Black Pine Needle Casts and Blights

After more then a year of training my Japanese Black Pine bonsais are doing well until lately it develope brown spot dan discolouring ring on the younger needle. I had read a few web site and compared it and i think it might be pine needle cast a type of fungas diesease n it can happen if the pine is planted under shade and moist enviroment.
I had this limitation, i live in a flat where my pine got 4 hours of sunlight per day. In tropical Malaysia sometimes it rains every evening for almost a month.
Can some one please tell me what fungicides or any remedies to treat or control it.

You can take a look here about my pinus sylvestris.
Will Baddeley is suggesting copper based fungicides and I did as he advised and my tree is doing really better. Thanks to Will! I have already sprayed 2 times

Thanks

My Nellie
After i spray Kocide to my pine, what shall i do. Should i let the fungicide stay on the pine neddle or flush it off after a few days.
Thanks

Leave it on. It will have a fairly short life, anyway, since it is approved for crops that humans eat.

Keep and eye on your tree and reapply if needed.

Thanks You