Can bottom leaves to start yellowing because of lack of light?

[Howard Marks]

Hi

I have for plants, they are in their 5th week veg stage and 2 of my plants shows a little yellowing of the bottom leaves, nothing to dramatic though.
I fertilize them with biogrow from biobizz and upped the dose a little bit but this dosent fixed my problem.

My PH is between 6.5 and 7, i dont water the plants just when the pots are light and soil is drying off, when i water i water slowly till i have some run off.

My ferts are 2 years old and thought that they are no any longer good but then i thought about the light too, i have 250w MH that dosent penetrate to good the plants, definitively the light on lover leaves barely gets. So my question, could be the lights the problem of the yellowing or the nutrients are old?
Thanks for the help!!

 

[macncheese]

Same thing has happened to me about seven weeks into veg. I've had two shaded leaves on the first node turn completely yellow. I read another thread here where the poster says that the low light leaves where "consumed" by the plant first.

 

[Crusader Rabbit]

What you're observing is normal growth patterns.

 

[nukklehead]

your girl is having her 1st period.. time to turn her into a beautifull woman... lol

 

[Howard Marks]

Thanks guys for the feedbacks. Yeah friday i'll turn the lights to 12/12. They will be 6 weeks, they are very developed and i could have been switching to flower earlier but there was no rush.

 

[medicalmj]

Plants will also take what it needs from older leaves to put it into new growth. The lack of light will make the plant deem that the leaf is no longer a site of an efficient photon receptor. So it will slower fade away as the plant uses the leaf's stores. You can either spread your plant out to allow more light and perhaps a foliar spray, or let it ride. I wouldn't pluck the leaf unless it is diseased.

 

[Howard Marks]

Ok, so today i have managed to take some pics of my plants, they are 6 weeks old, from tomorrow they will go into flower schedule.

Beside the yellow leaves i have spotted today some brown spot on one of my plants.

Is this nutrient burn or other deficiency? I thought about nute burn because i upped the nuts because of my yellow leaves but after seeing some other pics in the forum i think its some other issue.
Can anyone help me out wit an answer? Thanks!!

Overall Health


Brown spots


Yellowing leaves

 

[chuewy]

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[Hash Zeppelin]

Plants will also take what it needs from older leaves to put it into new growth. The lack of light will make the plant deem that the leaf is no longer a site of an efficient photon receptor. So it will slower fade away as the plant uses the leaf's stores. You can either spread your plant out to allow more light and perhaps a foliar spray, or let it ride. I wouldn't pluck the leaf unless it is diseased.

This is solid info, I do one thing different though. I pluck the leaf at 75 percent yellow to keep my under canopy clean.

 

[Hammerhead]

if the leaf is complety yellow you can pull them off. there of now use at this point.

 

[medicalmj]

if the leaf is complety yellow you can pull them off. there of now use at this point.

Hash definitely brings up a good point about determining a point of diminishing returns...you'll get a feel for when to pluck.

 

[Crusader Rabbit]

Hash definitely brings up a good point about determining a point of diminishing returns...you'll get a feel for when to pluck.

How many times have I pondered whether to pluck a leaf, left it alone, then found it laying sodden in the bottom of the flood tray a day later?

 

[Hammerhead]

I Prune green leaves as well. Depends on what im trying to do with the plant.

 

[Canniwhatsis]

Personally I wander thru and give the yellow leaves a light tug, If they fall right off they get tossed,... if not I leave them until my next pass.


I do this both in vege and flower.



The way I see it, if the plant doesn't WANT to let go of the leaf, it's still serving a purpose, and should remain attached.

 

[Canniwhatsis]

I Prune green leaves as well. Depends on what im trying to do with the plant.

I guess I do as well on occasion,..... if by pruning green leaves you mean topping to promote branch growth

Again tho it depends on what I'm trying to do with the plant.

 

[Howard Marks]

I see guys, thanks for all your feedback, very useful. What about the 2nd picture? The brown spots on that leaf, is it some deficiency or a little nut burn from raised doses of N. I was a little concerned about the yellowing of the leaves so my last 2 feedings were a bit high.
Im using organic feeding from Biobizz, i use biogrow and now that im going into flower i will use biobloom too.
I also changed the lights, im using now a 400w HPS instead the 250w MH but again, im concerned about those brown spots that i seen on some leaves. I worry to much? ))

 

[Dkgrower]

Oberservations have lead me to think is 99% due to lack off Nitrogen -

In general u plants look healthy but if u get yellowing of leafs from the bottom up, in mid flower u should up the Nitrogen in u feed program