Photosynthesis • requires light • requires chlorophyll • requires CO2 • needs water • produces sugars (energy) • oxygen is released 6CO2 + 6H2O C6H1206 + O6
Respiration Unlike photosynthesis, respiration takes place at all times, day and night C6H1206 + O2 CO2 + H2O + Heat
Photosynthesis • Produces food • Releases oxygen • Occurs in all cells containing chlorophyll • Uses water • Uses carbon dioxide • Occurs in light • Respiration • Uses food for plant energy • Releases energy • Occurs in all cells • Uses oxygen • Produces water • Produces carbon dioxide • Occurs in light as well as dark
Transpiration The process by which plants lose water, primarily through stomata. The amount of water loss from a plant through transpiration depends on environmental factors such as temperature, humidity and air movement. Transpiration is also important in cooling plant parts through evaporation.
Guttation Occurs mainly at night due to root pressure.
Light Quantity - maximum during the summer and minimum during the winter and can be controlled by shade cloth. Quality - refers to the color or wavelength that reaches the plant. Duration - refers to the amount of time a plant is exposed to light.
Temperature Temperature is a factor in flower and fruit production such as chilling indexes needed for peach production. Plants will produce maximum growth when day temperatures are 10 to 15 degrees higher than night. Plants can be classified as either hardy or nonhardy depending on their ability to withstand cold temperatures.
Plant Nutrition • 16 Essential Elements • Necessary for a plant to complete its life cycle • Must play a specific role in the plant’s life • No other element can substitute for it
Plant Nutrition Primary C H O N P K Ca Mg S Micronutrients Secondary B Cu Cl Mn Zn Fe Mo C HOPKNS CaFe Mg B Mn CuZn MoCl
C - CarbonH - HydrogenO - Oxygen P - PhosphorousK - PotassiumN - Nitrogen Ca - CalciumMg - MagnesiumS - Sulfur B - BoronCu - CopperCl - ChlorineMn - ManganeseZn - ZincFe - IronMo - Molybdenum Derived from the atmosphere and are the main building blocks of the plant. } Derived mainly through fertili-zation and mineral release from soil degradation. Plant growth. } Primary Nutrients } Derived mainly through fertilization, liming and mineral release from soil degradation. Important in enzymes and protein formation. Secondary Nutrients Derived mainly from natural occurrence, weathered rock and through fertilization. Needed in less quantity than other elements and are important in various enzyme activities. } Micronutrient Nutrients
Nutrient Absorption Active process - Oxygen must be present • Mass Flow • Root Intercept • Diffusion
Factors Inhibiting Nutrient Uptake Soil Aeration Nutrient Availability Soil Temperature Type of Plant Soil Moisture Effects of Other Nutrient Soil pH Solubility of Nutrient