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Growing Media . Why soilless. Physical properties Aeration Drainage Water holding capacity Support Chemical properties. Media Mix. Annuals Fafard 3B, Pro-Gro GPX, Pro-Mix BX Foliage & Hanging Baskets Fafard 3B, Metro 400, Pro-Mix BX Seedling
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Why soilless • Physical properties • Aeration • Drainage • Water holding capacity • Support • Chemical properties
Media Mix • Annuals • Fafard 3B, Pro-Gro GPX, Pro-Mix BX • Foliage & Hanging Baskets • Fafard 3B, Metro 400, Pro-Mix BX • Seedling • Redi Earth, Fafard Fine Plug Mix, Premier Germination Mix • Rooted Cuttings • Metro 360, Fafard #2, Pro-Gro 200
Deficiency Crop Yield Visible Deficiency Symptoms Seen Nutrient Level
Adequacy 95% Crop Yield Nutrient Level
Excess Crop Yield Post-mortem! Nutrient Level
Media Samples ? Testing greenhouse media provides an assessment of the material to adequately provide plant nutrients and provide a good rooting environment, i.e. low salt content and adequate pH.
pH Drift 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 Alkaline Water pH “Optimum” Range NH4+ fertilizers Time
Preventing High pH (Future) • Avoid NO3- fertilizers • Acidify water from 5.8 to 5.1 • Reduce lime charge in substrate
Low pH Action Steps • Stop neutralizing alkalinity in water • Switch from NH4+ to NO3- • Apply flowable limestone products: • start with 1 quart per 100 gallons • mist solution off of foliage
Preventing Low pH (Future) • Avoid NH4+ fertilizers • Inject potassium bicarbonate: • start with 13.4 oz per 1,000 gal • supplies 1.0 meq/L alkalinity • supplies 39 ppm K • Increase lime charge in substrate
Electrical Conductivity • Fertility elements come in the form of charged salts such as potassium nitrate or calcium chloride. These salts are charged and hence can transmit electricity when in a sloution with water. The more salt, the more electricity can be conducted. EC meters measure electrical current which is directly affected by salt concentration!
How to Monitor • Sample plants with different requirements separately • pH: acidic vs basic • EC: high vs low • Randomly select plants • Select plants from interior of bench
Monitoring: the Key ... • Have a manageable plan • Consider monitor and managing to be your insurance policy
PourThru EC’s • Crops vary in requirements • Low: 1.0 - 2.6 mS/cm • begonia, cineraria, impatiens • Moderate: 2.0 - 3.5 mS/cm • Easter lily, geranium, kale • Heavy: 2.6 - 4.6 mS/cm • chrysanthemum, poinsettia
High EC Action Steps • Decrease fertilization rate • Decrease fertilization frequency • Leach
Low EC Action Steps • Increase fertilization rate • Increase fertilization frequency