Unhappy buds right under the light

[cctt]

These buds are getting blasted with HPS and driven the hardest. They look like they can't quite handle it. Can anyone identify the issue?

Everywhere else on the plant looks beautiful.

 

[Max Frost]

Looks like heat stress to me! If they are right under the light, they're getting the highest temps! How close are you running your light? Is it air-cooled? I'd raise the light a bit and maybe rotate the plants around so these get a break from being right underneath the hottest part. Good luck! Best, -Max :wacky:

 

[cctt]

Looks like heat stress to me! If they are right under the light, they're getting the highest temps! How close are you running your light? Is it air-cooled? I'd raise the light a bit and maybe rotate the plants around so these get a break from being right underneath the hottest part. Good luck! Best, -Max :wacky:

The leaves pictured sit 20-24" from a 1000W HPS bulb in an air-cooled hood on a lightrail. My IR thermometer measures 76F leaf temperature. CO2 as at 1000ppm, as well.

Unfortunately I don't have the vertical space to raise the light any farther. Rotating is also a good idea but they're well-established into trellis that makes this impossible.

 

[Max Frost]

If that's the case with your distance and temps, you should be OK. Sounds like you're locked in and can't do much anyway except just try to ride it out. It may just be light stress then, but again...not much I know of you can do in that sitch.

 

[Capulator]

too much light. not all plants like to be blasted. I would raise the lights a couple feet if you can.

EDIT just saw you cant raise the light. Switch the bulb to a 600.

 

[Seamaiden]

These buds are getting blasted with HPS and driven the hardest. They look like they can't quite handle it. Can anyone identify the issue?
View attachment 357058 View attachment 357059
Everywhere else on the plant looks beautiful.

I've seen that in plants that were unable to photosynthesize sufficiently in relation to the amount of light they were getting. Rotating the plants, and raising the bulb are two solutions. Also, super-cropping is another solution if you don't want to raise the bulb.

 

[Max Frost]

Good suggestion Sea! A thought...would raising the CO2 ppms be helpful in this situation? If it were due to heat stress (and I still think I'm seeing some heat stress in that pic) the increased CO2 would likely help the plants deal with the elevated temps better. Would it also help anything in the situation of too much light intensity?

 

[Seamaiden]

Thanks Max. It doesn't look like heat stress to me, though. I haven't ever worked with manipulating CO2, so I don't feel comfortable trying to answer to that or including it in my equation.

 

[cctt]

I've seen that in plants that were unable to photosynthesize sufficiently in relation to the amount of light they were getting. Rotating the plants, and raising the bulb are two solutions. Also, super-cropping is another solution if you don't want to raise the bulb.

I've been thinking the same - and just wishing there was a way to help their metabolism keep up with the demand. I do push plants very hard sometimes!
This strain is crazy sativa. I was topping it 25 days (!) into flower and it didn't seem to flinch. I could raise the lights perhaps an extra foot if I removed the lightrails, but I think they're also helping achieve the same goal of reducing hot spots.

 

[ttystikk]

What is your nutrient strength? Water temps or soil? I think you may be running slightly Weak on your nutes and the plants directly under the light are just running out of feed faster than the others.

 

[Seamaiden]

I've been thinking the same - and just wishing there was a way to help their metabolism keep up with the demand. I do push plants very hard sometimes!
This strain is crazy sativa. I was topping it 25 days (!) into flower and it didn't seem to flinch. I could raise the lights perhaps an extra foot if I removed the lightrails, but I think they're also helping achieve the same goal of reducing hot spots.

Then just pinch the stem under those buds. They'll flop down at first, then right themselves. That's what I would do, solve the problem where it's occurring, especially if everyone else is happy.

 

[cctt]

What is your nutrient strength? Water temps or soil? I think you may be running slightly Weak on your nutes and the plants directly under the light are just running out of feed faster than the others.

They're getting 1.75 EC in a hybrid DTW coir/DWC system (which itself is a new experiment, so there could certainly be issues here). Runoff is closer to 2.2 EC. Water temps are near 70F. It's a hungry strain, and in the phase of its life where it needs the most, so I was thinking it may be a sort of deficiency.

 

[ttystikk]

They're getting 1.75 EC in a hybrid DTW coir/DWC system (which itself is a new experiment, so there could certainly be issues here). Runoff is closer to 2.2 EC. Water temps are near 70F. It's a hungry strain, and in the phase of its life where it needs the most, so I was thinking it may be a sort of deficiency.

What's your air temp and rh? CO²? These are important clues, as well.

 

[cctt]

What's your air temp and rh? CO²? These are important clues, as well.

During lights on the air ranges from 75F to 80F, RH ~60%. I'd prefer to lower the vpd a little but during the winter I have to protect surrounding (much cooler) space from being exposed to such high water content. CO2 is at 1000ppm.

 

[ttystikk]

I'm stumped. Everything is on point, near as I can tell from remote camera range...

 

[Seamaiden]

Then just pinch the stem under those buds. They'll flop down at first, then right themselves. That's what I would do, solve the problem where it's occurring, especially if everyone else is happy.

:cyclops:

Has always solved the problem for me. :nurse:

 

[xX Kid Twist Xx]

i had a similar situation happening right in the begining of flower couldnt raise lights either . the new growth is developing so fast that it dosent get time to build the protective coating on the leaves. if your bulb is dimable turn it down a bit once the stretch is done you should be ok. maybe try and cover the center plants with soemthing for a few hours?

 

[xX Kid Twist Xx]

are you adding any cal-mag looks like a little varigation going on in the 1st pic, i can see some leaves curling in on one side.

 

[cctt]

:cyclops:

Has always solved the problem for me. :nurse:

I like the idea. This room is so full of buds I can't really push down any branches without crowding out other ones right now though. Extensive netting is also holding everything in place. I've been going a bit crazy trying to maximize my use of light. I am a big fan of efficiency, but it does make it hard to change anything later. :banghead:

are you adding any cal-mag looks like a little varigation going on in the 1st pic, i can see some leaves curling in on one side.

I calculate 156 ppm Ca and 52 ppm Mg in my solution

 

[ttystikk]

I like the idea. This room is so full of buds I can't really push down any branches without crowding out other ones right now though. Extensive netting is also holding everything in place. I've been going a bit crazy trying to maximize my use of light. I am a big fan of efficiency, but it does make it hard to change anything later. :banghead:

I calculate 156 ppm Ca and 52 ppm Mg in my solution

I'm deep in the middle of a similar conundrum, but I think I left myself an out; my plants like to grow through my vertical trellis and then continue growing up and towards the light. Every day or so during stretch, I go in and pull them back through and lay them up against the trellis from the back side, where they start growing again. This has the effect of laying the plant out flat against the trellis screen and making it cover more surface area.

I'll let you know what happens when stretch stops and they start stacking, but I'm thinking it's going to be good...