Leaves aggressively browning and dying from the bottom up. Help Appreciated.
I think I'm going to lose my Durban Poison and I have no idea why.
First Ever Grow
35th day of Flower
Temperature set to 75 degrees
Humidity 60% (Adjusted down to 45% today)
Fertigating twice a day
60/40 Coco Perlite
Underfilled 5gallon Fabric Pots, probably 3.5 gallons
|Liq Koolbloom 1|
I'm growing Durban Poison and Blue Dream. I was using a really basic feeding schedule of just Calmag, Micro, Gro, and Bloom all through Veg. Once I hit 12/12 the bottom leaves started to die. First on my Blue Dream plant, and now especially on the Durban Poison.
I know some leaves yellow and die in late flower, but this is mid/early flower for both of these plants, and the Durban Poison has lost around 40% of its foliage. Also it just started to flower after like a month of 12/12, which I'm thinking is a sign it is stressed..
After two weeks in Flower I noticed I screwed up the new nute schedule I'd put them on and was underfeeding them severely. So then I overfed them by feeding according to the Gen Hydro website without worrying about EC. I did this for about a week and leaves kept browning and dying, so I came to this website and started following the directions. I've been running as close to the CocoforCannabis plan as possible for the last 2-3 weeks: I adjusted my feeding, started watching my EC (started with a goal of 1150, now adjusted down to 950) keeping runoff within 300 EC. Ph runoff always around 6.0-6.2. Nutes are always Phd between 5.8-6.2. Blue dream is now losing leaves slower, although they are still going, but the Durban Poison is losing a couple handfulls every day. Top growth consistently looks great on both, but Durban Poison dead leaves are getting too close to the canopy to not be concerned. When you see the pictures please note that I have not defoliated at all (probably should have) all the missing foliage at the bottom died. Also of note is these leaves are not really yellowing. Some of the new growth that isn't getting light is weak and yellow, but most of the death is just brown and crispy.
Any help/suggestions would be greatly appreciated.
Is it happening to leaves under direct light or just the lower stuff and middle that are shaded out? Lack of light will cause leaves to die off. If any leaves aren't getting sufficient light the will eventually die off.
950ec is kind of low for early to mid flower, I run mine around 1200-1600 depending on strain. New growth looks fine, I wouldn't be surprised if it was just lack of light to the affected areas, it happens with bushy plants. I wouldn't worry about run off pH, just what's going in.
How often are you fertigating? If you let the coco dry out it could cause similar issues and even root problems. Plants that struggle for water and or nutrients will show similar signs. You shouldn't let the coco get too dry.
Durban poison is a sativa landrace and on a 12/12 cycle could take a long time to flower. Strains originating closer to the equator are used to long days and short nights, it's often temperatures that induce flowering. I don't think it was because it was stressed rather it could use another hour or two of darkness to really initiate flowering.
Looks like it still has plenty of green but if it's getting closer to the canopy there could be an issue.
Happening virtually exclusively to lower and middle shaded out stuff. I've heard this happens with lightless leaves but this is so many of them.
Fertigating twice a day, not letting it get particularly dry, although I am running a heater and worrying about it concentrating salts.
Thanks for the extra darkness recommendation, I'll flip to 11/13.
Due to the nature of the location where leaves are seeing this issue and the top growth still looking relatively healthy. This will have to be a mobile nutrient. Which is basically any of the major macro nutrients. In particular nitrogen, phosphorus or potassium. Based on the images it might be phosphorus deficiency. But ohnestly it could be any of them and i suspect this is a issue with a combination of more than one element. Possibly due to underfeeding as you had yourself pointed out.
These issues can certainly delay the flowering response, which makes it more indicative of a mineral deficiency.
At this stage your best solution is to get the feeding on track. Use a dosage that is recommended on our sites or by suggested members and do a major nutrient flush to get things on point as soon as possible. This will hard reset the substrate to the desired concentration. It will take significant volume or concentration to shift the substrates concentration levels. Use the runoff as a guide. Making sure with future feeds that this does not drop too far from the feeding concentration. Do a pH check for safe measures. You wont be able to resolve any potential pH issues with coir (complicated topic) but if there is a problem, this will tell you. Below 4 or above 8 pH is outside the ideal range.
You will likely be hindered by this but you might be able to get some produce still out of this.
All the best.