AGRISCIENCE AND TECHNOLOGY PRODUCING PLANTS AGRISCIENCE AND TECHNOLOGY Modified by Georgia Agricultural Education Curriculum Office July, 2002

TWO TYPES OF CELL DIVISION MITOSIS - The number of cells in a plant increase as the cells divide. CELL CYCLE - This is the sequence of events that occur in a cell from one mitosis to the next.

THREE PHASES OF A CELL CYCLE Phase 1 : Interphase - Cell is growing and increasing in size. Phase 2 : Mitosis - Two nuclei are formed. Phase 3 : Cytokinesis - The original cell begins to split and make two cells.

TWO TYPES OF GROWTH IN PLANTS PRIMARY GROWTH - When a plant gets taller; sometimes referred to as “linear growth”. SECONDARY GROWTH - Increases the diameter of stems and roots. In a tree this would produce “annual rings”.

TYPES OF WOOD IN A TREE SAPWOOD - It is the xylem that is two to four years old. Color of sapwood is lighter or white. HEARTWOOD - Innermost xylem in a tree. Color is darker than sapwood.

WHY PLANTS GROW: HORMONES AUXIN - Controls stem growth and regulates fruit development. GIBBERELLINS - Affects stem and leaf growth, fruit development, flowering, cell division and other plant activities. CYTOKINS - Promote cell division.

WHY PLANTS GROW HORMONES (CONT.) ETHYLENE - Causes potato tubers to sprout, pineapples to flower, fruit to ripen and leaves to fall off plants. ABSCISIC ACID - Helps regulate plant functions and promotes hardiness. Also is responsible for dropping of leaves and fruit.

PHOTOSYNTHESIS Process by which plants make food. Major product of photosynthesis is sugar; known as glucose. Plants need the following for photosynthesis 1. Chlorophyll 2. Sunlight 3. Carbon Dioxide 4. Water Photosynthesis produces two products: oxygen and sugar

RESPIRATION Occurs in living cells when energy is burned. Waste products are given off - carbon dioxide and water. Respiration takes place in the dark

TRANSPIRATION Loss of water from a plant. Most water is lost through the leaves. A tree may transpire as much as 80 gallons of water in one day. Water goes out of leaves through stomata.

REASONS WHY PLANTS WILT DRY SOIL DAMAGE TO ROOT SYSTEM DISEASE TOO MUCH WATER TOO MUCH FERTLILIZER

WAYS TO AVOID TOO MUCH WATER LOSS AVOID DAMAGING ROOTS PLANT DROUGHT-TOLERANT SPECIES FALLOWING NO-TILL CULTURE MULCH TERRACING IRRIGATION

MAJOR PLANT NUTRIENTS NEEDED NITROGEN- Makes leaves healthy and green. PHOSPHORUS- Is needed for seed germination and stimulates flowering. POTASSIUM- Is needed for healthy plants and tolerant of changes in weather; also needed for seed and fruit size.

MAJOR NITROGEN FERTILIZERS Ammonium Nitrate - 33 % nitrogen Anhydrous Ammonia - 82% nitrogen Urea - 45 % nitrogen Sodium Nitrate - 16 % nitrogen ** Legume plants have the ability to manufacture their own nitrogen from the air and put it into nodules that grow on their roots.

FACTORS THAT AFFECTS THE KIND AND AMOUNT OF FERTILIZER TO USE The requirements of the crop that will be grown The nutrients available in the soil Existing soil pH Whether or not the soil is acidic or basic

STEPS IN SOIL TESTING SAMPLING - Collect at a depth of 4-6 inches at several places in a field. SAMPLE ANALYSIS - Determining the amount of nutrients needed. INTERPRETING RESULTS - Compare the test results to the needs of the crop to be grown.

TYPES OF FERTILIZER DRY FERTILIZER - Pellets or granules LIQUID FERTILIZER - Dissolved in water and sprayed on the soil.

NUMBERS ON A FERTILIZER BAG FIRST NUMBER - % Nitrogen (N) SECOND NUMBER - % Phosphorus (P205) THIRD NUMBER - % Potash (K20) *** A fertilizer bag that is 5-10-20 contains: 5 % Nitrogen 10 % Phosphorus 20 % Potash

TYPES OF FERTILIZER PLACEMENT Pre-planting Application - Before the crop is planted. Planting Application - Apply as the crop is being planted. Post-planting Application - Applied after the crop is up and growing; known as top dressing or side-dressing.

RULES TO FOLLOW WHEN APPLYING FERTILIZER Use recommended kind and amount. Apply fertilizer only when it is needed. Store fertilizer in dry places where nutrients won’t be lost Clean equipment after it is used. Wear protective clothing and wash after handling or using fertilizer.