HELP - Tomato plants yellowing with brown spots

[Nick Scud]

HELP - Tomatoes:  Plants were in overdrive!  starting fruiting amazingly, but now leaves have yellowed/browned and started dying in spots - fruit is hanging on and gaining some color now. pH has gone from alkaline (8.0+)  to slightly acidic, around 6.6-7.0 range.  If this is a nutrient dificiency, please advise on what to add, that won't hurt fish.  I believe it can be calcium/iron deficiency, but not sure.  I don't want to lose these awesome plants!

thanks!

-n

[Tim Day]

Hi Nick,

Is it new leaves or older leaves that are yellowing? The pH drop should be beneficial to your plants so I wouldn't worry about that.

If it is iron, and you want to save specific plants, in addition to adding a teaspoon of chelate to the system you can also mix some up with water and spray the affected plants directly where the yellowing is (new leaves for iron).

Photos would be useful, it could also be bugs or disease. Is it a media based system?

[Nick Scud]

Media based - mix of Stalite and Crush-Run granite gravel.  I thought lowering pH would be good.. but plants show otherwise.  I'll try to post some pics.  - It started as OLD leaves yellowing/brown spots, however it seems to be rising UP the plant, and starting to hit newer leaves sooner, if that makes sense..  I need help!!

-n

Tim Day said:

Hi Nick,

Is it new leaves or older leaves that are yellowing? The pH drop should be beneficial to your plants so I wouldn't worry about that.

If it is iron, and you want to save specific plants, in addition to adding a teaspoon of chelate to the system you can also mix some up with water and spray the affected plants directly where the yellowing is (new leaves for iron).

Photos would be useful, it could also be bugs or disease. Is it a media based system?

[Tim Day]

That sounds like it could be nutrient, but don't rule out other possibilities either. Old leaves yellowing first indicates that it would be a MOBILE nutrient deficiency (because the nutrient will move to the new leaves, leaving the old ones without replenishment to turn yellow). Check out the flow chart on page 6 of this:

http://landresources.montana.edu/NM/Modules/Module9.pdf

The chart in this article shows the effect of pH on the ability of plants to uptake various nutrients. Probably not an issue, unless your pH gets lower and the nutrient is magnesium.

http://scienceinhydroponics.com/2010/06/understanding-ph-in-hydropo...

Have a read of that first link. Also look for little tiny spider webs on the leaves, it could be teeny spider mites too.

Good luck!

[Nick Scud]

I believe it could be pests..  i DO see little webs, that are like mites.  Any recomendations on treatment options??  I've heard something called "3 in 1" is a good natural pest control that won't screw up fish tank environment

-n

Tim Day said:

That sounds like it could be nutrient, but don't rule out other possibilities either. Old leaves yellowing first indicates that it would be a MOBILE nutrient deficiency (because the nutrient will move to the new leaves, leaving the old ones without replenishment to turn yellow). Check out the flow chart on page 6 of this:

http://landresources.montana.edu/NM/Modules/Module9.pdf

The chart in this article shows the effect of pH on the ability of plants to uptake various nutrients. Probably not an issue, unless your pH gets lower and the nutrient is magnesium.

http://scienceinhydroponics.com/2010/06/understanding-ph-in-hydropo...

Have a read of that first link. Also look for little tiny spider webs on the leaves, it could be teeny spider mites too.

Good luck!

[Tim Day]

Yeah spider mites then... little pains in the butt

There is an organic spray called "liquid ladybug" that is formulated specifically for spider mites. You can get it from The Aquaponic Source: http://www.theaquaponicstore.com/Liquid-Ladybug-32-oz-p/aichf015.htm

Alternatively, you could try introducing actual ladybugs to eat them, but if your system is outdoors they will probably just fly away.

If it is nutrient (and it probably isn't an issue at all if there are mites there), it would most likely be potassium in my opinion. The next few times that you raise your pH, use a potassium carbonate solution and that should introduce plenty of potassium to your system.

[Nick Scud]

RAVAGED... my poor tomato plants..  they look like they're gone through hell.  Most foliage is dead/dark brown.  there are soe new shoots.  The fruit is mostly hanging on, although some of it got munched - I hope we'll be able to save alot of it!!  This is amazing..  I guess God taketh as fast as he giveth..  I need to be more pro-active about responding to pests!!  Some people have said plants will look extra "worse" because of their lifecycle and the fact that the fruit is finishing now.  Can these still be salvaged?  ROots and stalks still look vital, as well as the fruit..  thanks all, and thanks Tim, for all your input!

-n

[Alex Veidel]

Spider mites don't explain the brown spots, unless you're talking like microscopically small brown flecks, which would be tiny piles of spider mite feces. If you want to be sure of spider mites, find someone with a basic microscope and take a look at your leaves.

However, I think you're describing bacterial spots. Leaves look like this?

[Nick Scud]

Not exactly...  but maybe close, or a few days ago.  now there's hardly enough vegetation to see the spots, the roughage has died off.  fruit still hanging and developing color, so I guess that it good.  there are barely some new shoots at top, but those are quickly getting ratty looking too- real fast.  Was not like this until recently..  if it is bacterial, what to do then Alex??

thanks

-nick

Alex Veidel said:

Spider mites don't explain the brown spots, unless you're talking like microscopically small brown flecks, which would be tiny piles of spider mite feces. If you want to be sure of spider mites, find someone with a basic microscope and take a look at your leaves.

However, I think you're describing bacterial spots. Leaves look like this?

[Kent Evans]

Nick,

Your description sounds like a fungus, maybe a blight. Did you start your plants from seed or buy them from a store? Is there brown spots on the stems? Heat in the summer here in Florida can help cause a fungus that kills the plants this time of year. No way to stop it now. I have lost 8 plants in my soil garden outside in the last 2 weeks. Happens every year. Fried green tomatoes anyone?

[Alex Veidel]

Oooh, yes please :)

Kent Evans said:

Fried green tomatoes anyone?

[Alex Veidel]

Well, a little google-bird told me a few pointers, but I have no personal experience with getting rid of bacteria spots. I think I've got them too, but they've been constrained to just a couple leaves for a while, so I don't think it's anything to worry about in my case. Don't over crowd your beds; proper air circulation is key. Bacteria also need high humidity because they cultivate in water. Don't get your plants wet. Prevention with healthy plants is good too, they are less likely to have problems if they are not under stress. One website said prune the infected leaves. If the whole plant is infected, prune slowly over time so as to not overstress the plant.

That's all I've got for ya. Hope that helps!