Healthy Black Jack Plants become sick within days of being moved to the Flower Room

[Dagmar]

I had two beautiful, healthy Black Jack plants that I moved into the flower room just under two weeks ago. Almost immediately lower leaves on the plants began to yellow and develop brown spots. It looks like what is described as a manganese deficiency but I use Fox Farms trio of nutrients; Grow Big, Big Bloom, and Tiger Bloom. I’ve heard that Black Jack is sensitive to nutrients and should only be given half the recommended dose, which seemed to work great in veg. I’m growing under CFLs for both veg and flower. The plants were under four 42 watt Daylight CFLs in Veg and are now under six 40 watt and six 24 watt Soft White CFLs. Can anyone help me understand what’s happen and how to fix it?

I’m a fairly new grower with two previous grows under my belt. The previous grows were of plants from unknown origins but they had similar problems with leaf loss. Even though they made it to harvest, the yield, I’m sure, was significantly reduced (between 1 and 1.4 ounces per plant).

[9fingerleafs]

I'm having a similar situation. I think is due the cfls. Not much light reaches the lower leafs and the plant sacrifice those. retrieving mobile nutrients and sending them up. If the leaf gets too ugly its better to remove it. Nothing wrong with your plant

also leafs die naturally at a calmed rate. nobody has ever grow a plant that didn't loose some leafs 😉

[Royal Nugs]

Need more info... pictures would help immensely.

Are there environmental differences with your veg room vs flower room? How long were they in veg before you moved them? Soil i'm guessing? Maybe coco? Are you changing the feeding regiment? Following fox farm nutrient chart?

[Beach_Town_Brit]

Are you using filtered or RO water? I've found that my plants need a boost of CalMag when I move them into flower (I use filtered water). As long as your bud formation and/or flowering stretch looks fine I wouldn't worry about losing older lower leaves ... I take it as a sign that the plant is shifting its focus to flowering and cannibalizing older veg growth.

1-1.5 ounces under CFL seems like a reasonable yield to me if that's dried and manicured bud. Especially if you're using smaller pots, like 2 gal pots.

I think I agree with 9fingerleafs 's supposition about CFLs. I veg under CFLs before moving to LEDs for flowering and I often find plants (especially bushy indica looking plants) drop their lower fan leaves in early flower in disconcerting looking ways. It seems to make sense that those lower leaves were already light neglected and the move into flowering pushes the plant to cannibalize them to focus on the new growth cycle.

[Dagmar]

The biggest environmental change is really just the obvious; Veg lighting 18/6 with Daylight CFLs and Flower lighting 12/12 with Soft White CFLs. The temp is between 77-80 degrees for both flower and veg with 39-42% humidity in flower and slightly higher in veg. The medium is soil and I change nutrients between veg and flower. I use tap water that is properly PHed.
Thanks to all for you feedback!

[Royal Nugs]

I think she's telling you she needs a haircut...

I think she looks great. Like the others said, the underside gets little to no light. The plant senses this and diverts its efforts to leaves that are photosynthesising. Nebula has a great section on trimming. Lollipop it up!

[9fingerleafs]

Also you might wanna use all the cfls you can to flower. And the soft withe (6500k) promotes growth and the daylight (2700k) promotes flowering

[Dagmar]

I think you got part of that backwards and according to an article by Nebula Haze: 40 W (6500k) Daylight for Veg and 42 W (2700k) Soft Shite for Flower.....Right?

[NebulaHaze]

Definitely use every CFL you have during the flowering stage for the best results! You both got the numbers right: 6500k promotes vegetative growth, and 2700k (soft white) promotes flowering. It's weird how they label CFLs because I've seen "bright white" and "daylight" used interchangeably with 5000k and 6500k bulbs, so it's best to go by the numbers if you can That being said, it's better to get more overall watts than stick with the right spectrum when it comes to making buds, which is why it's good to use all your bulbs in the flowering stage. A flowering plants wants all the light it can get, and isn't necessarily that picky!

[9fingerleafs]

Thanks nebula. You always have the perfect way to explain everything

[9fingerleafs]

Hahaha yes. I just realized I got it wrong. sorry I actually don't know how you call them in your country . In my country they are called blue and red. But the kelvins are the same. 6500 for veg and 2700 for flower