yellowing leaves

[dorjewright]

First let me appologise for the flood of questions and a thank you for the responses.

I have 2 screens, a 3x4 under a 600/adjust a wing at 16 to 18" from the canopy - alls cool here. The other screen 4x6 is under a 1000 adjw on a mover at about 18 to 22". 18" over the green crack and 22" over the trainwrack. The trainwreck has a lot of yellowing leaves right under the light less so at the edge but still plenty. Hidden foliage is also a darker green. Seemed to become more pronounced after flipping (4 weeks ago). Green crack has yellowing on the older growth - new growth seems ok.
5 gal smart pots, roots organic soil, little bit of subcool's soil mix, Earth Juice complete line.
I'm thinking too much light? Temps at the canopy are kept at 80 + or - a few degrees. Humidity 40 or so.
I suppose I could of burned them when I tried to "adjust" the EJ ph. Bad move. But the yellowing being intensified in the center of the canopy makes me thing light stress. Maybe a combination. I've run out of height but I could use a 750 bulb.

 

[dorjewright]

I've decided to try a weak solution of peaceful valley 4-4-4 on 1 girl of each kind to see if there is any positive response compared to the others.

 

[hiboy]

I dont think you have light burn or such. Most likely an underdosing of nutrients. I dont have much time in dirt, so i'll bump ya up
hiboy

 

[dorjewright]

There is a little improvement in color to the ssh and ogk not so much to the tr and gc. Going to bump up my nutes.

 

[MMRC Grower]

Yeah.... Your soil mix sounds like its depleted of nutrients. Give them girls some food and quick!! Otherwise your not gonna yield nada!!

Some yellow fading is a good thing, but your only on week 4. You should feed em and feed em heavy for the next couple weeks, then easy off and start flushing.

 

[QuarterbackMo]

feed them harder and check your ph of your soil... If it's not underfeeding it's your ph.

 

[jyip]

DJwright, what happened with em? curious cuz i have some in week five in soil as well, which is new to me,,, and i wanted to see if it WAS underfeeding as peeps guessed, or something else, in the lines you thought, as light stress, or bleaching as I call it,,, I have had plants in the past that seemed to suffer from being close to my 1000 k hps, and they passed the hand test, but still were an issue to my grow at that time
right now my light is stationary btw, and is between 14 -20 inches depending on which plant cuz i have 15 of differing sizes

heres my opinion, the sativa strong strains get bleached easier than indica dom plants, the only exception was when i had white widow goin and they loved it,, and green crack is similiar to WW, so i think u gott find what strains like the light better,,, but only if they werent underfeed,,,

 

[dorjewright]

DJwright, what happened with em? curious cuz i have some in week five in soil as well, which is new to me,,, and i wanted to see if it WAS underfeeding as peeps guessed, or something else, in the lines you thought, as light stress, or bleaching as I call it,,, I have had plants in the past that seemed to suffer from being close to my 1000 k hps, and they passed the hand test, but still were an issue to my grow at that time
right now my light is stationary btw, and is between 14 -20 inches depending on which plant cuz i have 15 of differing sizes

heres my opinion, the sativa strong strains get bleached easier than indica dom plants, the only exception was when i had white widow goin and they loved it,, and green crack is similiar to WW, so i think u gott find what strains like the light better,,, but only if they werent underfeed,,,

There is not a short answer;but I've got some ideas. My girls were definitely underfeed. Stepped up to full amounts of recommended EJ each watering. Yellowing persisted (probably irreversible anyway) but I've got a very good crop anyway. I did run across a thread on rollitup or grasscitty "Uncle Bens plant stress thread". One stress being spraying with neem oil and a surfacant and the leaves turned various shades of yellow. UB though probably from the surfacant (+ light). That's my best guess since it happened right after my spraying, think I also may have had the lights on too - but can't remember for ssure.
Bleaching from light - TR leaves stayed greener where they were shaded and the green crack greener at the edges where light is less intense. Maybe there is some connection between underfeeding and light.
I position my lights so the coolest area is at least 5500 ftc and the highest is 7 or 8k, about 18" ( on a mover) for the 1000w light and 12 to 14 for the 600w.
Hope this helps.

 

[jyip]

thx man... n glad ur crop turned out fine 4 ya...