yellowing 4 weeks into flowering.

[mrT]

Strain is Durban Poison in SOG, 600w hps, canna nutrients, an ec of about 0.95, Ph is around 6. handwatering every day.


Im having the exact same problem with this grow as with my other one, 4 weeks into flowering, the upper leaves start to yellow.

I made a tread before, but did not get any fullfiling answers.

Here is the tread :

http://www.icmag.com/ic/showthread.php?t=106278

everything is the same, exept that it is just 1 600w hps, I gave them a litle bit higher EC, but the problem remains.
















Here are pictures of the old grow, 2 weeks before harvest, the upper leaves are really yellow.







please, I really need som help with this. happy new year.

 

[mexilandrace]

I don't really see too much of a problem, other than the fact that you have way more plants than me...

maybe a closer in shot of a specific leaf that bugs you

the older pics look like mag def

 

[mrT]

haha

I dont think its mag def, since mag def shows in the lower parts of the plant, this just in the upper parts.

peace

 

[fuhshietfu]

ur plants look alot like mine currently I always figure it was a mag def? what do you feed for magnesium?

 

[cannaboy]

mrT very nice bunch of plants impressive off 1 600w Tell me what capasity pots are those? Are you still using the cogor nutes or has this one got canna's full spec?


I use coco and have found as fact that it has an ability to retain water longer than any medium.. However usind specific tequnices can improve results. Coco has nothing in it like soil, no minerals except mabe tricholaderma in Coco pro pluss. This means you need to feed it and I have found it releases nitrogen most easily therefore an ability for a plant to have less than it needs if you transpiration rate is fast. Because bloom a+b products for coco bloom are relitively low in Nitrogen as Plants need more p&k in bloom but as nitrogen is more available to the plant in coco and is in lower concentration in standard a+b feed I get a yellowing problem, this wouldn't probably happen in soil as in week 4 as your soil will contain some of its NPK levels still to fight back dark green, several products come with an a+b veg and bloom these have stronger nitrogen levels that helped me combat this. ph I use is strict 5.8 maximum feed is 2.2 if yellowing occurs. I always feed once then ph water once letting them do the work and measure the run off and analyse. Nitrogen is a main ingreedient in clyrophyll and my upper leaves were fighting lower leaver and branches in a loseing battle for food they shed it faster closer to the light further from the pot. You can try to lolipop a bit as well and cut anything that is 30 cm from top of plant before week 2 really try do it in veg is best and you grow fat fingers all the same size..

good luck in the future....