This is my first year growing parsnips. Is it true that parsnip canker shows itself on the leaves first as a redish brown colour then a yellowing of its leaves as this is whats happening to mine.

My parsnips last year were massive, but had so many tails on them.what do you think.

My parsnip plants have started to get brown patches on the leaves. Do you know what this could be? I used to have them covered and uncovered them about three weeks ago.

I have small parsnip plants which I have had covered with a netting tent. I was wondering if I should take it off as it limits the amount of sunlight reaching the seedlings or should I leave it on to prevent any bugs getting at the plants.