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 Post subject: Lettuce problems
PostPosted: May 13th, '19, 17:24 
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Hello all,

I have been having a persistent issue with some of my lettuce. Older leaves become blotchy with yellow and brown spots all throughout. You can see the pictures below. I have tested my water, the sodium is very high, but that is. As for the insects, I am spraying Spintor (Spinosad) and BT alternating each once a week. The center of the lettuce heads are fine with a very nice green color. Can anyone tell me if they have had similar issues, or have an idea of whats going on here.

Any help is much appreciated.

Thanks


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 Post subject: Re: Lettuce problems
PostPosted: May 18th, '19, 02:56 
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Looks like it could be a problem with one of the mobile nutrients since only the older leaves are affected. Magnesium seems most likely but couldn't find any pics on the Internet that match this exactly. Potassium would be the next most likely but usually have the edges turn brown with this and not so much between the veins.

You could try spraying with an Epsom Salt solution that should help if it's magnesium but you'll probably need to repeat the spray every two or three weeks until the problem goes away (1Tablespoon per gallon should be about right). Spray application should avoid any problems with the system water that might cause the nutrient to be locked out and unavailable to the plants. Don't spray during the hottest part of the day, go for either the morning or late afternoon to reduce the risk of plant injury.

I don't know if the high sodium levels in your solution could cause problems with uptake of magnesium or potassium by your plants but all three ion have positive charges.


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 Post subject: Re: Lettuce problems
PostPosted: May 18th, '19, 17:50 
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Hi,

Have you tried examinating the leaves with a microscope, or a good magnifier ?
Looks like pests to me rather than a deficiency...

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 Post subject: Re: Lettuce problems
PostPosted: May 19th, '19, 04:11 
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Outer leaves with those spots are IMHO, are old and die off. I'd trim the plant showing signs of old age and death. The new growth looks green and your fish are alive... your are doing this correctly! :D


Good luck.

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