I am home visiting my parents and they have had a majesty palm for few years. It's never really thrived as we live in Canada and are not gardening experts. Besides its yellowing, it also has small brown bumps as shown in attached photo. I would like to know what this is, what to do about it and whether it could be contagious to other tropical plants such as a banana tree. The bumps are mostly just on the branch in the photo but there are some on other leaves too. If anyone has experience growing this plant in a pot in zone 5 I'd be interested to know what worked for you!