Backyard Aquaponics
A place to discuss aquaponics

I know potassium deficiency increases susceptibility to powdery mildew and moisture stress. Have you foliar sprayed with Potassium bicarb?

+1 - what Mattyoga said

No.

I added 2.5L of seasol and that seems to have solved the problem of K deficiency. I may have only fixed the acute symptoms leaving the chronic. What is a good source of Potassium Bicarbonate? Brand? Shop?

Check out the difference in prices:

1. $11/100g
2. $5.2/100g
3. $1.3/100g

http://www.melbournefooddepot.com/buy/p ... 00g/F00803
http://greenharvest.com.au/PestControlO ... ducts.html
http://www.anpros.com.au/wine-making-pr ... carbonate/

You could also foliar spray full cream milk as well to help combat the powdery mildew

http://www.organicgardening.com/learn-a ... ery-mildew

I'd recommend option 3

I got mine from here:
http://www.mircobros.com.au/shop/produc ... e_25kg/965 for $130

$0.52/100g

Apparently the eco fungicide may have a detergent in it to help with foliar feeding so def better to use pure pot bicarb if dissolving straight into water. The stuff I have is pure white powder while the eco fungicide is a bit coloured by something.

That is a bit far for me to go.

its a nice state - just don't bring any luggage with you!

25kg is alot of buffering! I split it with someone and still have got heaps - only need to use it in winter as in summer the ph of my top up water keeps the system ph up above 7 so I can't buffer with it - annoying as then I need to get potassium in to the system some other way! (potassium sulphate at present)

A new problem with my toms.

What is going on here?

My money is on Potassium deficiency, or Magnesium

"Typical symptoms of potassium deficiency in plants include brown scorching and curling of leaf tips as well as chlorosis (yellowing) between leaf veins."
http://en.wikipedia.org/wiki/Potassium_ ... 8plants%29

Also a google image search using the words: tomato plant potassium deficiency

..yields intriguing images like:



Magnesium deficiency:



Comparing these images with calcium and iron deficiencies, which look quite different according to the photos on google, you can rule these out

Happy to be proven wrong here though

Oh, and welcome to the Potassium deficiency club

+1 another time for supplementing K if you ask me

I'm barracking for magnesium or manganese on this one
http://customers.hbci.com/~wenonah/min-def/tomatoes.htm

Welcome to the gang

Stuart - are you supplementing Calcium, or adding calcium carbonates to your system by any method?

Reason I ask:

"Calcium is the primary nutrient that complicates potassium in many systems..."

"...when there is lots of calcium present, it can reduce a plants ability to take up enough potassium, leading to deficiencies. The same is also true of magnesium, but to a lesser extent."

http://verticalfoodblog.com/potassium-i ... cs-system/

Yes to all the above.

I think I started with a phosphorus deficiency because of the purple colour of the leave particularly on the viens.

I added some seasol and this fixed things for a while and then I added some more and they took off.

Noticed a calcium deficiency in some of my Zucs and some of the blossoms on the toms looked burnt at the tip. I checked the mussel sheels that I had added to the bed ages ago and they crumbled in my hand. So I added a little lime and I've been throwing in egg shells since.

Got a bad case of midlew and apparently one of the symptoms of potassium deficiency is apparently susceptibility to mildew. So I added some potassium bicarbonate.

Pretty soon after I noticed an iron deficiency which may have occured because I added too much K Iron is still an issue but I'm slowly adding some and watching the new growth to see how it goes.

The latest photos I'm pretty sure are not K deficiency so I'm guessing one of the Ms (Mg or Mn).

This is why I want to employ a greenhouse manager.