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