Seedling Feed Rate Experiment

[Dave Coulier]

I decided to create this thread to detail my attempts to discern what the proper feed level is for seedlings and when to feed to begin feeding them. Prior to this, Ive found the norm is that many growers dont fertilize their seedlings until the cotyledons are yellowing, which could be 2 weeks+. I believe this to be incorrect in determining when to feed, so I decided to pop some seeds and do some experiments. Seedlings were given their first feeding on the 4th day of their lives.

Variety: For this experiment I used 15 seeds of a cross of Mr. Nice Shit x (Sams O.haze x Skunk) that I made. Its my third time growing out this variety so I had prior experience with what to expect.

After germination I had 14 seedlings. Seeing as I didn't want to short my control group I made sure it had 5 seedlings. The other two groups fed @ 160N, and 80N had 5 and 4 seedlings. These seedlings are also on 12/12 from day 1. At day 21 I'll call the experiment and post final results, pics, and thoughts.

MEDIA: Promix Bx w/bio-fungicide. Amended with 15% Axis Regular and Bioworks Rootshield Plus were my only amendments.

FERTILIZER:
The non-control seedlings were fertigated on a near daily basis using GH 3 Part Flora series, Agsil 16h and Sequestrene 138. The control received RO water only on nearly a daily basis.

Nutrient Analysis:
N (NO3-): 150
N (NH4+): 11.926
K: 187
P: 45
Mg: 16.90
Ca: 127.92
S: 5.59
Fe:3.058
Zn: 0.384
B: 0.756
Cu:0.256
Mo:0.205
Mn:1.279
Si:61
Na:0
Cl:0

Mg, and S are low, but we will see if there are any issues with that as we go along.

Lights: 6 54w HOT5. The lights are kept around 5 inches away early on, but you'll see in the pics its raised up much higher to allow for better photos.

Expected Results: I expect the plants fed @160ppm N will grow the fastest and have the greatest amount of development while the control group will show deficiencies within 2 weeks and be stunted with the 80N group likely somewhere in the middle.

I encourage everyone to chime in with expectations, or experiences of their own. Id like this thread to be helpful to as many people and more input will see us there.

Now the PICS!
*Note: The plants in the pics are labeled 150, and 75N. I only realized as I was preparing this post that my feed rates were actually 160, and 80N. Even better, imo. I will update with weekly pics so everyone can see the progression.


Day 1:

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[Dave Coulier]

I was thinking about when to show more pics. If you'll notice the date in the pics, then you know 21 days have passed since then. I already know the results of this little experiment. Would you guys want the results and pics immediately?

 

[Dave Coulier]

Well Ive decided to go ahead and provide some more pics for you curious but quiet folk. Enjoy the pics.

The first feeding was given on Day 4. Its too early at this point to see any differences between them. Things will get more interesting on upcoming updates.

Day 6:

 

[vostok]

Last time I bought seeds
they got free food with them
at least for 2-3 weeks
why screw with that?

 

[Dave Coulier]

Last time I bought seeds
they got free food with them
at least for 2-3 weeks
why screw with that?

You'd be surprised how much fuel really is in the tank of the cotyledons. Those leaves can provide the plant the jump start it needs, but pretty soon they run out of juice if not fertilized shortly after germination.

Future pic updates will updates provide a clearer picture. Stay tuned!

 

[gmanwho]

curious about the results myself.

Im also curious if the food regime may have any influence on sex ratios. While it wouldnt work with the control, but if you were to keep increasing the food according to the group.

example, feeding group "80 ppm" then going to 160ppm, then 320, then 640ppm. the 2nd feeding group "160ppm" then 320 then 640.

The determining point when to increase food would be when the first plant of any group shows signs of wanting more food. At that point the food would be doubled for all plants in both groups.

some thought as to why doing it this way is to watch the male female ratios. And overall development across the board.

for instance if one group says im hungry, could that have been enough stress to influence sex? therefore the lower feeding group had less females? or More females? or no rhyme or reason?

So many variables thou.... an as you said these plants are further along then just planted therefore the test would have to wait, unless u never increased food yet?

Looking forward to your results.....

bsafe

 

[Dave Coulier]

curious about the results myself.

Im also curious if the food regime may have any influence on sex ratios. While it wouldnt work with the control, but if you were to keep increasing the food according to the group.

example, feeding group "80 ppm" then going to 160ppm, then 320, then 640ppm. the 2nd feeding group "160ppm" then 320 then 640.

The determining point when to increase food would be when the first plant of any group shows signs of wanting more food. At that point the food would be doubled for all plants in both groups.

some thought as to why doing it this way is to watch the male female ratios. And overall development across the board.

for instance if one group says im hungry, could that have been enough stress to influence sex? therefore the lower feeding group had less females? or More females? or no rhyme or reason?

So many variables thou.... an as you said these plant are further along then just planted therefore the test would have to wait, unless u never increased food yet?

Looking forward to your results.....

bsafe

Its funny you mention sex expression possibly being affected by feed level. I had the same thought after I found 4 of 5 girls in one particular group at the end of the experiment. I wont ruin which group it was. That'll come later, but there could be a link between feed level and sex expression..

For the duration of the experiment the plants were fed an unchanging level of nutes. Either none, 80ppm, and 160ppm N.

Thanks for getting involved in the thread Gmanwho. You'll definitely want to stick around till the end results. Your curiousity will be rewarded. In fact I may throw up another photo update today. There are only 3 left photo updates remaining. Stay tuned all.

 

[Dave Coulier]

Well Ive gotten the latest batch of photos uploaded to my album, and I imagine you all would want to look at them now.

Day 11:

 

[Dave Coulier]

In these first 3 pics from Left to right is 160-80-Control. The last pic is 160 v Control.

Day 11:

 

[Dave Coulier]

3 Final shots from the 11th.

160 v Control:


80 v Control:


160 v 80:

 

[gmanwho]

FERTILIZER:
The non-control seedlings were fertigated on a near daily basis using GH 3 Part Flora series, Agsil 16h and Sequestrene 138. The control received RO water only on nearly a daily basis.

Nutrient Analysis:
N (NO3-): 150
N (NH4+): 11.926
K: 187
P: 45
Mg: 16.90
Ca: 127.92
S: 5.59
Fe:3.058
Zn: 0.384
B: 0.756
Cu:0.256
Mo:0.205
Mn:1.279
Si:61
Na:0
Cl:0

Mg, and S are low, but we will see if there are any issues with that as we go along.

So what was the ratio of each of the 3 part to equall that 80n 0r 160n? Mil per gallon of each GH part?

been using the GH micro/bloom lucas head etc.. ratios for some time. think on my past i always used 2mil micro/3 mil bloom per gal for seedlings. then up to 4/6, to 6/9 8/10.

bsafe.....

 

[Dave Coulier]

Here is the break down of ml/g of GH 3 Part Flora series.

Micro: 10.25ml/gallon
Gro: 6.75ml/gallon
Bloom: 2.25ml/gallon

I used HydroBuddy to formulate my nutrient mix. I love that software.

For the 80N solution I just took the 160N solution and diluted it by half.

Agsil 16h @1.46gr/gallon provides 61ppm Si & 37ppm K.

Sequestrene 138 @.032gr/gallon provides .5ppm Fe. Stock solutions are required here.

 

[Dave Coulier]

Day 14 Picture Update

Day 14 Picture Update

Day 14

The seedlings were two weeks old at this point. Its at this point, about 9-10 days after first fertilization, where we really start to see a significant difference between Control and the other two groups of fertilized seedlings.

There's only one week worth of photo updates to come. The next one will be delivered in two days. Enjoy these for now.

 

[Dave Coulier]

Day 21 Update

Day 21 Update

Day 21

We've officially reached the end of this little experiment. I said at the beginning of this thread that the plants with the highest feed rate are likely to be the fastest growing. It just doesn't make any sense that a plant given no food for two or 3 weeks of its life will thrive. People confuse cotyledons as a bank full of nutrients, but in reality they're enough for germination and unfolding of the first leaves, but after that nutrients need to be applied in quick order for vigorous growth.

If Cannabis seeds utilized hypogeal germination, then the cotyledons would be storage organs of nutrients, and there would be some truth to the myth of seedlings not needing food for 2+weeks, but that wasn't the case in this experiment of mine.

Break out the nutrients and get them ready to go from early on growers. Thanks to the results of this experiment I felt brave enough to feed the same 160ppm N mixture to 3 GN Thai Stick Seedlings on day 2 from germination. Anyone want to guess what happened?

Now for the stuff you all really want to see. The pics.

 

[Dave Coulier]

Continued..

Continued..

 

[Dave Coulier]

Which one here was fed nutrients?

It was also on day 21 that plants began showing sex under 12/12 Lighting. All of the plants fed 160N showed sex by days 21-23. With 4/5 being female. The plants fed 80N showed sex by days 24-28. With 3/4 being female. The control plants were so stunted, sex was impossible to determine. I culled them at this point and started some GN Thai Stick in their place.

 

[TheRealHash]

Its funny you mention sex expression possibly being affected by feed level. I had the same thought after I found 4 of 5 girls in one particular group at the end of the experiment. I wont ruin which group it was. That'll come later, but there could be a link between feed level and sex expression..

Q: Can I increase my odds of getting a male for breeding?

A:, No, gender is determined genetically.

...Cannabis gender is controlled genetically, end of story. This is not news, it's well documented in the scientific literature, I can test for gender as of the moment the individual pops through the shell and shows the first piece of true leaf using a PCR method of detection for specific genetic sequences.

Cannabis gender is controlled by an XY system of sexual determination, with the heterogametic sex (XY) being the staminate or male gender.

aridbud post up the results of your experiment, and the statistical methods you used to conform your results vs expected probabilities.

The rest is hearsay and is completely false.

-Chimera

... I've germinated many many thousands of seeds in my day and all the regular seeds statistically approach 50/50 males:females the more seeds you grow. When you grow smaller lots you 'think' you see things that you assume make the gender lean towards one direction or another, but as the population size grows the apparent 'effect' disappears. I've grown many sets of seeds and used genetic markers to screen for the presence of the Y chromosome and it is %100 percent concordant with gender outcome.

You can alter gender expression with ethylene blockers or by spraying males with ethephon, you can pull crazy stresses on plants and make them show as intersex, but that effect is transient and does not alter the gender. Gender is determined by genetics, as stated previously, not by environment. This has been discussed ad nauseum over a series of internet fora, including this one so I'm not going to rehash it all here.

You can lead a horse to water....

-Chimera

From- "Can I increase my odds of getting a male for breeding?" Thread

https://www.icmag.com/ic/showthread.php?t=279805

 

[Dave Coulier]

Thanks for the link Realhash, even though your a party pooper.

 

[VerdantGreen]

interesting stuff dave, thanks for the well executed comparison!

so my seedling mix is 'unferted' except for about 10% EWC

can you tell me what percentage of 'full strength' the 160 ppm feed is?

then i can try to convert it to the correct strength of basic 'organic grow' liquid feed.

i generally start at about quarter strength for seedlings and clones.

VG

 

[TheRealHash]

Use a PPM meter yo~

edit: oh nm I just remember some organic nutes won't read on a PPM reader