HELP! Yellow/black on leaves - jack herer indoor soil grow - week 13 (6th week of flower)

[Pizzalover]

Hey hey! I hope everyone is keeping healthy during these uncertain times.

First grow ever, 4x Jack herer femenized.
It is week 13 of the grow, and they're in the 6th week of flower. I expect to harvest in 2-3 weeks.

Sadly in the last week, the first real issues have started. Some of the leaves, mostly on one of the four plants, have started to seriously discolour. I can't tell if it's disease or nutrients, please take a look. I've decided to remove the worst of the leaves to prevent transmission in the case that they are infected.

Please let me know what you think

 

[WeirdWiredWolf]

I don't have any earthshaking advice, but...do you see anything that could be insects? Any stems affected or just leaves?

 

[F10werChyld]

Has anything changed but the light schedule? Are you feeding something new?

 

[Pizzalover]

Nothing has changed except for the light cycle, and that was 5+ weeks ago. It is generally warmer where I live as we get into summer, so temperature or humidity might be the cause. The canopy is also much thicker now that it's flowering, so perhaps leaves lying on top of each other and poor airflow allowed a fungus to start? Either way, unless you think it's too late in the flower stage and going to ruin the grow, I'll chop off the bad leaves.

 

[SoOrbudgal]

When i grew a Jack Herer it was outdoors over 7ft tall thick colas very resin filled so sticky. Had a breeze daily did'nt worry much but when she did'nt finish i had to bend her over to fit in the green house and super crop all her side branches. I was new to this site then sorry wish i had a photo of her. They get huge and great harvest, yes it developed some bud rot on several long colas i just cut it out. She went over 12wks once flowering began in Aug. outdoors. I thinned her leaf and just pulled her apart best i could. I tried not to remove top leaf.

 

[OldManGrower]

It is possible that you spilled some watering solution on the upper leaves. The nutrient could have caused a burn, the water droplets can act as a lens causing light concentration on that spot which will burn the leaf or perhaps the top of the plant is too close to your lights.

 

[Pizzalover]

When i grew a Jack Herer it was outdoors over 7ft tall thick colas very resin filled so sticky. Had a breeze daily did'nt worry much but when she did'nt finish i had to bend her over to fit in the green house and super crop all her side branches. I was new to this site then sorry wish i had a photo of her. They get huge and great harvest, yes it developed some bud rot on several long colas i just cut it out. She went over 12wks once flowering began in Aug. outdoors. I thinned her leaf and just pulled her apart best i could. I tried not to remove top leaf.

LOL 7 FEET!? Sounds amazing. Thanks, will chop off the bad stuff

 

[Pizzalover]

It is possible that you spilled some watering solution on the upper leaves. The nutrient could have caused a burn, the water droplets can act as a lens causing light concentration on that spot which will burn the leaf or perhaps the top of the plant is too close to your lights.

I hope not because I am very careful about watering only the soil, but it's possible. Thanks for the advice.

 

[WeirdWiredWolf]

That was going to be my next suggestion. I use a pump sprayer for watering, and when I was using additive nutes I had to be careful about overspray. Could be just light burn as well.