Random pea plants dying

[ameno]

This has been happening to me for years, but I always find that about 20% of my pea plants will just randomly die when fully grown. When I pull them up, I find they have no roots, as though something has eaten them underground, or they have perhaps rotted.
Any ideas on what the cause is, and maybe how to prevent it?

[MillieBee]

I have this too, the plants go brown and dry as though they've had no water, but this isn't the case. I water religiously. I assumed it was because I had crowded them in somewhat (mine were grown in a tub). They are also on a shelf so it can't be critters....? Only affected maybe a third of them....

[bario1]

Is this after they've fruited? Pea plants will die off naturally when they run out of energy or they think they've set seed. Are there pods on the plants you didn't bother to pick? Mine are all dying off now.

[MillieBee]

well for me, I don't know how many pods they should have had, I got some right pathetic little wieners off them though! They seemed to start going brown and brittle before they'd produced very much.

[bario1]

Maybe a dozen per plant? Depends on variety i expect. How many plants did you have in all?

[ameno]

Mine die in mid-growth, usually just as they start to produce.

I've discovered what it is now, anyway, after doing some research. It's Fusarium wilt. Peas can apparently be fairly prone, and despite it being a soil disease it's not uncommon for only a few plants to get it. It gets a foothold more easily on weakened or damaged plants, and is more of an issue in hot, dry weather.
Crop rotation helps, but the main way to try and prevent it is apparently just to keep them well watered and be very careful not to damage the stems near ground level.