can lack of light kill lower fan leaves?

U

username1234567

Active Member
hey all,

i have my nirvana northern lights autoflower at 5 weeks 3 days.

it's doing fine , hasn't started flowering yet but there is quite afew preflowers forming on the tips of the plant :)

fan leave problem: ( sorry i cant provide a pic, my camara is bust. )

two weeks ago my fan leaves on the lowest node, they went a diffrent shade of green / yellow / brown. a day later they fell off with a slight touch.

ever since then the fan leaves have been dying and falling off from the bottom of the plant upwards.

i have lost a total of 12 fan leaves from the bottom 6 nodes.
( also to add, some baby leaves from the branches of the bottom shoots have been falling off aswell, but they look healthy like the ones that are still connected at other places on the plant)

could a lack of light be causing this?
its under a 120w full spectrum light on 18hours a day.

any replies would be helpful
thank you.
 
zvuv

zvuv

Active Member
No.

That was the short answer. Light starvation will show as a healthy looking but very light yellow green. You can see this color in the new leaves appearing from the growing tips. Otherwise it has to be severely light starved to show these symptoms and it would show on the whole plant.


What you are describing (I would be much better if you post pix), can happen for a number of reasons,

Pot bound: This is the most common reason. Look for roots coming out of the bottom, or, my preferred method, slide the plant partway out of the pot. If you see roots circling around the sides, she is overdue.


Nitrogen deficiency: This happens because young plants are usually planted in low nutrient soil and then given little or no nutes. Better to have this problem than over fertilizing. In that case start nutes ramping up from a weak solution to the level recommended for that stage of the plant's growth. You can also foliar feed a stronger solution for quicker results.

Magnesium deficiency: I dont usually see this until mid flowering but it doesnt hurt to add some Epsom salts to your water and also to the foliar feed.

Overwatering: This also common and is more tricky to spot. If all the leaves are droopy but not wilted and possibly the lower leaves are yellowing and dying, it may be overwatering. Again, I carefully slide the plant out of the pot. If the bottom looks sodden then it's probably overwatering. I flush the plant with a strong solution of hydrogen peroxide (need to look up the dosage) then let her dry out to the point of wilting before watering again. From there, I give her only half the water, (with hydrogen peroxide), that she would normaly get and only water when I see she starts to droop.
 
Ringsixty

Ringsixty

Well-Known Member
Yep, lack of light can do this to your plant. Look @ some of the other post or search the web for CFL grows. You will see many designs with some sort of lower or side lighting to help get some light to the lower parts of the plant. Especially when using low Wattage lights that can't penetrate the canopy from above.

JMO
username1234567 said:
hey all,

i have my nirvana northern lights autoflower at 5 weeks 3 days.

it's doing fine , hasn't started flowering yet but there is quite afew preflowers forming on the tips of the plant :)

fan leave problem: ( sorry i cant provide a pic, my camara is bust. )

two weeks ago my fan leaves on the lowest node, they went a diffrent shade of green / yellow / brown. a day later they fell off with a slight touch.

ever since then the fan leaves have been dying and falling off from the bottom of the plant upwards.

i have lost a total of 12r since thenfrom the bottom 6 nodes.
( also to add, some babynce thenfrom the branches of the bottom shoots have been falling off aswell, but theyncook healthyncike the ones that are still connected at other places on the plant)

could a lack of light be causing this?
its under a 120w full spectrum light on 18hours a day.

any replies would be helpful
thank you.
Click to expand...
 
Ringsixty

Ringsixty

Well-Known Member
Yep, lack of light can do this to your plant. Look @ some of the other post or search the web for CFL grows. You will see many designs with some sort of lower or side lighting to help get some light to the lower parts of the plant. Especially when using low Wattage lights that can't penetrate the canopy from above.

JMO
username1234567 said:
hey all,

i have my nirvana northern lights autoflower at 5 weeks 3 days.

it's doing fine , hasn't started flowering yet but there is quite afew preflowers forming on the tips of the plant :)

fan leave problem: ( sorry i cant provide a pic, my camara is bust. )

two weeks ago my fan leaves on the lowest node, they went a diffrent shade of green / yellow / brown. a day later they fell off with a slight touch.

ever since then the fan leaves have been dying and falling off from the bottom of the plant upwards.

i have lost a total of 12r since thenfrom the bottom 6 nodes.
( also to add, some babynce thenfrom the branches of the bottom shoots have been falling off aswell, but theyncook healthyncike the ones that are still connected at other places on the plant)

could a lack of light be causing this?
its under a 120w full spectrum light on 18hours a day.

any replies would be helpful
thank you.
Click to expand...
 
Gastanker

Gastanker

Well-Known Member
Lack of light causes stretch. You are suffering from a nutrient deficiency - likely nitrogen. Nitrogen is mobile within the plant so as the new shoots need nitrogen it is pulled from the older lower leaves. Eventually when the lower leaves have given up a large enough portion of their nutrients they undergo a process called cessation where the leaves phloem and xylem (veins) close off and the leaf is shed.

This is perfectly normal late into flower but if it is occurring too early try adding some nutrients.
 
U

username1234567

Active Member
Thank you for all the replies guys :)

I am a newbie so could anyone surgest some kind of nutrients i should give my plant?
I have only been giving it a home made fertilzer so far, which is decomposed stinging nettles mixed with rain water.

Thanks again.
 
zvuv

zvuv

Active Member
I use Flora Nova Grow and the Bloom for the flowering phase. They are simple, cheap and work well. There are lots of choices, from simple to as complex as you like and you can also go organic making teas of blood meal, kelp etc.

I suggest something simple and reliable like the Flora Nova

But, if she is pot bound, adding nutes can give you new problems and if she is overwatered it could be fatal.
 
U

username1234567

Active Member
Today i went to a gardening store, i got some Miracle-gro all purpose nutes
its NPK is 24-8-16.
i got high in N because i expected a N deficiency.
i mixed 2ml with 4 liters of water and watered.

secondly i got a soil PH tester, after following its instructions i have found my PH is at 5,
can anyone tell me how i can increase it? would prefer if it involves household items.

thanks :)
 
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