What Are The Optimal Ranges For VPD (vapor Pressure Deficit) And CO2 Supplementation In A Sealed Greenhouse Environment For A Specific Cultivar Of Cannabis, Such As 'Sour Diesel', During The 3rd Week Of Flowering, When Utilizing A Combination Of LED Grow Lights And Supplemental HPS Lighting, And How Might These Variables Impact The Plant's Ability To Uptake And Utilize Calcium And Magnesium From A Balanced Nutrient Solution?
To optimize the growing conditions for 'Sour Diesel' cannabis in a sealed greenhouse during the third week of flowering, using LED and HPS lighting, consider the following:
Optimal Ranges:
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VPD (Vapor Pressure Deficit): Maintain a VPD range of 1.5-2.5 kPa. This balance supports healthy transpiration, crucial for calcium uptake, without causing stress.
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CO2 Supplementation: Target CO2 levels between 1200-1400 ppm. This range enhances photosynthesis under high light intensity from LEDs and HPS, supporting robust growth and nutrient utilization.
Nutrient Uptake Considerations:
- Calcium: Ensure adequate transpiration by maintaining optimal VPD, as calcium uptake is passive and depends on water movement through the plant.
- Magnesium: Monitor CO2 levels and light intensity, as magnesium is actively transported and plays a key role in photosynthesis. Ensure sufficient Mg in the nutrient solution.
Additional Considerations:
- Temperature and Humidity: Balance these to maintain the VPD range, crucial for preventing stress and promoting healthy growth.
- Nutrient Solution Balance: Ensure pH levels optimize nutrient availability, particularly for magnesium, which can sometimes be limiting.
By adhering to these guidelines, you can create an environment that supports healthy growth, maximizes nutrient uptake, and promotes robust bud development in 'Sour Diesel' cannabis.