Plant Processes Plant Science

Trivia  What is the fastest growing organism on earth?  The Giant Kelp algea (Macrocystis pyrifera) is the fastest growing organism on earth and can grow at a rate of 70cm (two feet) a day. Sciensational.com

Plant Processes  Photosynthesis  Mixes light, water, and carbon dioxide in the presence of chlorophyll to produce sugar and oxygen  Respiration  Combines sugars and oxygen to give off water and heat  Transpiration  Loss of water through the leaves or stems  Causes wilting when soil is dry

Photosynthesis  X1o X1o  Process by which Carbon Dioxide and Water in the presence of Light are converted to Sugar and Oxygen  Takes place in the Chloroplasts  Carbon Dioxide + Water + Light + Chlorophyll = Glucose (sugar) + Oxygen  6CO2 + 6H2O + Light + chlorophyll = C6H12O6 + 6O2

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Respiration  The process of metabolizing (burning) sugars to yield energy for growth, reproduction, and other life processes.  Takes place mostly at night  Due to over-watering and poor soil drainage, roots often die due to not being able to take in oxygen  Plants give off more oxygen than they use

Transpiration  Release of water vapor from plants. Most transpiration occurs through the stomates of plants on the underside of the leaves.  Air also passes in and out during this process.  Process is used to cool or maintain heat within the plant.

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Nutrient Needs  All plants need certain nutrients to survive  Macro-nutirents- needed in large quantity  Micro-nutrients- needed in smaller quantities

Macronutrients  Expressed as N-P-K, as a % of of weight  N- Nitrogen  P- Phosphorus  K- Potassium or Potash

Micronutrients  Ca (Calcium)  Mg (Magnesium)  S (Sulfur)  Fe (Iron)  B (Boron)  Mn (Manganese)  Cu (Copper)  Zn (Zinc)  Mo (Molybdenum)  Cl (Chlorine)

A way to remember  C HOPKNS CaFe Cl Mn Mo Cu Zn Mg  See Hopkins café closed Monday morning see you soon, Management.

Diseases  Powdery Mildew caused by a fungus Looks like a white powdery growth on the plant Botrytis Blight caused by a fungus Gray fuzzy growth Pythium dark brown, rotted roots Damping –Off caused by a fungus and kills seedlings

Insect Pests  Aphids- small green, round bodied insects  Excrete honey-dew  Cause yellow spots on leaves  Fungus gnats- thin, gray colored flies  Damage is caused by the larvae, which are white worms with a black head  Mealy bugs- oval shaped insects, covered with a white powder

Insect Pests  Spider Mites- small yellow/red, 8 legs  leave a web on the plant  Leave yellow spots and strings on the leaves  Thrips- very small insects, 2 pairs of wings  Transmit diseases between plants  Feed on leaves and petals  White Flies- white insects, 4 wings  Live on the underside of leaves  Cause yellow spots on leaves

Biological Control of Pests  Integrated Pest Management-  The use of other beneficial insects to control insects that are harmful to greenhouse crops  Example- The chalcidoid wasp is used as a control for whiteflies. It lays eggs in the pupa of whiteflies. The adult wasp emerges from the dead whitefly carcass and begins to look for more pupa to lay eggs in, which restarts the process.