grey mould? :s

ok boys and girls, i left my greenhouse door SHUT when it was 32 degrees over here, totally forgot allabout it, wasreal humid in there, ive spotted some grey lookin stuff on the bottom of my plant, and its workin its way up to the main4 branches... wtf shall i do ive been told to chop the infected branches...any ideas.

and this was 5 days ago, thought id let it go but it starting covering some bits...

Cut the affected parts off now....it spreads and grows fast. AND your fan can blow mold spores around to share with the other plants......luck