Depends on what sub-server you're playing on. If you're on creative, which has a 1.12 backend, you should be able to use them. However, everywhere else the backend is 1.8 I believe, so you won't be able to craft/use any 1.9+ exclusive features. They just support joining with those higher versions, not the new features that come with them.
Also, if your farm involved pushing the sugar cane with a piston then it wouldn't work either. I believe the server has disabled these redstone contraptions because they are afk-able and having a afk-able melon farm for example would be OP since it provides a lot of income.
Ask Ankh said MCC is only 1.8 (1.12 on Creative) thus you are unable to use 1.9+ features on sub servers except for Creative Also, WolfgangLP also stated that pistons won't work either. This was to eliminate Redstone auto farms so people have to manually farm in order to progress. - Locked
