scientific experiment showing root growth rate V photoperiod

http://www.plantroot.org/PDFarchive/2011/5_17.pdf
Credit to the plantroot.org site and the authors of this wonderful document.

This link is a pdf of a scientific analysis of root growth rates in relation to photo period.

It's highly worth a read.

A brief summary of the findings are this:
At the time lights go off(night time), a dramatic sudden drop happens in Root growth rates. The plant then gradually increases its root growth rate right up until morning (lights on) when a large spike in root growth rate happens. So if you imagine it on a graph, its starts off at the bottom at lights out and climbs upwards towars morning with a big morning peak.

Then about 1-2 hours after lights on, it has a gradual decrease in root growth rate all day long until shortly before lights out(evening time) when it starts to climb but then does its sudden night time drop again.

So all in all, the growth rate for Roots looks an upside down V. with the peak being shortly after morning. the lowest points being evening time in the 24hour cycle.

Really wasnt expecting that. I definitely would of thought it was the inverse.

Anyways, the report then goes on to show the root growth rate of the plant if switched to a 24 hour lights on period... wow within 48 hours, the lowest root growth rate is already higher than the peak growth rate when on a On/Off light cycle.
The plant still follows the same drop and climb rate cycle as it did before, but the dips get less and less, and the climbing always is higher. So eventually its a far higher growth rate on a 24 hour light on cycle.

The graph doesnt go on for more than about 112 hours after that, but it looks like the dips begin to become less and less and so do the climbs. I imagine it would even out in a fair bit.

After that report, i'm going to try my veg at 24 hours and see if i notice a huge difference after the first 96 hours.

Tt

Pretty cool. Please update here. I'm subbed. Can't wait to see your findings

Will do. I'm currentily having major life/death issues with fungus gnat larvae. (I think). Small little whitish bugs creeping around the root areas. My plants seem to be having a very had time. Major defenciency + burn symptoms, ph was fine and my food was adqeuate. So It took a while to find the feckers.

I've watered with gnat off at 1ml/L. Suppose to kill the eggs i believe, but it doesnt seem to be doing anyting to the living gnats in the soil... Hoping they die off. I'm really counting on the accelaerated root growth to out grow teh damage the gnats are causing. At the moment it seems to be a 50/50 chance.

Stable diurnal growth rhythms modulate root elongation of Arabidopsis thaliana.
I wonder if thale cress root development can be compared to cannabis root development.

So its been a week

The first few days showed normal enough growth. but the last few days they've really taken off.

I usually run 18/6 photo period but this 24/0 is definitely offering better growth.

It look like it took a couple of days for the plants to adjust to it. Some seemed a little ..disagreeable with the light schedule for the first 48 hours. They looked like they found it difficult.

Now they are growing rapidily. I will check thier root systems in another 3-4 days when they dry out a little. This will give me a look at what 11 days in 24/0 looks like for a root system.

I know my plants quite well so I should be able to tell if there is a difference in root growth.

My plants were suffering from fungus gnats and a bad PH soil when young, Potting them into the big pots and making the lights 24/0 has completelyed saved thier asses. I believe the root system outgrew the problems. I kept one plant in small pot and 18/6.. It looks ALOT worst. Its lime green and wilting with necrosis still occurring. All plants in bigger pots and 24/0 are lush/dark green with plenty of new growth.
Same food/treatments were applied to both.

From now on, I think i will stick with 24/0 for veg whilst i can still fit them under 1 light!