Mold on my plant/main stim??

Hi guys ! I'm 8 weeks into my second grow and one of my plants has started to develop mold on the stim near the coco. Is this dangerous for the plant or ?? I've maybe hit the stem with water while feeding the plants (the stem is almost touching the coco)

How can I get rid of this ?
The plant itself looks good but it's behind clearly getting behind the others..

Thanks guys!

Could you dig out some of the coco underneath the stem where it's molding? I wouldn't want to see any mold anywhere. If it can grow on the stem, it could spread to the bud pretty easily. What's your RH and airflow like?