Backyard Aquaponics
A place to discuss aquaponics

I have an issue with my tomato plants. Old leaves get spots, those spots grow, and the leaves die off. I don't see any bugs. I've used Iron Chelate, Sea Sol, and trace minerals. Maybe not enough as I have 3500 gallons to dilute with. I have a pH of 7.4 and Nitrates of 40, ammonia and Nitrites are zero.

It only seems to be affecting tomato plants and only the ones in the Aquaponics system, I have a raised bed in the same greenhouse and they are not affected. New leaves seem fine. Almost like the plants are eating themselves to get the nutrients they need. Is that even possible?

Thank you,
Jason

http://vegetablemdonline.ppath.cornell. ... ly_Tom.htm

early blight??

Yep, looks like Early Blight to me as well.

I'd trim the affected foliage and throw it in the trash. This is caused by a fungus so you want to reduce the amount of infectious material in the area. This will help with air movement through the plants as well. The plants will still produce a tomato crop. Once the affected foliage has been removed take a look at your growing conditions. Lack of air circulation and too much moisture are likely part of the problem. If you go out at night is there condensation on the plants, the greenhouse ceiling or along the wall behind them that may be either dripping on them or coming in contact with the plants? If you increase the air movement it will be harder for the condensation to occur. If you've been using a foliar spray I would stop and find another way to add nutrients or whatever. I'm sure others will have suggestions this is a very common disease that shows up after rainy weather (which you don't have in your greenhouse but probably do have high humidity).

Thank you. I think it really started thriving during the colder months when I had it locked up pretty tight at night. The ceiling used to drip. Now I have it it open, humidity isn't as much as an issue. I'll get it all out of there.