Purple curlies are back, what is this ??

[zapatoloco]

This has been showing up on some individuals of various strains , especially the later blooming varieties.

The purpling and occasional leaf deformation starts in August and can, in the worse cases, become so bad as to totally inhibit flower formation. The worst cases show a complete dark purpling of the ends of branches.

Interestingly plants continue to grow and can get quite large when suffering from this condition. In the least affected plants the purpling is sometimes outgrown and flowering resumes pretty close to normal.

 

[zapatoloco]

 

[zapatoloco]

A few more ...

 

[RetroGrow]

Almost looks like a fungus...

 

[tokinafaty420]

Its not fungus. It's a phosphorus deficiency caused by colder temperatures. Been having colder nights lately zap?

 

[zapatoloco]

No colder temps recently. I've been seeing this in a particular set of spots for a few years now and plants have been receiving a normal feeding regimen including phosphorous. This regimen has plants performing normally in most cases.

 

[tokinafaty420]

No colder temps recently. I've been seeing this in a particular set of spots for a few years now and plants have been receiving a normal feeding regimen including phosphorous. This regimen has plants performing normally in most cases.

The lack of phosphorus in the soil or your nute mixture isn't the reason for the deficiency. It is caused literally by colder temperatures locking it out. Preventing it from being mobile.

 

[zapatoloco]

Thanks Tokin,...but like i said : side by side some get it some don't. And there hasn't been a cold snap in the period when this appeared and last year the purpling stopped in some plants and they resumed normal flowering later in the season when it was colder. In 23 years of outdoor growing i have only seen this peculiar type of purpling in the last two.

I have frequently seen a lesser form of purpling which is clearly due to phosphorous deficiency. This usually happens around the switch to flowering and everything falls into place once the feeding regimen is adjusted.

This purpling is different, phos. def. is the first thing that obviously comes to mind but even direct foliar applications of P don't seem to be of any help. Many of the affected plants are also in containers which can get pretty warm in the sun so i doubt temps in the root zone would get cold enough to cause problems, especially considering that early august is not at all a cold time of the year around here.

I have been suspecting something in the soil, maybe even something as arcane as Walnut toxicity (these guys grow in the vicinity of the affected spots).