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 Used for hardening seedlings and rooted cuttings 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 costs Easy access to harvesting crops Disadvantages: Humid air into the house Chemical spray health hazard (use biological control)

Earlier Greenhouses Modern Greenhouses

2. Single-Span Greenhouses

Standard Single-Span Greenhouses

Ridge and Furrow Greenhouse

Environmental Controls Temperature Light (Intensity, Duration) Plant Nutrition Humidity 5. Carbon Dioxide Concentration 6. Insect and Disease Control

Pad and Fan Evaporative Cooling System

Lighting for Photosynthesis

Influence of Photoperiod on Flowering

Spectral Distribution of Various Lamps

Four Components of Soil Soil and Growing Media Four Components of Soil

Adjustment of Soil pH To raise soil pH To lower 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-)

Inorganic components 1. Soil Amendments Sand: low water-holding, low CEC, heavy, size varies used as inert medium Vermiculite: expanded mica mineral high water-holding, good CEC, high buffering Perlite: heated, popped volcanic rock (inert) very light, no CEC, no buffering or nutrient holding Calcined Clay: baked montmorlillonite clay, aggregate particles heavy, durable, high CEC Pumice: Crushed volcanic rock (inert) low water-holding, low CEC

Using Soil in Growing Media 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

Artificial Growing Media The UC Mixes Mix A: 100% sand + 0% peat Mix B: 75% sand + 25% peat Mix C: 50% sand + 50% peat Mix D: 25% sand + 75% peat Mix 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 vermiculite Mix B: 1 part sphagnum peat 1 part perlite Foliage Plant Mix: 2 parts sphagnum peat - All mixes contain base fertilizers - Standardized with reproducible results - Extensively used for greenhouse crops

Greenhouse Uses

Water-Holding Characteristics Influenced by Container Height

Fertilizer Application 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 Tomato Calcium Deficiency Right-Hydroponic tomatoes grown in the greenhouse, Left-Blossom end rot of tomato fruits induced by calcium (Ca++) deficiency

Purification of Water Reverse Osmosis (RO water) Filtration Reverse Osmosis (RO water) Distillation (DI water)

Fluctuation of CO2 Concentration Inside a Greenhouse in One Day