Black discoloration

[khoyle]

Hey guys. I have a gorilla glue auto with some dark and faded spots on the top sugar leaves. I'm on day 78 (started counting at germination) and I haven't given any nutrients for a week and a half since I anticipate harvesting soon. Can you start a flush too early? The dispensary I bought my seeds from says 70-75 days from seed to harvest for this strain but I still have quite a few white pistils on the buds. They just don't look ready.

Anyhow, I have noticed that some leaves on only one of the plants (I have 4) have faded and dark spots on some of the topmost sugar leaves. I have some pics of the leaves as seen by the naked eye and also some I took with the microscope. Does anyone know what is going on with it?

 

[Sativa1970]

First, always take the claims from seed vendors with a grain of salt. Generally they fudge the time by week or two. They "forget" to start counting until the first true leaves and stop at the earliest possible harvest. Looks like one more week to me.
Second, yes you can flush too early. The plant need nutrients to develop, fight off insects and funguses. When you flush it forces the plant to use it's last reserves, stored in the leaves to finish. Flushing too soon will starve the plant when it is trying to make the stuff you have been waiting for. If you are in hydro (the only time flushing works) you can defoliate and flush for a couple days before harvest and be good.
Third, the first pic is too out of focus to tell much. The yellowing could be magnesium deficiency,, maybe. but it doesn't look like nutrient deficiency is causing the dark spots. That looks more like moisture issue. Since it is only one plant what is different? Is that one plant not getting the fresh air flow from fans compared to the others?

 

[jaybirdz]

What light are you using and how long is it on per day? Are you using any type of foliar spray?

 

[khoyle]

I don't think that one plant is different. I treat them all the same and rotate them under the lights every so often. I have a tower fan in the tent, but pointed at the tent wall rather than the plants. I also have a small fan hanging above the plants. I've had the humidity at 40-45 for a week and a half now. Before that it was around 50-60%.

I may have the plants too close together. Pics below of the set up. All in all, I think they look really good for my first grow. The plants overall look healthy and seem to be progressing like they should. I've been super vigilant at trying to prevent any kind of mold so I really hope that's not the problem.

I also added another pictures of the leaves I cut off. Sorry about the blurry first one.

 

[khoyle]

What light are you using and how long is it on per day? Are you using any type of foliar spray?

For these plants I have a Viparspectra p1500. I haven't used any foliar spray in weeks, and then it was just epsom salt.

 

[khoyle]

First, always take the claims from seed vendors with a grain of salt. Generally they fudge the time by week or two. They "forget" to start counting until the first true leaves and stop at the earliest possible harvest. Looks like one more week to me.
Second, yes you can flush too early. The plant need nutrients to develop, fight off insects and funguses. When you flush it forces the plant to use it's last reserves, stored in the leaves to finish. Flushing too soon will starve the plant when it is trying to make the stuff you have been waiting for. If you are in hydro (the only time flushing works) you can defoliate and flush for a couple days before harvest and be good.
Third, the first pic is too out of focus to tell much. The yellowing could be magnesium deficiency,, maybe. but it doesn't look like nutrient deficiency is causing the dark spots. That looks more like moisture issue. Since it is only one plant what is different? Is that one plant not getting the fresh air flow from fans compared to the others?

I put a response in the thread below. Idk why I didn't hit the reply button.

 

[khoyle]

What light are you using and how long is it on per day? Are you using any type of foliar spray?

Sorry - 18/6

 

[Sativa1970]

Pictures and details help a lot. Plants look good, and for a first grow, impressive!

So your humidity, air circulation, no foliar spray would rule out molds in my opinion.

The yellowing and most likely the brown is a nutrient deficiency. Since you have been flushing for almost 2 weeks now I would say the nutrient you are lacking is all. The plant is cannibalizing's stored nutrients in the leaves to feed the flowers. You may want to give her a 1/4-1/2 strength nute feed to help the flowers. If you want more of a heady high from cloudy trichomes you may be able to just let it run. If you want more of a body high from amber trichomes and maybe some plumping I would give her a snack.

Flushing is one of those topics that there is no correct answer and it can get heated. You will get always flush, never flush, only do it this way or that way. Every grow is different so you have to find what works for you and your grow. Your plant is telling you it is hungry so it is your call. I would feed 1/2 nute then flush the next two times watering but it is your call.

 

[Sativa1970]

Just scrolled over to close this tab an saw you are running 18/6 and I forgot this was an auto. Light breaks down chlorophyll constantly to yellow then brown. The plant is constantly replacing chlorophyll made from carbon, H2O, Nitrogen and mag. Light degradation without ingredients to replenish.