Par For Stages Of Growth - Mimumin Requirements

[hawkman]

something I found:
Proagation - 14 day ---- need at least 150-200 PAR
Vegation stage 12 = days ------ 200 -550 PAR (gradual increase)
Transition stage (preflower 3-7 days) 450-800 PAR
Flower stage (8-10 weeks) 700 - 800 PAR

 

[DGP]

I never worry about the actual light values. I use COB and Quantum panel LED systems and I dim my lights on young plants and then watch to see what they need and increase the intensity and decrease the distance until I see maximum growth response with out stress for too much light. The plant will tell you what it wants. Very strain dependent anyway so a rule of thumb is just a general thing anyway.

Dee

 

[hawkman]

I never worry about the actual light values. I use COB and Quantum panel LED systems and I dim my lights on young plants and then watch to see what they need and increase the intensity and decrease the distance until I see maximum growth response with out stress for too much light. The plant will tell you what it wants. Very strain dependent anyway so a rule of thumb is just a general thing anyway.

Dee

just posted this for general knowledge -

 

[DGP]

Got it. Interesting thing to think about though. I sometimes wish there was a way to read the plants precisely and know each day exactly what they need but it is indeed more of a mystery than that.

Dee

 

[Photobiotic]

To me,

The numbers help people who easily get overwhelmed by the many factors that go into successful growth.

Every strain (cultivar) is different and wants different amounts of each growth factor. I look at light like an engine. The more energy per area (truly volume, "footcandles"), the more potential of that plant to increase growth rate and size. So having a number as a refference point is helpful if you are still learning to speak the language of the plants!

In short, measurements can help a grower keep the environment from fluctuating the wrong way. They also allow a grower to plan his/her next upgrade or next grow space. The sun itself produces a range of PAR/day/year. Only with measurements can we more accurately mimic the intensity of the sun in its perfect timing!

Hope this was helpful.

 

[Grownsince95]

I think it's also worth noting that the "gradual increase" during veg is accomplished by the plant growing closer to the light source indoors unless you are seriously tying down or cropping. Outdoors this is accomplished by the movement of the planet towards the summer solstice.
If you start all your strains in the same spot at the same intensity, you have a control to measure their performance against. Then future runs can be adjusted accordingly. My first run with a new strain always has a big learning curve.