My take is first thing I have read the tree by the rivers take and I must say I disagree. Jesus never has need for anything. He is the almighty, omnipowerful God. He wants something he has it.
Anyway, My take is that Jesus had come to the barren fig tree and used it to symbolize the man. The man as a christian had not beared fruit for three years and I think God is trying to tell us that if our christian tree doesn't bear fruit then it is more useful to be cut down. As christians we have a spiritual fig tree and It is our job to make it bear fruit. And that comes through studying the Bible,praying, and believing and working for the Lord. If we do not do these things and our tree's do not bear fruit than we are useless as christians. That's my take. Love ya Jim