Autoflower yellow leaves at week 7

[Tom81]

Hi,

My autoflower plant is in week 7, roughly about a week ago, the older bigger leaves started to turn evenly yellow, now the upper smaller ones seem to follow slowly.
Any ideas? Mg deficiency?

Also, about 50% of the pistils already turned orange. Is that normal at week 7?

 

[Catfish22]

We need to know what setup you are running. Grow medium, strain, nutrients, pH, RH, it is hard to trouble shoot with just symptoms.

 

[Tom81]

thanks for your message.
it's soil with 30% perlite, Dutch Passion CBD Auto White Widow, cactus feed 4-6-8 with Cu, Mn, Zn, B. Ph is around 6.8-7.
Added Cal+Mg 2 days ago for the first time.
Temp around 27-32 C, RH trying to push down to around 50% with aircon.

 

[Catfish22]

That all seems pretty straight. Indica strains can be cal-mag hogs. If you just started cal-mag I would give it a chance to work. Also let your pH drift within 6.5-7.5 to allow nutrient uptake.

 

[SoOrbudgal]

It's expected to have yellowing leaf at 7wks from older fan leaf. I'd clip off those big fans with yellow it will also help with airflow but just take a few for now.

 

[Tom81]

This is the beginning of Week 8, been feeding cal+mag starting 6 days ago but the yellowing of the leaves is getting worse.
Could it be not enough Mag given? PH measures around 6.8.
Or does it look like something else?

Also the leaves are curling down.
Any suggestions would be appreciated.

 

[Ace1973]

your plant is beginning to mature, nothing to worry about

 

[Tom81]

thanks, yes I thought of that but I mean there are still 2-3 weeks left till harvest and at this rate there will be no green leaves left by then, is that really normal?!

 

[Tom81]

Day 50 - I was gonna start flushing at this point but maybe I should wait a few more days in case the yellowing is caused by N deficiency which seems to be accelerating. Any thoughts?

 

[SoOrbudgal]

Hey Tom81 remove those old yellow leaf not feeding your plant get rid of them. It is cause by N deficiency catus food is only good for so long..............you could go longer had you gotten some bloom food for MJ.

 

[Tom81]

Part of the problem I think is I was feeding only 25% of the recommended dosage of the cactus feed that has only 4% N.

Anyway I fed it once again for the last time - see what happens. And removed some leaves.

 

[Tom81]

Beginning of Week 9 now, gave a last dose of boom feed 6 days ago which seemed to slow down the yellowing a little.
Does it look okay to start flushing it now? I'm a bit hesitant as it probably needs another week or 2 to finish.

Also, the tips and edges of a lot of leaves are brown, could it be light burn? It's a Viparspectra P600 95W (equal to 250W HPS) at 48cm (18.9in) away from the buds.

 

[SoOrbudgal]

Not light burn Tom81 the plant is eating through what's remaining in her once green leaf. All nutrients are used up from soil an soon by her. Now look at the trichomes Tom that's another clue how close she is.

 

[Tom81]

At this point, trichomes are about 25% milky 75% clear so it definitely needs a few more days I think but the leaves, large and small are all dead basically except for a few small ones around the buds.
Not sure if this is normal with autoflowers or it ran out of nutrients too early?

 

[Ace1973]

looks done

 

[TOKABIGONE]

This has much more to do with strain rather than auto or photo. My photos looked a lot like that a week before I took them. Most of the fan leaves gone and sugar leaf too at the end. My Critical Mass strain had almost no amber at all but 80% milky. I never flushed but I'm using coco. I left them to dry in the pot a few days before I cut them.