4.00: Analyze the process of growth in horticultural plants Plant Processes 4.00: Analyze the process of growth in horticultural plants

Processes of plant growth Photosynthesis Respiration Absorption Transpiration Translocation Reproduction

Photosynthesis The food and manufacturing process in green plants that combines carbon dioxide and water in the presence of light to make sugar and oxygen. Formula: 6CO2+6H2O+672Kcal C6H12O6+6O2 Carbon Dioxide Light Energy Glucose Sugar Water Oxygen

Respiration The process through which plant leaves, stems and roots consume oxygen and give off carbon dioxide. Plants produce much more oxygen through photosynthesis than they use through respiration.

Absorption The process by which plant roots take in water and air

Transpiration The process by which plants lose water from leaves and stems through evaporation

Translocation The process by which food and nutrients are moved within a plant from one plant part to another

Reproduction The plant process that increases plant numbers usually by seeds

Osmosis 1. The process by which minerals enter the plant through cell walls. 2. The process by which water enters the plant through cell walls

Stages of Plant Growth Juvenile-when a plant first starts to grow from a seed Reproductive-when a plant produces flowers, seeds and fruits Dormant-when a plant rests or grows very little, if any

Cell Organelles Chloroplast - cells that contain stacks of chlorophyll, where photosynthesis takes place. Chlorophyll - green pigment responsible for food production in plants. Only located in plant cells

Phases of the asexual cycle Vegetative-growth and development of buds, roots, leaves and stems cell elongation-stage when cells enlarge differentiation-stage when cells specialize Reproductive or flowering-plant develops flower buds that will develop into flowers, fruits and seeds

Effects of Light, Moisture, Temperature and Nutrients on Plants

Light Photoperiodism-response of plants to different amounts of light regarding their flowering and reproduction cycles Necessary because of photosynthesis Not enough light causes long, slender, spindly stems Too much light will cause plants to dry out faster Phototropism is the tendency for plants to grow toward a light source.

Moisture Needed in large amounts because plant tissues are 90% water and water carries nutrients Not enough water causes wilting and stunted growth Too much water causes small root systems and drowning which is a result of air spaces in soil being filled with water

VS Temperature Needs vary depending on type of plants Either too high or too low will have adverse effects VS

Nutrients Essential for optimal plant conditions Has little effect on seed germination

Combining growth factors Ideal quantities and quality will give optimum plant growth Each has an effect on the other factors Unfavorable environmental conditions for plant growth causes diseases to be more severe in their damages to plants

Plant Propagation 4.02: Apply different methods of plant propagation as related to horticultural plant production

Propagation The multiplication of a kind or species. Reproduction of a species.

Sexual Propagation Propagation from seeds. Pollen is transferred from the anther to the stigma. Fertilization occurs and seeds are produced.

Germination Rates Percent of seeds that sprout 75 out of 100=75% Rate is affected by seed viability, temperature and moisture. Rates vary depending on plant and quality of seed.

Seeds Plant depth depends on the size of seeds larger seeds are planted deeper water small seeds from bottom by soaking Embryo Seed Coat Endosperm

Seedlings (small plants) Transplant when first true leaves appear Reduce humidity and water and make environment more like outside to “harden off” plants

Seeds to Seedlings

Advantages of Sexual Reproduction Fast way to get many plants Easy to do Economical

Disadvantages of Sexual Reproduction Some plants, especially hybrids, do not reproduce true to parents Some plants are difficult to propagate from seeds

Asexual Reproduction Uses growing plant parts other than seeds Types of asexual reproduction: cuttings layering division or separation budding grafting tissue culture

Rooting from Cuttings Rooting media should be about 4 inches deep Best time of day is early mornings because plants have more moisture Types of cuttings: stem leaf root

Stem Cuttings Using a small piece of stem to reproduce plants using hormones and dipping in fungicides help speed up rooting

Leaf cuttings Using small pieces of leaves to reproduce new plants from herbaceous plants vein must be cut

Gather all materials needed Stem Cuttings-Step 1 Gather all materials needed

Cut 3 to 4 inch shoot from stem tip Stem Cuttings-Step 2 Cut 3 to 4 inch shoot from stem tip

Remove lower leaves from the shoot Stem Cuttings-Step 3 Remove lower leaves from the shoot

Dip cut surface in rooting hormone Stem Cuttings-Step 4 Dip cut surface in rooting hormone

Thoroughly moisten rooting medium Stem Cuttings-Step 5 Thoroughly moisten rooting medium

Stick one or more cuttings in rooting media Stem Cuttings-Step 6 Stick one or more cuttings in rooting media

Stem Cuttings-Step 7 Cover with plastic wrap or place on a mist bench in a warm area away from direct sunlight.

Once rooted, cuttings can be separated carefully and transplanted Stem Cuttings-Step 8 Once rooted, cuttings can be separated carefully and transplanted

Root Cuttings Using small pieces of roots to reproduce plants should be three inches apart in rooting area

Layering Scarring a small area of stem to produce new plants air layering trench layering

Trench Layering

Division or Separation Cutting or pulling apart plant structures for reproduction bulbs corms rhizomes tubers runners stolons suckers

Bulbs Rhizome

Grafting Joining separate plant parts together so that they form a union and grow together to make one plant. Wedge Graft Approach Graft

Grafting Terms Scion-the piece of plant at the top of the graft Rootstock-the piece of the plant at the root or bottom of the graft

Methods of Grafting If the scion and rootstock are the same size wedge splice whip and tongue approach

Methods of Grafting If the scion is smaller than the rootstock cleft side notch bark inlay

Budding A form of grafting when a bud is used patch budding T-budding Chip Budding Chip Budding

How to perform T-budding Step 2 Step 4 Step 1 Step 3

Tissue Culture Using a small amount of plant tissue to grow in a sterile environment The most plants in a short time True to parent plant

Advantages of Asexual Production Plants mature in a shorter time Budding is faster than grafting In trench layering, a plant forms at each node on a covered stem Some plants do not produce viable seed New plants are the same as the parent plant

Disadvantages of Asexual Reproduction Some require special equipment and skills, such as grafting Cuttings detach plant parts from water and nutrient source Some plants are patented making propagation illegal

The Uses of Biotechnology in Horticulture

What is Biotechnology? The use of cells or components (parts) of cells to produce products or processes

Methods Tissue culture or micropropagation Cloning Genetic Engineering

Tissue Culture Uses terminal shoots or leaf buds in a sterile or aseptic environment on agar gel or other nutrient-growing media to produce thousands of identical plants

Cloning Genetically generating offspring from non-sexual tissue

Genetic Engineering Movement of genetic information in the form of genes from one cell to another cell to modify or change the genetic make-up

Benefits of Biotechnology Produce many identical plants in a short time Increase disease and insect resistance Increase tolerance to heat and cold Increase weed tolerance

Benefits of Biotechnology Increase tolerance to drought Improve environment Increase production Other genetic changes