hi! does anyone know about ringspot? what causes it and how to get rid of it? i think one of my dendrobium has it. it was on bud but for some reason, which is not clear to me at first, it got bud blast. then later ringspot came out of the leaves. actually, i'm not sure if it's halfway the spike when ringspot develop or afterwards.
please help me.
i'll try to post some pictures later.