Malawi Gone Wrong?.

Sunbiz1

Sunbiz1

Well-Known Member
Hi all,

Can anyone identify the cause of these rust colored patches?. I have never seen this before, and it's only affecting the Malawi. There are 2 other strains in the same medium/lighting etc. right next to this plant that are just fine. They all need re-potting soon, only this looks like some sort of fungal disease as opposed to nutes/ph issue.

TY in advance for any input.:peace:

View attachment 2904762View attachment 2904763
 
Sunbiz1

Sunbiz1

Well-Known Member
Hmm, 76 views and not one guess?.

Been googling pics of leaves, and nothing matches my own photo.
 
L

LarryOG

Well-Known Member
Calcium deficiency, get some dolomite lime at Home Depot and sprinkle a thin layer to just cover soil and water it in. You'll see no more rust spots appearing but the old ones won't fix themselves either. Don't add anymore fertilizer except for the dolomite lime.
 
Sunbiz1

Sunbiz1

Well-Known Member
LarryOG said:
Calcium deficiency, get some dolomite lime at Home Depot and sprinkle a thin layer to just cover soil and water it in. You'll see no more rust spots appearing but the old ones won't fix themselves either. Don't add anymore fertilizer except for the dolomite lime.
Click to expand...
This would make sense, and I already use D.lime...probably just not enough. I am re-potting today, so will use more and back off on the only other nute being used:
http://www.espoma.com/p_consumer/tones_plant.html
Which is that.

TY!
 
jondamon

jondamon

Well-Known Member
It does look similar to a Ca def but generally with Ca def the spots are more red and definitive.

These look more like irregular rust brown patches which I generally assimilate to magnesium deficiency.


image.jpg
 
Sunbiz1

Sunbiz1

Well-Known Member
jondamon said:
It does look similar to a Ca def but generally with Ca def the spots are more red and definitive.

These look more like irregular rust brown patches which I generally assimilate to magnesium deficiency.


View attachment 2905883
Click to expand...
Hmm, only reservation I have with this is no discoloration on my plants of leaf veins...just the spotting.
 
jondamon

jondamon

Well-Known Member
Sunbiz1 said:
Hmm, only reservation I have with this is no discoloration on my plants of leaf veins...just the spotting.
Click to expand...
That's why I pointed you at diagram C.

It is one of a few different symptoms.

Unfortunately I've found that you don't always get the yellowing first and then the patches or burnt curled up tips etc.

It can be either or.

Its only as the deficiency progresses that you may get other symptoms.

For about 12months I assumed the rust brown patches I was getting on my grows was due to calcium. So I would up the Ca (as I use mono Ca and mono Mg) which only exacerbated the problem.

At that point I looked hard again at my base nute (6-3-8) which unfortunately wasn't formulated right for use in coco and the excess K wasn't helping matters because of cocos tendency to produce small amounts of K. The produced K along with the elevated K and the extra Ca caused all sorts of weird necrosis by harvest.

In my base at that time there was 2% Ca and 1% Mg.

Now my base is 5-4-3 with 5% Ca and 2% Mg.

The Mg IMO still isn't enough in my base and I have to add extra during flowering to compensate otherwise I start with blotches such as those you're showing.



J
 
jondamon

jondamon

Well-Known Member
Also something to bare in mind is that its pretty hard to overdose on Mg as long as you keep your EC at a reasonable level. IME under 1.2EC when applying Mg as a root drench for a deficiency.



J
 
Sunbiz1

Sunbiz1

Well-Known Member
jondamon said:
That's why I pointed you at diagram C.

It is one of a few different symptoms.

Unfortunately I've found that you don't always get the yellowing first and then the patches or burnt curled up tips etc.

It can be either or.

Its only as the deficiency progresses that you may get other symptoms.

For about 12months I assumed the rust brown patches I was getting on my grows was due to calcium. So I would up the Ca (as I use mono Ca and mono Mg) which only exacerbated the problem.

At that point I looked hard again at my base nute (6-3-8) which unfortunately wasn't formulated right for use in coco and the excess K wasn't helping matters because of cocos tendency to produce small amounts of K. The produced K along with the elevated K and the extra Ca caused all sorts of weird necrosis by harvest.

In my base at that time there was 2% Ca and 1% Mg.

Now my base is 5-4-3 with 5% Ca and 2% Mg.

The Mg IMO still isn't enough in my base and I have to add extra during flowering to compensate otherwise I start with blotches such as those you're showing.



J
Click to expand...
What's odd is, I have used the same blend on at least 6 other strains...without any problems. Then this Malawi comes along, and now I'm making 2 different soil blends.
 
jondamon

jondamon

Well-Known Member
Sunbiz1 said:
What's odd is, I have used the same blend on at least 6 other strains...without any problems. Then this Malawi comes along, and now I'm making 2 different soil blends.
Click to expand...
I had 2 different pheno's of the same strain react differently to the old base nute.

Its just the way it is. Some are Ca hungry others Mg. some crave more N while others not so much.



Shit happens. We just have to read our plants and respond accordingly.




J
 
H

hopesluck

Member
whats your humidity? some strains take higher humidity for the stomata (openings on the bottom of the plant that allows the intake of co2 and other gases ) to stay open otherwise the metabolic system shuts down and can cause false deficiencies of the main 6 high demanding nutrients, nitrogen, potassium, phosphorus, mag, cal, and sulfur. malawi is a strain that comes from southeastern africa which is a very humid area. so thats just something to keep in mind.
 
Sunbiz1

Sunbiz1

Well-Known Member
hopesluck said:
whats your humidity? some strains take higher humidity for the stomata (openings on the bottom of the plant that allows the intake of co2 and other gases ) to stay open otherwise the metabolic system shuts down and can cause false deficiencies of the main 6 high demanding nutrients, nitrogen, potassium, phosphorus, mag, cal, and sulfur. malawi is a strain that comes from southeastern africa which is a very humid area. so thats just something to keep in mind.
Click to expand...
Shall check humidity in morning w/hygrometer...I'll bet it's too low.

If it is, that's a problem b/c no other strains currently require higher humidity in same room.

:peace:
 
H

hopesluck

Member
i had the same problem with mine, i am growing blue dream and they were the only ones that got the same as you are describing and i bought a humidifier and it went from being 19-25% average to 54% and they took off over night. i also would like to direct you to a item i picked up and it helps out so much. http://www.amazon.com/Zoo-Med-HygroTherm-Temperature-Controller/dp/B0019IHK9Q/ref=sr_1_1?ie=UTF8&qid=1385372353&sr=8-1&keywords=hygrotherm
its a hygrotherm which controls heat and humidity at the same time, its easy to program and i just hooked up the heat to my exhaust fan to kick on when it hits 82 and to kick on my heater ( if needed ) at 70 ( also starts to slow metabolism below 70 and above 90 it slows as well ) for $50 you cant beat automation of climate. its the best item i could find after 6 hours of looking and i found another but it was $150 and it did the same thing but wasnt accurate. it has a photocell so if you every lose power while away it'll save your presets and start back up when electricity is up.
 
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