Have more than just the bottom set of leaves burned? If so, how many sets up have started too burn? They could in fact be dieing out so that the plant can focus on vegetation towards the top... Pics would be helpful

Could be nutrient burn, I have had suger snap peas and regular peas suffer from nutrient burn reciently and it started from the bottom, was definately nutrient burn as my ppm was around 5000! I screwed up my mesurements, whats your ec or ppm? are the roots or even just the tips of roots looking black? Also maybe temp, I believe around 70 is when peas stop growing and start wilting and die.

If nutrient levels are OK, nutrient burns of that kind are only plausible at real overdose, check the stems for high moisture at the level where they get out/in the media. As peas tend to "damping off" due to their fine stems that stand in too (respectively permanently) moist media. In case, get drippers away from stems, if using E/F extended cycles are better than short cycles.

PS: peas produce nitrogen through the root nodules in conjunction with bacteria and need nutrients with low nitrogen levels.

Before you change anything, check for insects on the back of the leaves. I had some cucumbers that did the same thing. It turned out to be thrips.

"peas produce nitrogen through the root nodules in conjunction with bacteria and need nutrients with low nitrogen levels"

I have always wondered about that and hydroponics, are Rhizobia also found in water? what about those adding hydrogen peroxide?

Well, in some cases hydroponics is not just water. I guess their presence and thriving depends on your setup, the kind and the volume of media (organic like coco or rice hulls, etc - even river gravel) you use. And most importantly if you tend to "sterilize" regularly or let bacterial cultures establish. The crucial question still is if (or in what way) they usually establish. Is it only possible in soil or through soil, can they possibly migrate through air or are they even transmitted with the host (the plant) in some case? Are they able to exist in water, respectively nutrient solution? I know that it is possible to inoculate plants (with trichoderma, which is normally present in soil) through media and even by introducing directly in nutrient solution. In such case you wouldn't disinfect regularly of course. If settled "inside" the host, they are safe I guess, aren't they? Yet, I guess I have to admit that I haven't thought this fully through until now... ;-)

One more thing: we tend to distinguish between water and soil. But in fact there always is some "soil" in water (unless it is distilled), and in soil there always is some "water", or humidity if you prefer. In fact plants do not uptake anything from soil, but only in the form of dissolved ions and thus actually from the "water" in the soil. Not sure about this, - but I believe that Rhizobia, even if said to be "soil bacteria", may in fact get to the host in the same way as nutrients do... ;-)

Hi All:

Below is a link to a photo that shows the stem of the plant and a dead leaf. The leaf drying extends 3/4 up the plant in some cases. We did have some unseasonably hot weather here last week with one day hitting 79 degrees. It would have been hotter in the greenhouse. I don't see any signs of pests and I used Burpee booster (nitrogen fixing bacteria for peas/beans) in the planting media to help the plants fix nitrogen. The planting media is 90% perlite and 10% vermiculite.

Here is a link that might be useful:

How often do you flush your Perlite. Perlite is a holder onto, a collecter and a gatherer. The roots in Perlite join so they too get the fertilizer. But if only certian nutrients get absorbed the rest builds up at the point where the Perlite meets the roots. I think you need a good flush.

I agree, a (manual) flush couldn't do any harm and could indeed help if there is some nutrient/salt build-up in the Perlite. I don't exactly agree with georgeiiis detailed explanation, - just saying, it doesn't matter much... but I'd simply call it a general accumulation of salt residues and precipitations in the Perlite, that originates from unused nutrients.