Hi not sure if i am doing this right but i have some parsnips who leaves have gone a brown colour and crisp to touch do not know why can any one help?
Have a very close look at the back of the affected leaves and check for tiny caterpillars. I have them on mine (last year too) and they eat all of the green matter from below, leaving only the upper surface and veins. The leaves then dry and go crispy. No-one seems sure of exactly which moth or sawfly is causing this - it may be an invader from the US and affects carrots, too. I had to spray with an organic bug spray as the rate at which the damage spread was incredible. There are threads about it on other forums: