I have a cycad that has just replaced all it's old fronds with new growth. These new fronds seem to be diseased. It looks like all the leaves are curling and are kind of white underneath. Does anyone have any idea why this is happening?
This sounds like a pest. Cycads have such tough, leathery leaves that they can only be attacked on new growth.
My guess would be mealy bugs and an insecticidal soap is the best solution to spray on as it dissolves their protective waxy coating and they then die.
Alternatively it could be scale - but less likely, if so then Pestoil sprayed in springtime is a good approach, it needs to be at that time as this is when they move around and they are more susceptible then.