What Deficiency Is This?

[trichcycler]

The first issue to address is your humidity, cleanliness, temperatures 24/7, and air flow. A plant will only grow to it's weakest resource. Mold and mildew present in any room is a strong indication that your atmosphere may be your weakest resource. After the known problem is addressed there's a better chance of proper diagnosis. good luck!

I have one plant in my garden, a Kosher Kush, that has some leaves that look exactly like Akeldama's, especially the pattern of the brown spots. I've had a little PM in my flower room, but none in veg where the KK is. That, and I started adding an organic fungicide once or twice while watering in veg. I feed this one exactly like I treat the others, so it must be something peculiar to this strain. So... what's the problem with our plants? 

I checked out the link about plant problems. Which brings on another question. Once in a while I'll have a strain or just one particular plant that will put out twisty leaves. The article indicates that that is from a ph that is too high. I was having a problem with that with my Sour Lifesaver plants. After adding more magnesium the problem went away, but I still occasionally have the problem with other strains and plants. Any input on this? 

[Norby]

Powdery mildew at 40% humidity?  Looks like a deficiency to me.  Are you using cal mag?  What kind of test are you using for ph runoff?  The red stems looks like p deficiency.  What nutes are you using and how often?  If your using ph water below 7 to flush and it's coming out 7 ph could be too hi.

[trichcycler]

Powdery mildew at 40% humidity? 

 

 

"Today I noticed a couple leaves had a white powdery substance on them"

 

I never seen a deficiency cause a white powdery substance on leaves.  maybe "that one time" humidity was checked with lights on, it was 40%?  lights off is when humidity issues are often seen. less heat, cooler temps generally

[Norby]

Quite right, I'd definitely check esp if there is less airflow and they are already stressed but I'd also check the underside of the buds for any sacs of bananas.  If powder is only over one or 2 leaves it could very well be pollen.  Need better pics or a better check to tell.

"Today I noticed a couple leaves had a white powdery substance on them"

 

I never seen a deficiency cause a white powdery substance on leaves.  maybe "that one time" humidity was checked with lights on, it was 40%?  lights off is when humidity issues are often seen. less heat, cooler temps generally

[Akeldama]

I highly doubt its mildew as I checked the plants the past two days and there isn't any on the leaves now. I just use the ph up/down kit by GH. For nutes I'm just using Floranova Bloom

[Letterhead954]

The first issue to address is your humidity, cleanliness, temperatures 24/7, and air flow. A plant will only grow to it's weakest resource. Mold and mildew present in any room is a strong indication that your atmosphere may be your weakest resource. After the known problem is addressed there's a better chance of proper diagnosis. good luck!

I haven't had PM since before this winter. I'm told it's due to lower temps. My lights on temps are around 77 and around 67 with lights off, sometimes going a little lower if it's really cold out. I have plenty of airflow, both intake into my rooms and in my rooms. What I'm wondering about is what's going on with my Kosher Kush, which seems to have the same problem as the op's. There is no PM problem in my veg room. The plant is growing well, but the large fan leaves keep looking like there's a deficiency somewhere. Calcium or magnesium maybe? They look very similar to the op's pics, especially with the dead spots all in a row on the one leaf. 

[pergamum362]

I just have a hard time believing pollen would collect on a leaf, its like dust, if released it would e blown all over the place.

[Akeldama]

I can just see a banana sack opening and the pollen just falling onto the leaf below it tho?

[Norby]

not if the fan isn't blowing on it.  When I let males go I put them under a florescent in another room and with no fan on them they drop a lot when they open. 

[Akeldama]

There is a fan blowing into the tent from the bottom tho. It was only on 2 out of 12 plants and I snipped those leaves and there hasn't been any more since then

[trichcycler]

the mold is ever present in most rooms. It takes a certain set of atmospheric conditions for it to thrive. Temps is one, but cold temps don't automatically cause the mold expression on plants, without a humidity issue, often going hand in hand though. I cool/heat my rooms to 75 24/7, regardless of outside temps, and never seen the mildew on plants. I aint the cleanest grow room around either, more like an indoor greenhouse here, but no molds, mites or issues of any kind so far.

I haven't had PM since before this winter. I'm told it's due to lower temps. My lights on temps are around 77 and around 67 with lights off, sometimes going a little lower if it's really cold out. I have plenty of airflow, both intake into my rooms and in my rooms. What I'm wondering about is what's going on with my Kosher Kush, which seems to have the same problem as the op's. There is no PM problem in my veg room. The plant is growing well, but the large fan leaves keep looking like there's a deficiency somewhere. Calcium or magnesium maybe? They look very similar to the op's pics, especially with the dead spots all in a row on the one leaf.