Problem: Lower leaves yellowing in a mottled pattern, doesn’t look like natural die off. Potassium or Magnesium deficiency? A couple of leaves higher up are also now starting to show faint yellow blotches.
Medium: Bio-bizz Light Mix with added perlite.
Feed/supplements: Bio-bizz Grow, Bloom and TopMax. CalMag
Water source: Tap, left to leach off chems for >24hrs, PHd to around 6.7
Strain/age: Auto Big Bud (free seed), 50 days from germination.
Climate: on 20/4 cycle, temps between 24 and 28C, RH between 40 and 55. Had a short heatwave a few weeks ago here where the temp went above 30C for a couple of days which I presume is the cause of some “taco-ing” of the upper leaves.
Light: Viparspectra V450 LED full spectrum, 14” from top of plant.
Not my first auto grow, but the first under the new light. Also the first where I’ve tried some LST.
Everything looked good and healthy (aside from the slight heat stress at the top) and was getting excited about the bud growth until about ten days ago when I noticed the yellow blotches on one of the lower leaves. Can’t seem to find any pics on the net that look exactly the same to identify a particular deficiency.
I wondered if it might be a nutrient lockout and maybe I should try flushing it but I’m aware this stresses the plant and I’m not sure I should do that at this late stage of the grow.
Any thoughts gratefully received.
Medium: Bio-bizz Light Mix with added perlite.
Feed/supplements: Bio-bizz Grow, Bloom and TopMax. CalMag
Water source: Tap, left to leach off chems for >24hrs, PHd to around 6.7
Strain/age: Auto Big Bud (free seed), 50 days from germination.
Climate: on 20/4 cycle, temps between 24 and 28C, RH between 40 and 55. Had a short heatwave a few weeks ago here where the temp went above 30C for a couple of days which I presume is the cause of some “taco-ing” of the upper leaves.
Light: Viparspectra V450 LED full spectrum, 14” from top of plant.
Not my first auto grow, but the first under the new light. Also the first where I’ve tried some LST.
Everything looked good and healthy (aside from the slight heat stress at the top) and was getting excited about the bud growth until about ten days ago when I noticed the yellow blotches on one of the lower leaves. Can’t seem to find any pics on the net that look exactly the same to identify a particular deficiency.
I wondered if it might be a nutrient lockout and maybe I should try flushing it but I’m aware this stresses the plant and I’m not sure I should do that at this late stage of the grow.
Any thoughts gratefully received.
- huh, weird pattern of yellowing, it's something in between N and P defc.,.. my bet is P because of the necrotic patch stared already, N tend to yellow out the whole leaf more.. both are mibile within the plant, getting drawn from older lower leaves first usually... some of this is normal for this stage, so nothing to sweat here so far,....
