Backyard Aquaponics
A place to discuss aquaponics

Hey Folks,

I am currently growing Tomatoes in my AP system, but have been losing my Pink Brandywines to some mysterious disease. The plants go from completely healthy, to a poor state of wilt in just 2 days. The fruit also softens, and wrinkles, almost becoming mushy feeling. This is the second plant that I have lost, with a three week time frame between the two. Does anyone know what these symptoms might be?

Here is a picture of a healthy Pink Brandywine.



And here is the infected plant just 2 days after being perfectly healthy.





Wrinkling Fruit



Roots

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I'd be guessing at collar rot. I think it's a fungal disease and as a total newby in AP I'm not going to suggest a solution as in soil you'd normally minimise the time the plant is wet via deep watering, which obviously goes against AP. Some other AP experts will be able to steer you hopefully.

Hmm, I have no idea. I have researched it extensively after the first one died, but just chalked it up to a bad plant, as the others are all healthy. Then the second one did the same thing. They practically die overnight. I've never seen anything go south so fast.

All the symptoms are of lack of water. I would cut the stem open along the length of it and see if you have a stalk borer inside. The plant doesn't look like it has blight. It could also be a stem rot as was mentioned - the base in the pictures doesn't look that healthy.

Hey Scotty,

I thought it might be a stalk borer as well. I cut the plant to shreds searching, and found no signs of tunneling. The inside of the stalk looked healthy as can be.

There was no sign of blight on the plant at all. It's very strange. Just up and died.

Yes, there is some blackening. What might cause this stem rot? I have voluminous amounts of oxygen being pumped in the system, low DO is not an issue, I'm certain of that.

My water quality is phenomenal, in terms of solids removal, there should not be a toxic build up occurring in the growbeds. All growbeds are flooding and draining properly, roughly every 15-20 minutes.

I think this is a bacterial wilt

Check this out and try the test - http://plantpath.caes.uga.edu/extension/plants/vegetables/TomatoSouthernBacterialWilt.html

More info -

http://giantveggiegardener.com/tag/tomato-diseases/

http://www.clemson.edu/public/regulatory/plant_industry/pest_nursery_programs/plant_prob_clinic/fact_sheet_folder/bac_wilt_tomato.html

Regarding the blackening, normally I would recommend lowering the water level slightly since I think this is algae. I won't do that in this case because of the seedlings in the growbed. If it's not algae and the test above doesn't look like a bacterial wilt then this could be a fungal disease but I really think it's a bacterial rot.

Cheers

Testing now, will upload photos when complete.

The water level in the growbed is at least 2 inches below the surface of where that black spot on the base of the stem appeared. I do not believe it is algae, and none of the other plants exhibit a similar black spot at the base. Bacterial wilt seems spot on, regarding the description, but the test is not showing anything leeching into the water.

Start

5 Minutes Later

Try putting a black piece of paper behind the container, some better lighting might help as well. Based on past experience the turbidity caused by bacteria flowing into the water from the stem would be difficult to see in those conditions. Another thing that I should mention is you need almost 100000 organisms per ml before bacteria cause a visibly turbid solution (I believe this is right, it's been a long time since I learned this).

How long since the plant died and since the cut at the base was made? These might have an impact on the test as well.

I think I'd assume it was bacterial wilt and just clean out the plants that died as well as you can and make certain you don't keep them around where this can spread.

Here's another test for this that's a bit different - http://www.aces.edu/pubs/docs/A/ANR-0862/ANR-0862.pdf


Hope this helps.

I'm also seeing where other sites are saying to use a section of stem just above the roots or at the soil line for the first test.

http://msucares.com/lawn/garden/msgardens/05/050620.html

Thanks Scotty, big help. I'm not ruling out Bacterial Wilt based on the test. All signs do in fact point to bacterial wilt. Nothing else that I am aware of could cause that kind of wilt in such a short amount of time, in an otherwise healthy plant in adequate conditions.

It was nearly 6 hours since I cut the plant, and removed the roots. As you mention, surely this could and would affect the test.

I hope this doesn't spread to the entire system. I'm getting ready to put in 30 tomato plants. I guess we shall see....lol

Pseudomonas solanacearum which is a major cause of this wilt apparently doesn't tolerate a 2% solution of NaCl and there are probably other things that will kill it so if it keeps spreading you may have to shut down and treat the system but at least this bacteria doesn't form spores and you should be able to eliminate it in an AP system. On the down side you'll have to flush it out well and cycle it again and it's always possible the system could be reinfected. I read somewhere that Pseudomonas solanacearum can live for 40 years in water if the conditions are right.

Ryan,really interested in your findings,i have suffered a similar fate i have cut and burnt the lot I’m sure its linked to the Thrips invasion i have suffered,my beds are now infested and i am not sure which way to go next, please check your beds for little white larvae that live on the water line, if no I’m not sure what to do next,if yes we can share information.

Are those the kind that launch themselves when you move near them?