Aquaponic Gardening

A Community and Forum For Aquaponic Gardeners

So mainly on my older leaves on my cukes, crooked neck squash and zuchinni the leaves are going just on the tips of the stem soft/limp and yellow to brown in the middle/spotchy and then shriveling up and dying. The system is about nearly 2 months old. I have 18 tilapia and water test below

ammonia o ppm

nitrite       o  ppm


ph     7.0 to 7.2  (just started bringing it down from 8.0ppm. Slowly over the last 2 days with muriatic acid. (leaves were turning beforehand.

Nitrates...color on test is deep red. So high level. I just added some maxi crop yesterday hoping today there would be no more leaves dying. I had cut all the others off and then same thing when I got off work tonight. Took some more off that had went limp and brown / yellow. Almost greyish from being dead. Actually it seems it not that I think about it some old and some new leaves. The ones I cut yesterday have already started coming back. No leaves yet but the stems grew like an inch today.

What am I missing. I put a few ounces of fish fertilizer in as well as it is nitrogen, phospate? and other nutes.

Help!

Views: 2392

Reply to This

Replies to This Discussion

Sorry, added maxicrop W/ iron...

Hi Jamie. Some pics would be nice. I suspect there are a few different things going on there.

Boy, did you pick a difficult family of cultivars to grow in a brand new AP system. Cucurbits are really heavy feeders (more so than even tomatoes) and have particularly hogish need of magnesium and potassium (which your not going to get a lot of from MaxiCrop+Fe, nor from fish effluent right off the bat in a new system).

What seems to ride shotgun with weak, deficient cucurbits, are disease like powdery/downy mildew (Pseudoperonospora cubensis), anthracose (Colletotrichum orbiculare), leaf blight (Alternarai cucumerina)...all of which fit your generic description, but so do certain nutrient deficiencies.

The yellowing along the very edges of the leaves, would be your potassium deficiency taking its toll. Usually, if you let it go this will be followed by the edges turning white-ish brown and necrotic lesions throughout the broad surface of the rest of the leaf.

The yellowing between the veins of some of the older leaves would be the work of not enough magnesium. Followed by more general necrosis and whitening....Leaf turning brittle and dying. All of this makes for wonderful disease vectors...But some pictures (of the various leaves) would be worth a thousand words...

New leaves look alright because many plant essential elements are mobile within the plant, some like iron are not mobile. This is why iron deficiencies will show first in new leaves, while say, a magnesium deficiency will show first in older leaves. Since the plants pulls the Mg from the old to support the new growth.

 

I think there is mildew on the leaves. It looked powdery this morning. My leaves are all wet in the mornings. Would that have anything to do with it. I'll get some pics tomorrow. Just cut more leaves. If I don't catch it soon, they will be gone thru w/ no leaves left. Now some of the tomatoes have died. Ugggh...everything was doing so well. There is plenty of nitrates but would the fish fertilizer not get it the mag and pot as it has potash in it as well?

Powdery mildew (Blumeria graminis) look like whitish patches on the leaves, and is one of the very few fungal diseases that do not require that the leaf be wet in order for it to take hold...You mentioned yellowing (downy mildew looks like little yellow patches, but again, so does a ton of other stuff that may fit that word description...without pics, who knows...

Fungal diseases notwithstanding...No, you are probably NOT going to get enough Mg or even K out of fish feed/poo in a heavily stocked (plants) and new system in the first couple of months to support the plants you mentioned. There is a very good reason people either stick to leafy greens the first year or so, or come up with a good buffering/additive regime and/or cater to the needs of such heavy feeding plants, or plant way less...or all three.

Cucumbers, zucchini and squash (all the things you mentioned) are the Chevelle 442's of the gardening kingdom (with tomatoes being slightly less guzzling). It seems unrealistic (depending on how you cycled, and how you operate your system) for a brand new AP system to support many, or even any (again, depending on how/what you operate) of those kinds of plants until your system matures. Nitrates alone are hardly enough. (Imagine you trying to live from birth to toddler to puberty on milk alone)...It either takes time, or added intervention on your part to pull off something like that. 

Don't get discouraged, just take it back down to Earth because you probably dont have the fuel to power those beasts.

How many of those plants total do you have anyway? Everything does well when they are just seedlings/young plants...



Vlad Jovanovic said:

Powdery mildew (Blumeria graminis) look like whitish patches on the leaves, and is one of the very few fungal diseases that do not require that the leaf be wet in order for it to take hold...You mentioned yellowing (downy mildew looks like little yellow patches, but again, so does a ton of other stuff that may fit that word description...without pics, who knows...

Fungal diseases notwithstanding...No, you are probably NOT going to get enough Mg or even K out of fish feed/poo in a heavily stocked (plants) and new system in the first couple of months to support the plants you mentioned. There is a very good reason people either stick to leafy greens the first year or so, or come up with a good buffering/additive regime and/or cater to the needs of such heavy feeding plants, or plant way less...or all three.

Cucumbers, zucchini and squash (all the things you mentioned) are the Chevelle 442's of the gardening kingdom (with tomatoes being slightly less guzzling). It seems unrealistic (depending on how you cycled, and how you operate your system) for a brand new AP system to support many, or even any (again, depending on how/what you operate) of those kinds of plants until your system matures. Nitrates alone are hardly enough. (Imagine you trying to live from birth to toddler to puberty on milk alone)...It either takes time, or added intervention on your part to pull off something like that. 

Don't get discouraged, just take it back down to Earth because you probably dont have the fuel to power those beasts.

How many of those plants total do you have anyway? Everything does well when they are just seedlings/young plants...

I didn't mean nutes from the fish themselves but from alaskan fish fertilizer. Nitrogen, magnesium, etc. Ya, I'm sure I have to many. I already thinned them out just a bit ago. Will do some more tonight after work. My nitrates, though, are off the charts. Still, though once they really start needing them is when I'm sure it'll crash down to not enough. If my fish were bigger yet but they are still small. Live and learn. I'll thin the heard and hopefully. I literally cut most all the leaves of the remaining plants. Sprayed them with milk, water and baking soda. Will that help.



James (Jamie) Barbaria said:



Vlad Jovanovic said:

Powdery mildew (Blumeria graminis) look like whitish patches on the leaves, and is one of the very few fungal diseases that do not require that the leaf be wet in order for it to take hold...You mentioned yellowing (downy mildew looks like little yellow patches, but again, so does a ton of other stuff that may fit that word description...without pics, who knows...

Fungal diseases notwithstanding...No, you are probably NOT going to get enough Mg or even K out of fish feed/poo in a heavily stocked (plants) and new system in the first couple of months to support the plants you mentioned. There is a very good reason people either stick to leafy greens the first year or so, or come up with a good buffering/additive regime and/or cater to the needs of such heavy feeding plants, or plant way less...or all three.

Cucumbers, zucchini and squash (all the things you mentioned) are the Chevelle 442's of the gardening kingdom (with tomatoes being slightly less guzzling). It seems unrealistic (depending on how you cycled, and how you operate your system) for a brand new AP system to support many, or even any (again, depending on how/what you operate) of those kinds of plants until your system matures. Nitrates alone are hardly enough. (Imagine you trying to live from birth to toddler to puberty on milk alone)...It either takes time, or added intervention on your part to pull off something like that. 

Don't get discouraged, just take it back down to Earth because you probably dont have the fuel to power those beasts.

How many of those plants total do you have anyway? Everything does well when they are just seedlings/young plants...

So what additives to I need to add to supplement. I have the maxicrop w/ iron. I also have alaskan fish fertilizer. What else do I need to add to assist in supplementing once I thin them out more?

Nearly as soon as the leaves get spotchy they go limp and just curl up to nothing. They don't stay stiff with leasions or anything like that. They go completely limp. Shrivel up and die. But before hand it looks like this morning a greyish powder on edges or up the middle. Either way. Just depended on the leaf. But indeed it does not take them but a few hours to just go completely limp and curl up to nothing.

I take it you don't own a digital camera hehe :)

Ok, so there's a greyish powder (is it kinda fuzzy when you look closely or with a magnifying glass)?

And they go limp real fast...like a wilted mushy limp? If that is the case that sounds like botrytis (grey mold). Botrytis seems to be an opportunistic fungus that will attack weak, malnourished or injured plants. Especially if they are packed in real close. I've only really dealt with it once on one plant. (Powdery mildew is a much bigger and more common problem for me here)...

At any rate, I'm sorry to hear your plants are not doing so well. I don't think you'd like or want to hear anything else I'd have to say :)

Maybe you pull out the hopeless and try battling it with potassium bi-carb, or dilute potassium hydroxide to a pH of 8 to 8.4 and spray the leaves (that's how I successfully dealt with my bout the on time)

But, I sorta feel like without addressing your nutrient situation it might be kind of a lost cause. IDK. Good luck.

Ya, my sister has it. Have to get it back. Course I cut all the leaves off. I suspect there will be more, though. I have added maxi crop w/ iron, fish fertilizer. I am getting some potassium bicarbonate today. Hopefully they will have just straight chelated iron. I did pull out about half of the plants also. Was overcrowded. Do I get the potassium hydroxide at the hardware or garden store also and what is it for?

If your getting the potassium bi-carb just stick with that. No reason then to mess with the potassium hydroxide then. To make a long story short, basically they'll do the same thing, only the hydroxide version is very strong and very caustic. So it needs to be diluted to a 'safe' pH. The bicarb is already at about the 'right' pH (8 or so) and is so is not dangerously caustic. 

If you have some Epsom salt to add for Mg it is an ok and fish safe source (Epsom salt... MgSO4-7H2O is about 10% Mg content). You can use the search field in the upper right hand corner to find one of the 'walk-through threads' on how much Epsom to add etc...if you wish.

If you should need to buffer up your systems pH, just use the potassium bi-carb, that should help with the K deficiencies. Those two will help add some of that needed Mg and K your cucurbits need. It could only help in their recuperation. Cukes, squash, zucchini really are hogs when it comes to Mg and K. They generally need as much K as they do N. And as much Mg as they need Ca. Which in the crop/plant world is really quite high...They are very heavy hitters. Luckilly this can easily be accommodated.

When you say "fish fertilizer" what exactly does that mean?

Good day.

 Vlad since Potassium Bi-carb is also used as a fungicide have you observed any suppression of funguses in cucurbits thru the systemic application when Potassium Bi-carb is used as ph buffer?

thank you,

kenny

If you mean systematic application as a buffer, no. I don't think system water would benefit much from a fungicidal aspect. It seems to me that much of the fungicidal effect of KHCO3 comes from the fact that it will raise the pH on the surface of the leaf beyond what the fungi can deal with. As a buffer you'd never get into that pH territory.

  

Reply to Discussion

RSS

© 2020   Created by Sylvia Bernstein.   Powered by

Badges  |  Report an Issue  |  Terms of Service