What is this?

[dfollett]

Originally Posted by KarenO

may not be strictly a deficiency of iron but rather an uptake issue caused by too wet, high soil ph, excessive phosphous etc. google iron chlorosis

KarenO

I had a similar problem with only a few plants in a flat showing severe yellowing. Karen's list mentions what I have concluded was the cause of my problem - High soil ph.

I add Garden lime to the peat based container mix I use. I recently purchased a new bag of lime. It is very finely powdered rather than the pelletized lime I have used in the past. I add the lime to the mix of peat, bark and perlite then stir it to blend everything. I think the powdered lime adheres to the damp peat it touches first and doesn't blend evenly like the pelletized lime does. That leaves a small portion of the mix (that portion with the limey peat) very high in lime and the rest with no lime. That portion of the mix heavy in lime will be much higher ph than the no-lime mix.

I'm not positive that is the answer to my issue, but that is the conclusion I've come to. Does my conclusion make sense to you gardening pros? That is the only answer I've been able to come up with.

[KarenO]

To me it does. The reason I said it appeared to be iron deficiency chlorosis specifically as opposed to general chlorosis is that the way it affects mainly the base of the leaves is typical.
KarenO

[Hellmanns]

I'll report back once my friend gets the test results back.

[KarenO]

if only 5% of his plants are affected that's good. Market gardeners I know always plant more than they anticipate they need so that they can cull the duds. Nobody will ever have 100% perfect saleable plants and 95 % is pretty darn good imo. If it were me, I would be interested in the cause but I would not try to fix the duds. I would not waste the space, time and water/fert on them.
I personally do not believe in nursing along unhealthy plants. Grow well or get culled in my garden. I have 120 day season and that is not enough time to mess around with sickly plants. I sure wouldn't buy any either.
I think it is most likely a pH issue especially if there was lime added to the mix possibly a bit unevenly so some soil is too alkaline.
KarenO

[Hellmanns]

Everything is being checked. We will see in a few days!

[PureHarvest]

The puckering/blistering growth is what has me confused. Seems to be a little more than just nutrients/limestone.
Looks like environmental/temp/water stress of some kind.
If water can't transpirate from the stomata, I imagine the leaves would swell like that and blister.
Why they can not do this is up for discussion.

[Hellmanns]

Test came back, no pathogens found. Soil was checked also, nothing wrong with it either. The plants look good now, and are going in my friends tunnel the 15th of the month.

[PureHarvest]

I've been wondering. Glad u updated.
I think the leaves couldn't transpire and swelled and puckered but that is just a guess.

[Hellmanns]

Originally Posted by PureHarvest

I've been wondering. Glad u updated.
I think the leaves couldn't transpire and swelled and puckered but that is just a guess.

Maybe so? Buffaloed me and everyone else I talked to.