Backyard Aquaponics
A place to discuss aquaponics

I know we have briefly discussed tomato diseases in the past, but in my searches I have found little information about causes, preventions of diseases and what varieties/hybrids work best in AP under what conditions.

In El Salvador I have designed a system that one can build using all local components with the exception of the pump for about 280 USD. It is about 600 gallons of fish tank and enough grow beds to hold 200 indeterminate tomatoes. On paper, each of these tomato plants should produce a minimum of 9 kilos (20lbs) of tomatoes which are easily either consumed or sold locally in the markets. In theory, I should be able to generate with this system about $3000 per year in tomatoes at local prices. The ROI in theory looks pretty good, but the reality has been something else. Part of my failure is not really having a strong background on the plant side of things. Mechanically everything works well and the fish are growing well.

My problem is that tomatoes germinate and grow to about 300mm (12inches) and then the diseases hit. I have had people tell me that some of the things are viral, other cases are fungal, and some are environmental, (too much sun/heat/shade etc). Those who have followed my threads in the past know that I am making an effort of providing income and supplemental food sources at a low cost in El Salvador and all of it has to be sustainable locally. Unfortunately all my figures and theories are predicated on the production of tomatoes and cucumbers. I need the help of this forum in that I would like information about successes and failures you all are having in tomato production and what your are doing to prevent diseases and still protect the fish.

As usual, POST PICTURES>

Here is a quick overview of the system.

500 Gallons of Fish water
60 fish averaging 450 grams - Tilapia
Media - Lavarock
Growbeds - 2 Ferrocement, 2 Wood with plastic liner
650 gph fountain pump
Flood and Drain System

Location: On the second floor terrace of a rented house; thus, nothing permanent.

I wish I could help, but don't know enough about your climate.

A few more details

At present Daytime temps about 36-38 degrees, Night time 27 c

At present we have no rain as it is the dry season.

do the toms do it different in the timber GB?

do the toms do it different in the timber GB?

no, not really, I have problems in all my grow beds. Some of it could be from proximity, viruses spread as do fungi. But weirdly enough, one plant will croak and the next one over is healthy and stays healthy.

that odd
Makes me think it might have something to do with water delivery

How so? What do you mean by water delivery?

Make sure you have no spray / splashing onto the plants ,, that will quickly make fungals a major problem ,,

I was thinking anaerobic

Tomatoes can be very tricky plants in some situations and monsters in others.

Toms are very greedy! In Hydroponics, they will gladly accept nutrients so strong that the trunechon might not be able to measure them. To really get specific about growing toms, you will probably need to invest in a few things (now I'm not really an expert here because I've only grown bumper crops of the cherry and grape tomatoes so please find more evidence before you simply trust what I say here.) You will probably need a good source of potassium supplement (maxicrop or seasol) which will probably also take care of trace elements. Healthier plants are more likely to fight off disease. Look into mail ordering high quality tomato seed that is well suited to greenhouse growing (I'm assuming that your climate is pretty humid even in the dry season, greenhouse growing is usually more humid that field cropping.) And finally, you will probably want to order a test tube and dropper type test kit so you can get a more accurate idea of your water tests (last I knew you were using strips.) Knowing your pH may help you to optimize your plan of attack. I'm curious about how much the cement grow beds might be affecting the pH of the system though tomatoes seem to be more tolerant than cucumbers about the pH and iron content of the system.

There are lots of hydroponic, garden, and tomato sites that have tons of info about growing tomatoes. Some reading through some of those sites might help you pick up some things there.

Now when you mention that each plant on paper produces and specific weight in produce.......... I have a little trouble with claims that a plant or a system will produce specific amounts. Just because on award winning plant somewhere produced some amount of produce, that does not mean that all of that species of plant will always produce that much!

I don't know much specifically about tomato diseases other than Blossom End Rot which is actually a calcium deficiency in the fruit and not a communicable disease. There are many things going on in my garden that would probably be viewed as major disease epidemics that I have been kinda leaving to go their course since I figure whatever beneficial process might help me with them needs a spike of that disease before it can take hold. I'm thinking mainly of powdery mildew and downy mildew, then again, they don't seem to be killing off the plants before I get a good harvest so.....I'll leave it alone. I have tomatoes with leaves curling but they still produce. some plants look whimpy so I pull them. Others are beasts so I root the cuttings as I prune the suckers.

Tomatoes will use lots of water but they can be prone to root rot so keep them away from waterlogged parts of the bed. The lower leaves of tomato plants often whither and die and that is kinda normal, at least for indeterminate types.

I've heard of using sprays like baking soda or hydrogen peroxide (diluted of course) on the plant to battle some diseases. Other people will tell you to pull up and burn offending tomato plants and the tell you to sterilize the world to avoid the tomato diseases while other people happily compost diseased tomato plants and rarely have disease problems in their gardens. So have I said enough to totally confuse everyone yet?

Thanks for your input. I more thinking along the lines of what are people doing in their systems to prevent disease, and is anyone else growing toms on a a large scale.

Believe me I have gone to other sites and explored. While I get ideas about the diseases, very few of their solutions are applicable to AP since the over riding solution is copper sprays. Not really an option in an AP system.

Seaweed extract sprays might help

aerated compost tea sprays

aerated worm tea sprays

even aerated corn meal tea spray (this was a kinda home brew idea I saw mentioned for tomatoes somewhere)

These may all help in the context of improving plant health and bio-diversity helping to combat disease organisms by out competing them.

With all sprays, make sure to dilute enough and spray when appropriate (this gets tricky in hot humid climates since you don't want to spray before or during the heat of the day since that can cause burning but you might also not want to spray at dusk since that leaves the plants wet overnight which can sometimes cause problems as well, might mean spraying at dawn but test to see how the plants do with it.)

I've also heard of some home brew type methods that might use baking soda, hydrogen peroxide, vinegar, milk, corn meal, garlic, or hot peppers. If used quite carefully, these might have some used as sprays around aquaponics. Be sure not to overdose with any of them of course. (Be ware of oils or soaps around AP since they can suffocate your fish.)
I've even heard of using milk as a spray to combat some things, didn't work on my powdery mildew though, perhaps I'll try it on the downey mildew I though I saw. Now milk may not be the best ingredient to actually battle a disease but I did find that it seems to be a good choice as a spreader/sticker since you need to avoid soap and dish soap in sprays used around Aquaponics. Most home brew plant sprays use some dish soap so perhaps substitute some dried milk instead to make it fish safe.

It might also be worth finding out if there are any specific deficiencies in the soils around the volcano where you got your media. Volcanic rock might be pretty good but if the farmers around there have to add something special to grow stuff well, you might need to look into ways to supplement that trace element. Many diseases can be linked to deficiencies.