilac, viburnum)

  5. Deciduous trees (ash, crabapple, magnolia, sugar marple)


3.0 INDUSTRIAL

  1. Drugs and medicinals (digitalis, quinine)

  2. Oil seeds (jojoba, oilpalm, tung)

  3. Extractives and resins (Scotch pine, Pará rubber tree)


2.0 TAXONOMY OF PLANTS

2.1 Hierarchy

2.2 Classification process

2.3 Natural and artificial classification



3.0 LIGHT AND PLANT FLOWERING

3.1 Photoperiodism

3.2 Mechanism of photoperiodism

4.0 PLANT GROWTH REGULATORS (PGRs)

4.1 Auxins

4.2 Gibberellins

4.3 Cytokinins

4.4 Abscisins

4.5 Ethylene

4.6 Hormonal control of the whole plant

4.7 Use of PRGs in horticulture



5.0 VEGETATIVE PROPAGATION

5.1 Cloning in horticulture

5.2 Propagation by layering

5.3 Propagation by Grafting and Budding

5.3 Graft incompatibility

5.4 Propagation from cuttings

5.5 External and internal factors affecting rooting of cuttings

6.0 TISSUE CULTURE

6.1 Micropropagation (Its applications, advantages and disadvantages)

6.2 Embryo culture

6.3 Somatic embryogenesis

6.4 Meristem tip culture

6.5 Anther culture

6.6 Protoplast culture

6.7 Somaclonal variation

6.8 Invitro selection

7.0 PROPAGATION STRUCTURES

7.1 Greenhouses

7.2 Lathhouses

7.3 Hotbeds

7.4 Cold beds

8.0 IRRIGATION AND NUTRITION MANAGEMENT IN HORTICULTURE

8.1 Soil Moisture and its measurement

8.2 Irrigation methods

8.3 Essential element for plant growth



9.0 POSTHARVEST TECHNOLOGY

9.1 Deterioration of produce

9.2 Ethylene production

9.3 Compositional changes

9.4 Physiological breakdown

9.5 Effects of temperature, RH, atmospheric gases, ethylene and light

9.6 Harvesting

9.7 Storage

CHAPTER 2.0 TAXONOMY OF PLANTS

SCIENTIFIC CLASSIFICATION OF PLANTS




  1. PRACTICAL 1: IDENTIFICATION OF COMMON HORTICULTURAL CROPS




Full Name : …………………………………………………



Registration Number :…………………………………………………...




SAMPLE CODE

NAME OF CROP

FAMILY OF CROP

A







B







C







D







E







F







G







H







I







J






Assignment


  1. Advise smallholder farmers of the challenges or hardships they are likely to face in commercial horticultural production [10]

  2. Write a short essay on the importance of classifying horticultural crops [10]

CHAPTER 4.0 Plant Hormones (Plant Growth Regulators)

Introduction

As a plant grows its physical traits, or phenotype, are the outcome of a complex interaction between its genetic instructions, or genotype, and the external environment. The growth and differentiation of cells in different parts of the plant are coordinated in response to these inputs.

There has to be communication between these levels. How does the plant receive and respond to environmental inputs or "signals"? What communication is inside the plant to adjust growth and development in response to the environment? The answer lies in an understanding of plant hormones.

Definition:

Plant hormones are small organic compounds that influence physiological responses to environmental stimuli at very low concentrations (generally less that 10-7 M). Hormones are not directly involved in metabolic or developmental processes but they act at low concentrations to modify those processes.

Plant hormones are used extensively in agriculture, horticulture, and biotechnology to modify plant growth and development.

Hormones regulate or influence a range of cellular and physiological processes, including


    • Cell Division

    • Cell Enlargement

    • Cell Differentiation

    • Flowering

    • Fruit Ripening

    • Movement (tropisms)

    • Seed Dormancy

    • Seed Germination

    • Senescence

    • Leaf Abscission

    • Stomatal Conductance

Not all researchers agree that the term "hormone" should be applied to plants. Plants do not have a circulatory system and therefore hormone action in plants is fundamentally different from hormone action in animals. Many plant biologists use the term "plant growth regulator" instead of "hormone" to indicate this fact. The table below summarizes some of the differences between plant and animal hormones.

Plant Hormones

Animal Hormones

  1. Small molecules only

  2. Produced throughout the plant

  3. Mainly local targets (nearby cells and tissues)

  4. Effects vary depending on interaction with other hormones

  5. "Decentralized" regulation

  1. Peptides/proteins and/or small molecules

  2. Produced in specialized "glands"

  3. Distant targets ("action at a distance")

  4. Specific effects

  5. Regulation by central nervous system

Broadly speaking, the mechanism by which hormones act at the cellular level is similar in plants and animals. In both cases, the hormone must first bind to a protein receptor, either on the cell surface or inside the cell. This activates a signal transduction pathway, which amplifies the signal and leads to changes in enzyme activities, ion gradients, gene expression, and other physiological responses.



Five classes of plant hormones are recognized.

    1. Auxins

    2. Cytokinins

    3. Gibberellins

    4. Abscisic Acid

    5. Ethylene

Other "hormone-like" substances produced by plants include

    • Polyamines

    • Jasmonates

    • Salicylic acid

    • Brassinosteroids

    • Florigens

    • Phytochrome (photoreceptor)

    • Nitric oxide?

Auxins

  • Name from the Greek work auxein which means to "increase" or "augment"

  • First plant hormone discovered

    1. Phototropism experiments of Charles and Francis Darwin using oat coleoptiles

    2. Auxin eventually isolated by Frits Went

  • Auxins are produced primarily in shoot tips (shoot apical meristem) and growing leaves and fruits.

  • Auxins regulate two important processes in plant growth: phototropism (response to light) and gravitropism (response to gravity)

  • Auxins promote stem growth by stimulating cell elongation

  • Auxins control vascular differentiation of xylem and phloem

  • Auxins stimulate lateral root growth and root initiation on stem cuttings

  • Auxins move through the plant by "polar transport"

- Unidirectional movement down the stem through parenchyma cells
- Auxin apparently does not travel through the vascular tissue

  • Auxins inhibit lateral bud sprouting. This is called apical dominance

  • Indole-3-acetic acid (IAA) is the natural auxin

  • IAA is derived from the amino acid tryptophan

  • Several synthetic auxins have related structures

    1. napthalene acetic acid (NAA) (controls fruit set and sucker growth)

    2. indole butyric acid (Rootone)

    3. 2,4-D (herbicide, causes uncoordinated growth in broad-leaved weeds)


Cytokinins

  • Produced mainly in roots; travels through the xylem

  • Derived from the nucleotide adenine

    1. Synthetic cytokinins include benzyladenine and kinetin

    2. These growth stimulators are used extensively in plant tissue culture and are therefore important in biotechnology applications

  • Promote cell division ("cytokinesis")

  • Stimulate lateral bud growth

- determined by relative concentrations of auxin and cytokinin

Gibberellins

  • Largest group of hormones, over 70 known gibberellins

  • First isolated from a fungus (Gibberella fujikori)

- cause of "foolish seedling"

  • Derived from the terpenoid pathway

  • Produced in embryonic tissues (meristems)

  • Promotes stem elongation

    • Many "dwarf" plants are genetic mutants deficient in gibberellin synthesis

  • Enhances the effects of auxin

  • Stimulates germination in buds and seeds

  • Used commercially to break dormancy

  • Example: Germination in wheat seeds

    1. Seed takes up water

    2. Embryo produces GA

    3. GA diffuses to aleurone layer (surrounding endosperm)

    4. Aleurone produces amylase

    5. Amylase diffuses to endosperm and breaks down starch to glucose

    6. Glucose feeds growing embyro



Abscisic Acid

  • Synthesized in plastids from carotenoids

- Derived from terpenoid pathway

  • Produced in leaves, stems, and green fruits

  • Causes stomatal closure during water stress

  • Promotes dormancy in seeds and buds



Ethylene

  • Gaseous Hormone

  • Formed from the amino acid methione

- reaction involves cyclized intermediate 1-aminocyclopropane-1-carboxylic acid (ACC)

Ethephon is a commercial fruit ripener that breaks down to ethylene inside plant tissues



1   2   3   4   5


The database is protected by copyright ©sckool.org 2016
send message

    Main page