When I try to put them on a crops, nothing happens
pic: http://imgur.com/mQtucgc

They probably don't have the JSON file set up for them. You'll have to create it. Apparently there isn't one for it by default. Basically just copy the wheat one, change the textures (make sure you match the number of stages nether wart has), change the soil (soul sand is a pre-defined soil) and set the seed item and drop. Should help.

Yeah... I must have missed creating a JSON file for nether wart in the port.

Can u write code for nether wart ?

I believe this works: http://pastebin.com/P8CqjMqe

I added a default JSON for nether wart.