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Plant Propagation Facility
• Types of Structures
• Environmental Modifications
• Cultural Procedures
• Propagation Facility
• Recommendations
Propagation Structures
Propagation requires controlled environment: Light Temperature Moisture Gasses (CO2, O2)
Types of Propagation Facility
Cold Frames
Hotbeds
Greenhouses
Shade Houses
Cold Frames Semi-controlled environment
Used for hardening seedlings and rooted cuttings
Can also be used for vernalizing herbaceous perennials
Hotbeds
Small, low structures for minimum environmental control
Some bottom-heated: Use of electrical cables, hot water, stream- Heat from organic waste (manure, straw) was used earlier days
Possible problems:- Seedling damping-off (Pythium, Rhizoctonia)- Complete control of temperature difficult
Structural Designs of Greenhouse
1. Lean-to Greenhouses
2. Single Span Greenhouses - Even-span greenhouses
- Uneven-span greenhouses
- Arch or curvilinear greenhouses
3. Ridge-and-Furrow Greenhouses- Gutter connected multi-span greenhouses
1. Lean-to Greenhouses
Build against a side of an existing building
Advantages: Less heating costsEasy access to harvesting crops
Disadvantages: Humid air into the houseChemical spray health hazard (use biological control)
Earlier Greenhouses Modern Greenhouses
2. Single-Span Greenhouses
Standard Single-Span Greenhouses
Ridge and Furrow Greenhouse
Environmental Controls
1. Temperature 2. Light (Intensity, Duration)3. Plant Nutrition4. Humidity5. Carbon Dioxide Concentration6. Insect and Disease Control
Pad and Fan Evaporative Cooling System
Lighting for Photosynthesis
Influence of Photoperiod on Flowering
Spectral Distribution of Various Lamps
Soil and Growing Media
Four Components of Soil
Adjustment of Soil pH
• To raise soil pH– Ground limestone (CaCO3)– Dolomitic lime (mixture of CaCO3 + MgCO3)– Gypsum (CaSO4)
• To lower soil pH– Sulfur powder (S)– Aluminum sulfate [Al2(SO4)3]– Iron Sulfate (FeSO4)– For solution, use:
• Sulfuric Acid (H2SO4 ------------► 2H+ + SO4-2)
• Phosphoric Acid (H3PO4 ------------► 3H+ + PO4-3)
• Nitric Acid (HNO3 ------------► H+ + NO3-)
1. Soil Amendments
a. Inorganic componentsSand: low water-holding, low CEC, heavy, size varies
used as inert mediumVermiculite: expanded mica mineral
high water-holding, good CEC, high bufferingPerlite: heated, popped volcanic rock (inert)
very light, no CEC, no buffering or nutrient holdingCalcined Clay: baked montmorlillonite clay, aggregate
particlesheavy, durable, high CEC
Pumice: Crushed volcanic rock (inert)low water-holding, low CEC
Using Soil in Growing Media
a. Heavy Texture Soil Use: 1 part clay loam
2 parts organic matter 2 parts coarse aggregate
(amendments)b. Medium Texture Soil Use: 1 part silty loam
1 part organic matter 1 part coarse aggregate (amendments)
c. Light Texture Soil Use: 1 part sandy loam
1 part organic matter
Artificial Growing Mediaa. The UC Mixes Mix A: 100% sand + 0% peat
Mix B: 75% sand + 25% peatMix C: 50% sand + 50% peatMix D: 25% sand + 75% peatMix E: 0% sand + 100% peat
- All contain base fertilizers - Used mainly for nursery crops (more popular in California)
b. Cornell Mixes (Peat-Lite Mix, Soil-less Mix) Mix A: 1 part sphagnum peat
1 part vermiculiteMix B: 1 part sphagnum peat
1 part perliteFoliage Plant Mix:
2 parts sphagnum peat 1 part vermiculite 1 part perlite
- All mixes contain base fertilizers- Standardized with reproducible results- Extensively used for greenhouse crops
Greenhouse Uses
Water-Holding CharacteristicsInfluenced by Container Height
Fertilizer Application
1. Preplant Application-Lime, sulfur, superphosphate, gypsum, dolomite
2. Dry Application - Fertilizers with solubility <20 g/100 ml
- Top dressing- Do not apply lime with phosphorus
3. Liquid Feeding - Use soluble fertilizers
- Constant feeding vs intermittent feeding
Fertilizer Application
Blossom End Rot of TomatoCalcium Deficiency
Right-Hydroponic tomatoes grown in the greenhouse, Left-Blossom end rot of tomato fruits induced by calcium (Ca++) deficiency
Purification of Water
- Filtration
- Reverse Osmosis (RO water)
- Distillation (DI water)
Fluctuation of CO2 ConcentrationInside a Greenhouse in One Day