Help Identifying deficiency...boron, magnesium?

Hi Guys,
Day 42 in Coco. Feeding Ionic Coco Bloom with added 2.0 ec of PK 13/14, 1.6 ec total.

Last week started noticing yellowing of some top leaves and brown rust type spots on mainly one big bud and now starting to notice it on 2 other buds.

Edges of the leaves of the affected bud are rolling inwards and kind of becoming slightly crispy, crumbly.

I only started adding the PK when I noticed this to see if it helped

Can some one help identify what is causing this?

Not a deficient look, maybe salt build up? Leach them a little with a balanced low ppm nute mix. That's what I'd try.

Top down yellowing, or yellowing of new growth is usually a PH problem, or it could be that your plant is root bound. How big are your containers, and what is you PH.

Also Cal/Mag def looks like chicken pocks.

Bugeye said:

Not a deficient look, maybe salt build up? Leach them a little with a balanced low ppm nute mix. That's what I'd try.

Click to expand...

I think you maybe right about salt build up.
I flushed with plain water a week ago when I first noticed some yellowing. Then I carried on with the nutes next day.
Would you suggest I flush again and use low nutes? ...for how long? Will I expect to see recovery of the affected buds... will the yellowing come back to a healthy green or just no spreading of problem?
I am in 11 litre airpots and keep PH between 5.5 - 6.2.
Thanks guys.

it might not be a good idea to continue nutrients after flushing. only time will tell if your plants survive.

[QUOTE=" Will I expect to see recovery of the affected buds... will the yellowing come back to a healthy green or just no spreading of problem?
I am in 11 litre airpots and keep PH between 5.5 - 6.2.
Thanks guys.[/QUOTE]
Hey throbster, Check out the picture at the bottom which is a typical Calcium deficiency. Take a look close at your leaves that are not totally screwed. See if you can see that going on. That would also make the plant not handle higher temps too. I'm not saying that is your problem, but you want to rule it out since it is common in coco grows. The pics I'm not sure but your description of yellowing top end and brown spots fits.
Also just to be sure give us some details on what lights you are using and what distance from the top buds it is as well as what temps your grow room is.
How often are you watering?
Its likely that the damaged leaves wont go back to been green



.

coreywebster said:

[QUOTE=" Will I expect to see recovery of the affected buds... will the yellowing come back to a healthy green or just no spreading of problem?
I am in 11 litre airpots and keep PH between 5.5 - 6.2.
Thanks guys.

Click to expand...

Hey throbster, Check out the picture at the bottom which is a typical Calcium deficiency. Take a look close at your leaves that are not totally screwed. See if you can see that going on. That would also make the plant not handle higher temps too. I'm not saying that is your problem, but you want to rule it out since it is common in coco grows. The pics I'm not sure but your description of yellowing top end and brown spots fits.
Also just to be sure give us some details on what lights you are using and what distance from the top buds it is as well as what temps your grow room is.
How often are you watering?
Its likely that the damaged leaves wont go back to been green


The rest of the leaves don't look like in the picture for Calcium deficiency.
Lights are LED cobs at 19-20 inches from the canopy. Canopy temperature is 29-30C degrees. Watering everyday.

[QUOTE="
The rest of the leaves don't look like in the picture for Calcium deficiency.
Lights are LED cobs at 19-20 inches from the canopy. Canopy temperature is 29-30C degrees. Watering everyday.[/QUOTE]

Cool, that's one thing ruled out. Your temps are a bit on the high side, Cobs kick out some serious light too. You might want to raise your light a few more inch and try and cool your room down some. Do you have a good fan blowing across the canopy.
The leaves at the top are canoed which is usual with heat stress. It looks like the plant or that top in the pic is considerably worse than the tops in the background, is it also looks slightly taller and therefore a bit closer to the light??
Get those temps down somehow. How many lumens per square foot are you running at?

Good luck

I have flushed fully with ph'd water. The main affected bud does look worse. The bud smells strong and musty, kind of like bud rot but no actual signs of mold.